As a side effect of our time in Nepal for the Future Makers Nepal project funded by UNDP Nepal, I had a lot of opportunity to observe how business is done and, especially, where business is not done but could perhaps be done. Means, a lot of business ideas came to my mind. Some will be crazy, some will be worthless, but some will fit. Since I don’t know which is which, I have to leave it to people who are experts in Nepal’s business environment to sort them. I’ll just drop my whole list of ideas here, and you can do whatever you want with it. Most (but not all!) of the ideas have some original innovative element in them (means you won’t find the exact same idea published somewhere else.) Happy entrepreneuring
If you decide to implement one of the ideas below or the list provided a major inspiration for your business idea, I’d be super happy if you let me know. (You can comment below, message me on my profile page, or email me at email@example.com.)
(1) Low-cost off-grid electricity system for villages
This is a business opportunity for a small manufacturing business. The product is an off-grid electricitysystem for the unserved low-end part of the market. At a sales price of 50-70 USD, it will provide lighting, phone charging and operating a TV or computer. It can be so cheap because it does not include an inverter – it is not needed because essential electrical devices (LED lighting, computer, phone chargers) work with 12 V DC directly or via a DC-DC converter. The kit needs a small small photovoltaics plant to function in villages without electrical grid.
It would be made out of:
a discarded 12 V lead-acid car battery; it may not have the current carrying capability needed to jumpstart a car (needs ca. 1000-2000 W), but can still be fully sufficient for lower-power consumers (we need ca. 50 W)
a solar charge controller
3 LED bulbs for lighting, 12 V DC, 3-4 W each
an adjustable DC-DC converter with various tips, able to power a notebook or a LCD TV screen (only TV models that come with their own external AC adapter though, since that can be replaced with our DC-DC adapter)
wires and switches
(2) Neighborhood composting and biogas businesses
The concept of backyard composting is well-known around cities in Nepal and was practiced by many until getting used to urban trash collection. Currently, the idea is a hard sell (even though organizations provide ready-made vermicomposting bins for cheap) since people see little reason to get back to this.
However, composting could work as a business idea by operating it as a neighborhood-scale plant. Then, it can even be combined with anaerobic biodigestion as a first step, producing biogas cooking fuel. This might be better adapted for an urban setting than expecting everyone to add biodigesters to their roof for producing their own biogas. A compact, odor-proof plant design is needed that can work in a neighborhood-level plant, producing both biogas for the neighborhood and fertile soil for the local area, both of which can be sold.
Interestingly, even all kinds of paper (esp. cardboard and newspaper) are suitable for composting (see). And the paper types not suitable for direct composting can be converted to biochar as soil amendment. (By converting to ash, it should also be simple enough to measure potential heavy metal content, which is basically the only possible residual contaminant after charring.)
The biogas would be delivered in regular LPG cylinders at 20 bars (well within the ratings of these cylinders). One such biogas cylinder lasts about one day, so when getting a delivery of 3 cylinders twice a week it could be acceptable, esp. since the distance to the production site would only be a few hundred meters. It’s not that comfortable, but not much more uncomfortable than needing a 20 l drinking water container every second day.
Business model: in exchange for separating and contributing kitchen scraps, people would get the biogas fuel at a discounted rate (say, 700 NPR per month for a family, which is about half the normal LPG costs). In addition, compost is sold to local gardeners and in truckloads to farms around the city.
(3) Novel products from plastic trash
Nearly all plastic trash is currently landfilled in Kathmandu (and probably in all other cities in Nepal), but there are quite some ways to use it as a raw material in small businesses. The Precious Plastic project provides several tested designs for open source machines to build by oneself for manufacturing products from recycled plastics in small workshops. Product ideas include:
Road topping, construction and flooring blocks made from gravel and scrap plastic: The technique was developed by Prof. R. Vasudevan in India and is called “plastone”, see here. Among other things, this is great material for covering roads to villages, since laying it and repairing it does not require heavy / specialized machinery. Road pavement blocks would ideally be interlocking. These blocks can be produced from unsorted, mixed trash plastic trash. For a company doing that already (with a mixture of 60% mixed plastics and 40% sand), including videos about their processes, see NELPLAST Ghana Ltd..
Waterproof cover material: When poured hot on-site rather than into blocks, the “plastone” material referred to above can be used as waterproof material for covering foundations, as protective wall plastering (needs a way to apply it hot on vertical surfaces of course), and as replacement for blacktopping roads.
Upcycling PET plastic bottles: For example, they could be made into transparent rooftiles for greenhouses (or like here). In rural areas, windows and roofs for houses can also be made from this. Also, there are nice simple inventions to make rope from PET bottles, like here. Similarly, wider stripes of PET bottles can be woven into baskets etc… Machine designs and processes should be put into DIY manuals.
Injection molding from scrap plastic: By sorting plastic by kind (and optionally color) and making plastic granule from it, one has the raw material for DIY injection molding. There are several designs for DIY injection molding machines, the challenge is usually creating the molds. However, the artisan metal casters in Patan can help to create the two halves of the negative form. Either they would model the halves in wax first and cast them with their usual lost wax technique separately, or (much simpler) they can simply create the intended plastic object in clay, dry it, then dip it into a pot of liquid aluminium and cut the cooled-down metal block in half to get the two halves of the mold. Then, people can produce many kinds of (simple at first) plastic items in a small shop. Like containers, furniture parts, and large corrugated plastic sheets to use for roofing in villages instead of zinc sheets. A DIY plastic casting industry seems like an interesting thing to research the processes and tech for. For example, for sorting the plastic, low-tech ways to identify them fast and reliably have to be found.
Plastic boxes from scrap plastic: They would be made from 2-3 mm sheet material made from scrap plastic, and combined with stacking corners and edge elements made from plastic by injection molding, or from aluminium by metal casting. For cost reduction, re-usable aluminium molds made from steel or ceramics would be used. These boxes would be superior to the ones currently made from thin zinc-coated steel sheets (as used for roofing but flat) in some workshops in Kathmandu. A major application would be rooftop boxes on jeeps and buses for carrying loads.
Plastic shingles for roofing and wall covering: These would be used for roofing and wall covering, and made from plastic sheet material in sizes of ca. 20×30 cm. In contrast to the usual large plastic sheets used for roofs and walls, these are much simpler to DIY produce from scrap plastic. When made from transparent plastic like PET bottles, the shingles are also good for light inlets (not windows for living areas of course) and for greenhouses.
Blocks from scrap plastic: Solid plastic block are a great raw material for further products, since they are sturdy, weather-proof and simple to machine. Any woodworking tool, an improvised lathe, or a simple DIY CNC mill will do. There are multiple how-tos for making plastic blocks from scrap plastic at home (like here and here), and such a process would have to be upscaled to a small business setting. Then one small company could collect, clean and sort the plastic trash, another one would buy it and make plastic blocks, and others would buy the blocks to produce things.
3D printing workshop using scrap plastic: While industrial injection molding needs quite some effort and production volume because of the required molds, 3D printers can produce small quantities economically and can likewise use scrap plastic. This can be imagined as a business idea: a workshop with 10 or more open source 3D printers (like the RepRap series), printing parts for customers all day, plus some Filabot type machines that produce the required filament from scrap plastic.
Making wall insulation material from scrap plastic: Insulation will reduce heating fuel needs – relevant for Kathmandu Valley, but more so in the higher-up hilly area. Insulation material from scrap plastic is simply thin fibers extruded from heated plastic and formed into wooly panels, similar to rockwool / glass wool panels.
(4) Rooftop farming
This could be big in Kathmandu, since rooftops are unused space for most of the day. They provide plenty of sunlight, water in a water tank, a waterproof clean strong floor, and usually access with an outside staircase. The plants would even make the rooftop more beautiful, cool it in the summer, and thus also make the city greener and cooler when this idea would spread. The “landless urban farmers” would rent access to multiple rooftops in the same city area, and visit them regularly to grow things there, using high-yield urban farming techniques. A similar “distributed urban farm” concept in Canada is demonstrated here. Another set of small businesses would provide equipment for this, including soil (from backyard composting), waterproof planting boxes (welded from plastic sheets made from trash plastic), supports (from scrap wood, for raised bed gardening), and drip irrigation equipment.
(5) Neighborhood “total recycling” sites
Trash is quite a DIY resource and can be recycled to over 95% with DIY techniques on small scales. Would also work in Kathmandu: here, solid waste is 63% organic, 11% plastic, 9% paper, 5% glass, 12% other [source]. The organic part would be converted to biogas and compost in the household or a neighborhood-level plant, which is the most DIY part. Leaves about 36% for collection. Trash should not be concentrated too much for processing it – too much in one spot means bad smells and health hazards. Proposal: a neighborhood-level site that fine-sorts and safely recycles the remaining 36% of waste, also being a business opportunity. Users would get special cans to separate the trash in the household (since trash sorting is the worst work ever when done later). Products of the recycling plant would be plastic granule, salvaged half-finished products from metal, aluminium shreds and ingots (e.g. for aluminium casting in Patan), steel pieces for recycling, paper shreds to go to paper recycling plants, and glass, to also go to recycling. Since waste management in Kathmandu is still largely done by private companies, it should be possible to be another one of these companies, providing waste disposal to households for much cheaper fees than the others due to converting it to resources. For a great example of community-driven full recycling, see Japan’s Kamikatsu city [source].
(6) DIY washing machine and detergents
Seems many poorer people wash by hand in Kathmandu. Also, when using photovoltaics off-grid electricity, one cannot operate a household washing machine. But there are alternatives, incl. cheaper DIY recipes for the detergents. My colleague Natalia mentions for example that soap nuts are produced in Nepal - it’s a great natural detergent, and it seems not in widespread use at least in the urban areas.
(7) DIY low-energy fridge
Uninterrupted cold storage is a problem even in houses with backup electricity, since the inverter is often not powerful enough for starting a compressor fridge. This fridge should work with an off-grid photovoltaics setup, use extremely little energy, and be cheap and DIY. Something like the Australian evaporation coolers maybe?
(8) DIY recirculating shower
A major way to save energy and water. There is Showerloop as an open source design, and it should be possible to modify it to 20% the cost (ca. 120 USD then) or less.
(9) Lead-acid battery recycling
Recycling automotive and grid-backup lead-acid batteries is possible in a DIY process. It can include (1) use of special substances (like EDTA) that can revitalize nearly worn-down batteries, (2) making new batteries from working cells of broken ones, (3) exchanging or even recasting the lead plates to repair cells. The products will be well usable as photovoltaics batteries, while cars and trucks should better get new ones. But since lead is toxic and the acid is not harmless either, this is a bit difficult to do in a safe way. Probably not done in Nepal at the moment (?) since the techniques are not well-known, so it offers a business opportunity for small-scale manufacturing.
(10) Innovative basketry
Basketry is practiced a lot in Nepal, esp. the countryside. There are probably some innovative ideas, materials and techniques to do still more with it and make it a more “competitive” technique for the use in cities. For example, using 3-4 mm plastic filament as raw material, made from plastic trash using an open source filament maker like the Filabot. The original Filabot design was open source. It may not be anymore, but can easily be reverse engineered.
(11) Producing e-bicycles
Electric bicycles are rarely seen in Nepal so far, and there is a business opportunity for small manufacturing by upgrading normal bicycles into e-bicycles. The most expensive part is usually the accumulator, but one can use broken down notebook accumulators for it. They are usually available for free and >80% of their LiIon cells are still useful, although often with only 30% their energy capacity and current carrying capacity remaining. This however simply means a 3 times heavier accumulator, which is still acceptable for Li-Ion technology. Also, by charging these batteries to only 3.92 V (70% their capacity), they can last for 3000-5000 cycles rather than 300-500, making them about 8 times cheaper again (per Watt hour delivered).
(12) Producing cargo bicycles
Creating one’s own DIY cargo bicycle, to work better and faster than the three-wheeled ones seen around Kathmandu. They can also be produced with electrical propulsion with minimal costs of ownership for the batteries (see the point about producing e-bicycles for that).
(13) Producing electric tempos
There once were 600 electrical SAFA tempos in Kathmandu, but operating them is difficult because battery depreciation costs about 100 USD/month, nearly as much as wage and electricity costs combined [source]. However, battery costs can be nearly eliminated by replacing the 36 deep-cycle lead-acid cells with a 21s Li-Ion configuration, made from used Li-Ion cells from notebooks and powertools. They would be charged to just 70% capacity (3.92 V/cell instead of 4.2 V/cell), which dramatically increases their cycle life from 300-600 to 1000-2000, giving the battery a 5 times higher lifetime energy throughput than lead-acid. Given that 18650 Li-Ion cells from broken notebook batteries have on average 3 Wh/cell left (at 4.2 V/cell) and that just 1.7 Wh/cell are required for the same energy density as lead-acid batteries (which is 36 Wh/kg at 60% depth-of-discharge), a battery the same weight as the original lead-acid battery pack and charged to 3.92 V can carry the same energy. By selecting cells with at least 4 Wh/cell (also easily possible), a 70% charge leads to 2.8 Wh/cell, which is a 50% range increase over lead acid given the same battery weight. So about 120 km/charge when assuming the data from SAFA tempos referred above. Moreover, investment costs are further decreased by needing only one battery pack rather than two as for SAFA tempos – Li-Ion batteries can be charged in about one hour to 70% rather than taking 12-16 hours as for lead-acid batteries.
(14) Glass handicrafts
Simple to do, even in remote areas, using a hydrogen flame (from PV powered electrolysis) or gasoline flame (as used by goldsmiths, with a simple “bubbling device” for gasification). Allows recycling of glass waste. Instructions have to include Innovative, proven designs for glass products. For example, plates, cups, bowls and other tableware. And flat lids for canning, using collected glass jars and either a rubber ring or wax seal.
(15) Glass brick and glass shingle making
This transforms glass waste into useful raw materials for buildings. Both would be useful to build greenhouses, and these greenhouses would last much longer than polytunnel and plastic roof versions, which quickly degrade from UV radiation.
(16) Water filter factory
Instruction how to make ceramic water filters with local materials (clay, rice husk and water) are found here and here. These allow to make water truck water and rainwater well drinkable – not possible with just chlorine / iodine due to algae and other dirt particles.
(17) Producing separating dry toilets
Very DIY, and it means no blackwater sewage is generated by the household. Only relevant for urban (and of course rural) informal settlements, which are not connected to the sewage network at all. Everyone whose house is connected (which are basically all houses in managed / residential areas in Kathmandu valley) is not interested in an off-grid toilet, since there do not seem to be recurring charges for wastewater disposal.
(18) Erasable notebooks for schools kids
Costs for notebooks and pencils is a major cost parents have to bear for the education of their children, and often cannot. Creating notebooks from plastic film “paper” (like Tyvek) and pens with ethanol-based ink allows erasing them after writing by wiping with ethanol. It would pay off in a month.
(19) Flow Hive beekeeping
See honeyflow.com for the Flow Hive, a “revoluntionary” beehive that needs no centrifuges or other expensive and complex equipment for beekeeping.
On Alibaba, you can find many cheap Chinese imitations of the original FlowHive device – for prices that are reasonable for Nepali beekeepers!
(20) Fruit walls on existing terraces
The vertical walls along terraced land are currently not used for anything, but they are great as heat-retention “fruit walls” to grow fruit trees even where it would normally be too cold for them. See here how that concept was applied in Europe for hundreds of years.
(21) Fruit wall mountains
Nepal has many barren mountains where nothing is grown due to lack of soil and cold temperatures. However, they can be transformed into “fruit wall mountains”. Many of them are probably in protected areas though, where this would not be applicable. See here how the concept of fruit walls was applied in Europe for hundreds of years.
(22) Bicycle powered grain mill
(23) Earth brick boxes from recycled plastic
Small companies in urban centers would create stackable plastic boxes from trash plastic that are then filled with earth and stones and used as “earth bricks” for building houses in the villages. The filling can be the same material as with earth bag buildings, the container is just just more durable and more earthquake proof. Similarly to building with earthbags, these blocks must be able to settle over two years after being used in a building. For that, it is enough if they can telescope down into the next lower layer of boxes, with special Lego-style connectors to make interlocking layers still possible. Optionally, one can use two rebars running vertically through each block, or lashing strap loops compressing a wall from top to bottom. Blocks should let water run off at the outside rather than letting it run into the box.
(24) Earthquake-safe buildings from blocks of recycled plastic
The system was developed by Conceptos Plasticos in Columbia, co-founded by Oscar Andres Mendez Gerardino in or before 2009. It consists of interlocking, extruded blocks of plastic and slotted extruded beams of plastic. All plastic comes from recycling plastic waste, and can be mixed plastic of various sorts. Information:
To improve the system, one could mix gravel and / or sand into the plastic as a filler material, increasing the amount of blocks produced from the same amount of plastic by probably a factor of 3-4. To further improve the system, blocks can be CNC milled out of extruded cuboid blocks. This allows to build anything with this system in a Lego-like system, including complex shapes like vaults.
(25) Plastic water tube from trash plastic
Rather than importing it, producing water tube is simple to do with domestic means and properly sorted and cleaned trash plastic.
(26) Plastic particle board
A simple way of recycling plastic into something useful, by just melting and pressing finely ground plastic waste together between heated steel plates into a particle board. It would not be a massive plastic sheet, but have many small air cavities, but that is intentional. The product would still be a great building material for furniture, boxes etc…
(27) Bamboo reinforced plastic
Bamboo has long straight fibers that can be easily extracted (e.g. from trash pieces). So by interlaying plastic film layers (e.g. from trashed plastic bags) and bamboo fibers, with the fibers turned 90° against the direction in the layer below, one can create very sturdy sheet material, much more sturdy than if just using the plastic from the plastic bags. At the same time, the material will be light (lighter than massive plastic sheets) and resistant to rot, unlike bamboo itself.
(28) Add-on electrostatic air particle filter for trucks
Fast option for better air quality in Nepal: Every large truck coming into the city will get a high voltage based air particle filter mounted to the exhaust, and will have to hand it back when leaving the city.
(29) Mobile trash recycling unit
A 20 ft ISO container with equipment and workplaces to sort all kinds of trash, for proper reuse and recycling. The unit would be put on a trash dump site, a wheeled loader would put in trash in one end, and sorting results will be dumped into various heaps and smaller containers around the ISO container. Results will be “for reuse”, “for reuse in parts”, various materials for reuse as raw materials (aluminium, steel, different plastics, copper, stones, glas), and organics to use for methane generation and composting. Sorted goods will then be cleaned and sold to manufacturers and scrap yards. The advantage is that this container will offer safe workplaces, compared to poking around in the trash as done currently. People will be completely isolated from the trash through climatized manipulator-like suits for the upper third of the body, accessible from the “trash-free” area below the surface to which they are mounted.
(30) Smog-filtering device that produces bricks
Smog-cleaning device that collects the smog dust and creates bricks from it. This is meant for massive-scale outdoor air cleaning. A device for this purpose has been developed in the Netherlands, see http://inhabitat.com/worlds-largest-smog-sucking-vacuum-cleaner-could-rid-cities-of-pollution/ . The additional idea is now to use the dust and burn it like bricks (possibly in a solar furnace). This will cause the dust particles to sinter together, just like clay. In this shape, they can be used as normal building material. It’s like getting bricks delivered over the air This will be especially useful in cities with horrible air quality that also includes coarse dust, for example Kathmandu.
(31) Street-sweeping cargo bicycle
The dust can perhaps be washed and then used as input for concrete, instead of sand.
(32) Biogas operated fridges
Biogas operated fridges for villages in Nepal. That’s very simple, just use the LPG operated camping fridges for that. They can be built from cheap used components (small broken camping fridges, insulation material). By using very thick walls (not a problem in villages as there is a lot of space), one can create very energy efficient fridges. Ideally, natural materials would be used for the walls. See for how to do it: https://energypedia.info/wiki/Biogas_Appliances#Refrigerators . An obvious improvement is power / cold / heat co-production: use the exhaust heat of a generator-driving combustion engine to drive the biogas fridge.
(33) Logistics platform
Both for ordering shipments within a city (like Kathmandu) and for national and international shipments. Incl. co-shipment and automatic logistical optimization.
(34) Autonomous electric footpath vehicles
See my dedicated article.
(35) Sky Bikes
These are enclosed, muscle powered cable cars running on aerial ropeways.
They work by having two cables: one cable between hilltops, keeping up a horizontal second cable that runs 20-50 m lower and is connected by vertical cables to the top one every 10 m or so. Alternatively, the lower cable would be replaced by an aluminium square profile with a slot opening in the bottom, with rollers inside. It is more expensive, but makes the mechanism of connecting the sky bike much simpler and more secure. In both cases, no pulling cable, electrical motor etc. is needed, as it’s all horizontal and thus very fast and easy to travel on that cable. Especially the aluminium profile version would provide a very smooth, horizontal ride.
The challenge is of course when using two cables, how to construct the system that suspends the sky bike from the steel cable above it, given that there are vertical cables in the way of driving forward, and that every 10 m. One idea is to have multiple (4-7) pulleys on top of the sky bike, with a special mechanism that allows to split them in the middle on demand, to pass a vertical cable. Another mechanism ensures that only one can be split / opened at any time, preventing the sky bike from falling down. The splitting surface would be toothed and its outside grooved, so that there is no realistic chance of accidental opening when closed, even when all closing force is missing. As an additional security mechanism, each sky bike would pull two ropes with special triple carabiner hooks behind them which can pass the vertical cables in a similar manner: only one carabiner can open at any given time.
The cable construction can be a loop so that the bikes can travel a full round trip, with some in store at each of the two end stations. It would even be possible to route these ways alongside hills (suspended on posts). Combining these two approaches, 10-30 km long “bike highways” can be built in the countryside that connect the village to the nearest road very fast. It would also be possible for these cable cars to carry load suspended below them (up to say, 600 kg total mass of the cable car, including the car, two people and the load).
It is also possible to extend this idea to be a network of skybike routes where the driver is able to choose his own way. This would use two pairs of hooks to connect to the cable. Two hooking from the left side, two from the right side. It has to be possible to switch the set automatically while driving. With the hooks from the left side, one will go left at a Y junction, with the ones from the right side, one will go right.
Another option for improvement are gas balloons, carrying most or all of the weight. This allows to use more lightweight steel cables, used just to pull the balloons, not to carry weight or secure against falling down. The advantage is that this allows mass use of blimp-based logistics, since the wind sensitivity, ground handling etc. problems are all solved then. But to make it usable for everyone, several changes have to be made. The cables should be installed permanently, with hubs on 10 m towers on hilltops. Because without rolling and unrolling the cables, they will last much longer. The cables would be used to conduct electricity, and the cable cars would have electrical motors and pull themselves along the cable. There would only be one cable between two points, so travelling is not horizontal. Changing direction by choosing a different cable can only happen at hub points. Possibly, a lightweight aramide cable inside an aluminium profile with a toothed outside (for the balloon to draw itself along) would be the best combination of cable weight, UV resistance, abrasion resistance and conductivity. It will be possible to use cheap hydrogen clusterballoons by letting them always float 30 m above the load (also great for avoiding ground contact with trees etc.). The load would travel in the cable car which is hanging below the cable. This will also allow to lower the load to the ground at any point during the journey.
For an independently developed, simpler version of this concept that is still applicable as a tourist attraction, see the video about Sky Bikes at Cascadas de Micos, Mexico. For another example that also includes turns and intermediate supports in the path of travel, see Zip-Bike Xel-Há (more videos here).
(36) Airdrops with guided parachutes for shipping to remote villages
The idea is using airdrops with guided parachutes of emergency supplies, urgent medical supplies and as a normal parcel logistics system for remote villages in Nepal. Of course, the same system can be used in to service any remote area worldwide.
For this to work, every village would have to designate and fence in a landing zone, ideally at a mountaintop. The area should ideally be at least 100 × 100 m, but even 30 × 30 m should be sufficient when the system is mature. The area would have to get some optical beacons and (if night operation is envisaged) some photovoltaics powered LED beacons. The parachutes would use these beacons during the final approach. In addition, the area should have a soft surface. 50 cm of pine needles and small dry branches, kept dry on a foundation of gravel, will do the job for example. An automatic system (or a person called before on the phone) would ring some bells before an airdrop, so people in the area can leave for safety in time. The “automatic system” for this could be as simple as a GSM phone number with a GSM device and loudspeakers at the drop zone.
One or two systems of GPS guided parachutes are already in existence, developed for military applications. This however would have to be a system of much lower cost, for rural developing areas.
This system would be quite cheap to operate, as normal fixed-wing aircraft can be used, and they can drop the goods mid-air during normal passenger flights, not needing to fly close to the ground as with normal airdrops. It could beat all alternatives (helicopter landings, drone delivery) by an order of magnitude. Note that normal airdrops are currently not an option at all in steep mountainous terrain, due to the lack of precision.
(37) Carry balloons
These are hydrogen balloons, probably cluster balloons for simple and safe handling, that are attached to ones backpack or other load, or even to pack animals. It would have enough lift to make carrying easier resp. to allow carrying more if one likes. At the same time, the baloon must be small enough to allow safe handling in slight winds. So probably, a 40 m³ balloon for 30-40 kg lift.
It is not clear yet how and where these would best be used. Of course, using this is only possible on open terrain, not in the woods etc… Maybe they would be used mostly for long-distance carrying to supply villages etc., but that will eventually be taken over by other means of transport because it also uses too much human time – except perhaps in combination with caravans of pack animals. Another use would be in agriculture in mountainous regions, for carrying tools, harvest, soil, compost etc. to and from the fields. Wheelbarrows do not work well in this terrain (too steep, too muddy), but carry balloons could.
The hydrogen would be created locally by water electrolysis, using excess photovoltaics energy.
(38) Chain bridges with pedal power
An interesting existing technology is wire bridges, see http://villagetechsolutions.org/transportation.html . They could be improved by using chains instead of steel cables (more durable, less likely to be damaged, and allowing traction) and bicycle pedals in the cable cars for pushing the car across, with gears getting traction from the overhead chain.
More details about this solution are found in our project “Chain tuins to cross rivers in Nepal”.
(39) E-bicycles with salvaged LiIon batteries
DIY e-bicycles, made in series by a company, from overstock and recycled LiIon 18650 cell batteries. These are available for 0.081 EUR/Wh, see for example this project: https://www.youtube.com/watch?v=Rjr2LKmhdVw . The cost of a 500 Wh accu pack will be around 40 EUR then, or (say) 70 EUR incl. all casing, soldering etc…
In addition, one would make these battery packs swapable, and build PV powered recharge stations on the way where one can simply swap the battery pack for a fresh one. Together, this will allow going nearly twice as fast by bicycle uphill and downhill as by truck or bus (which is around 10 km/h off-road, as per experience values). Still, the “fuel” is DIY produced in PV arrays. In addition, the bicycle accu packs would also be used as backup battery during the night, to power lights and computers when PV power is not available. A 500 Wh accu pack is fully sufficient for a family, as it would power a notebook for 50 hours for example.
(40) Slow-but-cheap international parcel service
A “slow parcel” service that combines parcels into LCL (“less than container load”) shipments from Nepal to Europe and the other way. With forwarding within Nepal / within Europe by appropriate means. This would be great to have for “very small businesses” to import and export.
(41) Using biogas as vehicle fuel
Like, research and instructions for converting a motorbike to biogas usage by attaching two LPG bottles with biogas at 20 bars.
(42) Foot passenger tunnels made with a micro roadheader
Small tunnels through a hill can connect the two sides of a hill in the hilly area of Nepal. That dramatically shortens certain ways between settlements and between fields and settlements, as travelling through a level tunnel is fast and almost effortless. Also it’s almost “magical” when a portal in your backyard directly connects you to a remote space. For some growing urban areas (Gorkha Municipality for example) it would be an interesting way to have a large and quiet private garden that will not be threatened by urbanization as it is on the other side of the hill, maybe 400-1000 m away through a tunnel.
A roadheader is the most versatile dunnel digging machine currently in existence. They are used, among other things, for digging out underground homes in Coober Pedy, Australia (see this article). An open hardware, small, CNC controlled roadheader device seems quite doable.
The problem will probably be rather social issues with tunnels: they are dark and will be considered “unsafe” esp. for women and children. That can however be solved by letting people travel through the tunnel with a small carriage that can be locked from the inside. There would only be one carriage in the tunnel, going back and forth, and due to a mechanical system people cannot enter the tunnel except into the carriage when it is docked at either end.
The carriage would have about four seats and would be powered like a bicycle by the passengers. There would also be a hauling cable so that it can be pulled from one side to the other without passengers, using a similar pedal operated system on each end.
(43) Producing autospades for agriculture
More efficient than hoes, and not requiring a plough. Seemingly not introduced in Nepal yet. They can easily be produced domestically in a small welding / metalworking workshop from scrap metal. See this page for the currently available product on sale.
(44) Producing bicycle powered machines for agriculture
If to be used on the field, they can be made light enough to transport up and down hills, in contrast to motorized machines (and electrical machines are excluded as there is no electricity in the field, and if there was, then not enough … ok except with generators).
(45) Combined biogas fired / solar powered food dehydrator
It should save energy by letting a batch of air saturate in humidity before exchanging it, and by heating incoming air with exhaust air using and air-to-air heat exchanger. This device will allow to dry food in harvest time close before monsoon, where sun is usually scarcer.
(46) Hydraulic ram water pumps
There are many villages located on hills which have little potable water, all while there is a river 200-400 m downhill. But since they lack electricity and the finances to purchase pumps, this water is not economically reachable. However, the hydraulic ram provides a water-driven way to pump water up to 600 m uphill. It is 25%-92% efficient. See the Wikipedia article about the hydraulic ram.
(47) Making terraces into passive solar greenhouses, for extended growing seasons
Passive solar greenhouses, built by using south-facing terraces, reusing the terrace wall for heat storage during the day. See this detailed article for the concept.
(48) Bioethanol fuel for vehicles made with syngas fermentation in villages
Use village-scale syngas-fermentation process plants to create bioethanol fuel from cellulose biomass. This process is esp. nice since it creates DIY biofuel that is simple and safe to handle and not environmentally detrimental if spilled. Also, its production uses the biomass waste in villages (which is a lot), so does not (have to) compete with food production. And since the only input to the fermentation stage is gas, there is no sludge or other difficult to handle output. In addition, the biomass can be stored for the winter where the heat from partial combustion in syngas production can be used for space heating and cooking (syngas production can be distributed, with small pipelines pumping it to a central fermenter; this also allows cooking due to higher temperatures, and it wastes no heat compared to a central gasifier and heat distribution via hot water pipes). In addition, the syngas can also be used to directly operate generators for local electricity generation (it would be a waste to go through the ethanol process for this; and again, waste heat can be used for space heating via CHP). Plus, one can do the ethanol distillation at no additional cost by doing it only in winter, using the gasification process waste heat and operating the distillation indoors in people’s homes, since this automatically reuses all distillation process heat for space heating. So one would collect biomass throughout the year, building an excess of it in summer, where gasification is only done for electricity generation (and waste heat used for cooking). In winter, where waste heat is needed also for space heating (and distilling), more gasification is done to drive the ethanol process. The end product (ethanol) is well storable, so seasonal storage is not a problem. Also, this creates a work opportunity for the “slow part” of the agricultural year, and even an income opportunity in winter, by selling the bioethanol. Finally, by doing incomplete gasification, biochar is produced, which is a great fertilizer for soil (see “terra preta”). One of the most interesting aspects is that this process can be economical for DIY production in villages even if it is not economical on the global market or even for sale inside the country (yet). Because it uses excess capacity (unused time due to lack of jobs, unused biomass) in villages and results in avoiding to spend always-scarce money on fuel and fuel taxes.
Among the waste biomass in Nepali villages that can be used for this is: pine needles from pine forests; rice straw; cow dung; twigs; wood scraps; bamboo scraps; gras; human feces (safe disposal compared to sludge from biogas generation). In total, the process seems to integrate very well with life in Nepali villages, running fully on current excess / waste biomass while generating fuel for own consumption and sale to city dwellers.
It seems that this process is ready to be used (with future improvements coming through further research), judging from the following links:
- "Commercial Biomass Syngas Fermentation" (great paper, summarizing it all in detail)
- English Wikipedia: Cellulosic Ethanol: Gasification process (thermochemical approach)
- German Wikipedia: Synthesegas-Fermentation
- German Wikipedia: Clostridium ljungdahlii
- Tirado-Acevedo, Oscar: "Production of Bioethanol from Synthesis Gas Using Clostridium ljungdahlii as a Microbial Catalyst". That dissertation esp. says that the competing (all biological) process is inferior at this time: "Fermentation of synthesis gas obtained from biomass has proven to be a viable approach to produce biofuels. This technology has higher product yields and lower energy input than lignocellulose hydrolysis fermentation." (p. 123)
- Regarding efficiency of this process: "Coskata’s proprietary process extracts more energy from feedstocks than competitive production pathways. [… O]ur process can produce […] 100 gallons [378 l] of ethanol per dry ton of softwood." [source].
- "Transportation Biofuels: Novel Pathways for the Production of Ethanol, Biogas and Biodiesel"
For a process design adapted to rural settings in developing areas, an initial proposal would be to avoid membrane bioreactors (due to expensive, high-maintenance membranes used to separate out a water/ethanol mix from the reactor to then obtain the ethanol by distillation and feed back the water). Instead, use immobilized cell reactors in batch mode (“liquid batch, continuous gas”). Use (say) ten batch vessels in parallel, with the syngas travelling first through the old batches (the bacteriae might still want to eat if offered concentrated food …) and then through the new batches. The by-product acetic acid is inhibiting via its pH. It might have to be removed by adding base, causing the formation of solid acetate salts. An interesting option for increasing the ethanol yield is adding a acetate to ethanol two-step process afterwards (as discussed here).
In total however, commercialization has not yet been achieved of syngas fermentation for ethanol production, as discussed here. This means it will be better to start with first-generaton (sugarcane based) ethanol production, which is not a problem until it uses all currently unused land in rural Nepal. This will yield the DIY distillation technology, while employing biomass gasification for electricity production (CHP), space heating and cooking will yield the DIY gasification technology. Research into the missing link (the fermentation step) can then be done in parallel.
(49) Biogas and bioethanol as DIY automotive biofuels made in villages
The correct DIY fuel for vehicles in Nepal is definitely not biogas or syngas, but bioethanol and vegetable oils. Biogas is fine for cooking and electricity generation though. Villages already have the required tech for bioethanol, since they already produce roxy Ethanol is much simpler to handle (high energy density in storage) and less dangerous (zero pressure during storage) and more or less a drop-in replacement for petrol. Villages have mostly motorbikes, and these can run on bioethanol. Buses and trucks will still need diesel (but that can be replaced with vegetable oil later). Also, ethanol can replace LPG for cooking in the cities easily (with gasification burners being readily abvailable). This creates greater fuel independence in Nepal (politically wanted) and at the same time creates an additional market for village products, increasing the economic viability of villages.
The challenge is to find plants that can be efficiently farmed manually on terraced farms, produce marketable food, and bioethanol from the sugary remains of food production. But when it all adds up, meaning farmers can make an attractive income from producing bio ethanol, the fields in villages will be all in use again, and people will not have to emigrate that much since they can earn enough at home.
A tested and tried process would be sugarcane as energy crop, as extensively used in Brazil. Calculation of required area: In Brazil, current yields are 6000 l/ha of pure hydrous ethanol (E100), with 9000 l/ha targeted through further improvements. With lower tech but more manual labor for farming (usually increasing yield), 5000 l/ha seems possible. Assuming two trips per week to the next city (4 x 30 km) per family, at 3.75 l / 100 km in a motorbike, this would need 127 l/year of ethanol, per family. At 1000 people / 250 families for a typical village, this would need 31750 l, requiring 31750 l / 5000 l/ha = 6.35 ha of land, an area of 251 x 251 m. Or for each family, 63500 m² / 250 families = 254 m²/family, or 16 x 16 m, or one 42 x 6 m stripe on a terrace. This is definitely doable. The mobility enabled by this is not “great”, but useful. Public transport would of course be the normal mode of transportation, but a motorbike will enable more flexibility when buses don’t go during monsoon season etc…
It is said that in the hilly area, there is only 0.05 ha (500 m²) per person of cultivated land. Of this, 63.5 m² (13%) would be used for bioethanol production, which is quite a lot given that it competes with food crops. However, reportedly there is now land falling barren in villages, since in many villages so many laborers emigrated that none are left to farm the land. Attracting sugarcane production here is not a problem for food security, then. It can become one when people migrate back to villages since employment options improve due to biofuel production. So in total, it would be much better to produce biofuels that do not use up land.
When using sugarcane, the residue can be used for biomass gasification (syngas production), for ethanol distillation (indoor, enabling waste heat reuse for space heating), for cooking and electricity production (with CHP for waste heat reuse). This way, sugarcane replaces firewood, avoiding detrimental effects on the local environment. Still, it used up some arable land, but as long as there is unused arable land (as now, and worsening), that is not a problem.
Another possible process could be using fruit trees (low maintenance “edible forests”) to create fruit juice. Then create fruit bars, paper etc. from the pulp, ferment the fruit juice, and if needed keep it until the following year when there is enough sunshine again. Then distil the ethanol out using a solar powered distillation plant. Use low temperatures, as that should allow to also use the remainder as fruit juice again (?) or for other purposes of nutrition. Also, sugarcane is a reasonable plant to use.
(50) Biogas driven small generator
A very small combination of an internal combustion engine and a generator, with (say) 100 W electrical output. This is way enough for electricity needs in a rural village. Run it for 3 hours a day, and operate a notebook and light bulbs throughout the day. It would use 80 - 100 l biogas per hour to generate 100 W electrical output (see https://energypedia.info/wiki/Biogas_Appliances#Efficiency ). Four-stroke model aircraft engines that can be converted to this are available for 150 USD (new).
(51) Biogas electricity plants for villages
A combination of biogas, a biogas based electricity generator, biogas storage facilities, and photovoltaics is a reasonable solution for permanent electricity supply for villages. In addition, syngas from biomass gasification would be used when not enough biogas is available.
(52) Charcoal fuelled generators
Box sized (for a family) or pallet sized (for a village ward) generators that run on charcoal. See EarthOS for the design. Village people can then produce the charcoal as a side product whenever using a cooking stove or heating stove. Ideally, the generator would use CHP (“combined heat and power”), producing space heating and even pre-heating for cooking as well, so hardly using additional fuel. This allows electricity generation on demand, lowering the required battery capacity for photovoltaics plants (thus making them cheaper). The generator would have automatic start and stop, and automatically top up the batteries when needed.
(53) Electricity from pine needles
Using pine needles (and other currently unused biomass) in wood / biomass gasification, then driving generators with it. And cooking on the gasifier. There should be a small intermediate storage in an unpressurized gas envelope, with a lot of free space around, just enough to keep a generator running for several hours after cooking (6-8 hours if cooking twice a day). Storing larger amounts of carbon monoxide, esp. if pressurized, is really dangerous (0.5% in air is deadly in 10% of cases already …). The generator should start and stop automatically when power is needed, combined with a small battery backup which will supply power <50 W and higher power for a few seconds until the generator has started.
(54) Motorcycle fuel from DIY biogas plants
DIY biogas plants in villages with compression and use of the biogas in motorcycles. This is done by: (1) building a normal small biogas plant, as presentin villages in Nepal already, (2) optionally converting the contained carbon dioxide to methane to ramp up the energy content, by inserting hydrogen into the digestion process and letting the bacteria do their work (hydrogen would be created by electrolysis, using excess photovoltaics energy), (3) cleaning the corrosive H2S from the biogas (bacteria can help), (4) compressing it with a fridge compressor (can create up to 40 bars even, see http://hackaday.com/2013/09/17/high-pressure-air-compressor-using-a-pair-of-refrigeration-compressors/ ), (5) storing it in LPG bottles (they can hold 18-20 bars safely, see http://usersites.horrorfind.com/home/halloween/wolfstone/HalloweenTech/pnupro_PropaneAirTank.html ). One 15 kg LPG bottle has 30 l volume, see https://www.elgas.com.au/for-business/forklift-gas-bottles-cylinders/forklift-gas-bottle-cylinder-sizes-dimensions-capacities . Which means that at 20 bars, it can store 600 l biogas, or about 0.5 kg (if all is methane). A motorcycle can carry two such bottles (one left, one right). At 4 kg / 100 km, that 1 kg would last just 25 km. However that fuel is free, and there is a village every 25 km for sure in Nepal, and every village could have its bottle swap station. The fuel would be inserted as a co-fuel into the air intake, and when running out of biogas after 25 km, petrol from the normal tank will be used.
(55) Photovoltaics battery charging station for villages
Meant as a first, quick electrification measure, not as an ultimate or permanent solution.
There would be one photovoltaics plant in the center of the village, or one per village ward, each plant with 3-6 kW§ per 1000 people, mounted on a large central pillar, or the roof of a school, or similar. Then, there would be a vending machine style device that can be used to exchange discharged batteries to freshly charged ones, always 1:1, with proper detection that a battery is inserted and not a stone. Of course it would be better to do without batteries, but even cabling throughout the village does not help since photovoltaics energy has to be available when there is no sun. And then, when batteries are needed anyway, it’s better to use them in a way that avoids the need for cabling (which is expensive to install, error prone, and inefficient for low voltages).
Now everyone in the village will receive 2 batteries (18650 LiIon cells harvested from notebooks, with added protection PCBs). And the villagers can self-organize how to get discharged batteries exchanged for charged ones: either going there themselves, or sending a family member with batteries of the whole family, or having somebody walk the neighborhood with a special bell every day to exchange batteries on the spot (by wearing a set of, say, 100 charged batteries and exchaning them for discharged ones). Possibly, the “manual solution” of somebody going around to exchange batteries can or should replace the vending machine, by simply giving that person exclusive access to the PV station’s charging chamber.
This “much” electricity (2*8 = 16 Wh per day when exchanging both cells) of course must be used very efficiently to be sufficient. It is however enough for lighting via a brightness adjustable headlamp and to power a smartphone, FM radio and e-reader for some hours (via a USB power bank or by inserting the cell into a device made or modified to allow this).
In a second stage, there can be 24 V (6s or 7s configuration) battery packs containing many of these cells and being exchanged in a similar manner. A notebook sized 48 cell pack would contain about 300-400 Wh (when made from remanufactured, already weakened cells) and should allow to power a household’s home for 3-4 days with energy efficient devices. Even power drills etc. can now be used.
A business model can be developed on top of this: recharging individual cells would be free, but for recharging the big battery packs people would have to contribute in kind (food, handicrafts items, cow manure for a biogas digester or similar). Plus, excess electricity which will be available over the summer could be used to offer additional paid services or machines for rent at the photovoltaics station: grain mills etc…
(56) Village ward biogas plants
One biogas plant per village ward, not per household. Biogas would be delivered in uncompressed plastic bags, ca. 1 m³ per household per day. This solves the problem that many households can’t afford a biogas plant – a larger, combined plant (say, for 50-100 households) is much cheaper than 50-100 household-sized plants. Alternatively to the gas bag delivery, a simple network of 30 mm diameter flexible plastic pipes (35 mbar pressure) could be set up. People would have to deliver their bio waste to the plant (human manure, animal manure, veggie and fruit scraps). It would be delivered in buckets by the inhabitants (in the case of human manure, this limits spread of infections). If there are larger amounts, gravity fed sledges can be built for animal manure and food scraps, starting at houses or central points.
(57) Metal 3D printing studio
It would use 3D printing in wax, or CNC milling of wax models, then the traditional Newari lost wax metal casting technique, in aluminium or bronze or tin (or whatnot). See https://www.youtube.com/watch?v=FRSRCY2LzAU for a demonstration of that technique. So the data would come from people (abroad, overseas etc.), the production would be done in Nepal, and the finished objects would be sent as prepared and labelled parcel as co-shipment with tourist luggage to the international clients. This would probably be a super well running business, since, it can offer printing huge metal models for super attractive prices, probably less than 10% of what it would cost at Shapeways etc… Artists from all over the world, and also some people needing custom machined parts, would use the service.
(58) Pressure canned village food
Using pressure canning to cook and preserve local food (incl. full dishes) made in villages in Nepal. This can then be transported to cities safely, and used as sauces, for ingredients etc. in restaurants. It can also be sold tourists who love Nepali food and return home with a few cans of it (which routes around all the crazy food safety regulations one would have to deal with for regular export / import of such food).
Note that there are two different techniques: normal canning, and pressure canning, which works at higher pressures and temperatures. You need to look up which technique to use for which food to can it microbiologically safely, and also the timings and temperature – usually fruits and other sour items can be canned, and meat etc. has to be pressure canned. About the canning device: the All American Pressure Canner is a suitable device for example, since it can even be used on an open fire. See: “Pressure Canning on a Rocket Stove”.
(59) Sell Nepali coffee to returning tourists
Means, set up a small roastery. Get a roaster, scales, packaging equipment, a good label design. Create good, original Nepali coffee, roasted and packaged in 250 g and 500 g packs (which are the most usual format in Europe).
For selling, have a stand at Tribhuvan International Airport in Kathmandu to sell to returning tourists. This should include a billboard with information about coffee import regulations per destination country (esp. free-to-import amounts), free baggage limits per airline, and scales so people can find out how much they can buy to add to their baggage for free.
Tourists’ baggage as a means of transport for coffee for personal use works around the transportation cost problem for coffee exported from Nepal (which is currently only possible by air cargo for less-than-container loads). It also works around problem of customs, because normally exporting coffee only makes sense in larger amounts (>500 kg) and then as green beans (as the large amounts usually can’t be sold fast enough for the coffee to keep fresh – roasted coffee stays fresh at most two weeks).
(60) Export psychedelic honey from Nepal to Europe
There is psychedelic rhododendron honey in Nepal, made known to the world by the VICE honey hunters documentary.
The fun part is that customs of European Union don’t know about psychedelic honey – you can import and sell it as normal honey, not as a controlled psychoactive substance. When doing that carefully and responsibly, and telling customers exactly what they get and how to use it, it is probable that this would be a sweet niche market with high margins for several years, until it might become forbidden or regulated. (And if that happens, there are of course many other markets worldwide as alternatives.)
The proof (to the best of my knowledge but without any warranties) that rhododendron honey from Nepal can be imported the same way as normal honey:
Have a look at the EU regulations for importing honey from Nepal in TARIC. Basically it means: when importing honey for resale, you need: veterinary certificate, may go through veterinary inspection, duty rate 17.5% (or 0% “development country preference rate” for the India / Nepal etc. group of countries if the shipment value is >5000 EUR).
This seems to mean that there’s no controlled substance regulation for honey (psychedelic or not) because if there was, there would be a condition “restriction of entry into free circulation” as, for example, for importing hemp seeds from Nepal.
There is already a (Kathmandu based) company selling that honey online now: The Mad Honey. Their prices are really attractive for sellers, given that this honey is sold locally by those who harvest it for 1000 NPR/kg or similar (as reported by a friend who bought a few kilograms in Rukum or Rolpa district).
(61) Travel through Nepal’s villages and sell coffee farming machines
That is, sell small machines for coffee processing, and teach farmers about coffee farming, and leave coffee farming manuals. Farmers in Nepal need processing equipment and knowledge more than trade connections in order to be able to make a living from coffee farming, since prices are really high in Nepal when compared to other countries.
(62) Sell own handicrafts products on Etsy and DaWanda
This is part of the general principle that selling unique products on international markets can work, even though international shipment of small lots is prohibitively expensive for non-unique products.
(63) Become a remote web software moderator / admin
Nepal is becoming an attractive outsourcing location for computer work due to the good English skills of many in Nepal, and the low wage level after considering the currency exchange rate.
The problem is how to find a foothold in this market as a freelancer / solo entrepreneur. A recommendation is to look up modern, trending open source software packages that are used by large community sites, forums and social networks. For example Discourse, potentially the world’s most advanced open source forum software. (We also use it right here on this website.) By looking at open source software only, you can be sure that (1) it will be in widespread use and (2) you can learn it without paying any money because you can install it on your own computer for free.
Note that this work does not require programming skills. If you can work well with complex software like Microsoft Word, you can become a Discourse moderator. That work consists of sorting and tagging content, moderating discussions, deleting spam posts and spam users, offensive posts etc… You can then further extend your skills (and increase your pay) lateron by learning Discourse admin tasks: handling backups, repairing the database, managing e-mail problems, learning Ruby console to extract information from the database and script / program custom changes to content and settings etc…
So after you selected the software package you want to specialize in, and learned all the basics on your own from online materials, you can then look for sites using that software and approach them as a potential addition to their team. Most of the organizations behind these sites will not even have thought about outsourcing work to other countries, but when you explain it well to them and demonstrate your skills, it will be attractive for many of them. Because a freelance consultant working over the Internet from Nepal as a web software moderator and admin is at least three times cheaper than their local staff in Europe or USA. I assume that for a well-experienced Discourse admin from Nepal, for example, an hourly rate of 7 USD is realistic (not for a novice, for somebody with at least 3 years experience).
(64) Outsourcing agency for web platform moderation / administration
Building on the last business idea (no. 63), it is of course also possible to transform a solo web moderator business into an agency by training employees in Nepal in the moderator and admin skills you acquired. A bit like Cloud Factory (a great startup from Nepal actually!) but more specialized and on a much smaller scale.
(65) Produce GoSol solar cookstoves, dehydrators, ovens and roasters
The GoSol SOL devices are a proven and tested technology for direct solar thermal use. Like the solar stove devices that have been around for a decade, but much more powerful (up to 6 kW) and they actually work. This is applicable for all areas in Nepal with a lot of direct sunlight (means, little cloud cover) and little firewood for fuel. So especially for the trans-himalayan highlands.
In addition, the technology is also useful for commercial operators in cities, for example coffee coffee roasters and food processors (fruit dehydration etc.). The rooftop terraces are an obvious choice of location. For commercial use in cities, fully automated operation would be desirable, as human worktime is more expensive in cities. Which would be a nice addition to the GoSol technology. For roasters, you could base this automatic solution on the open source Artisan Roaster Scope software, combined with Arduino TC4 boards to actually control the roaster’s fan and heater. Add in some nice weather forecast incl. cloud cover prediction so the roaster knows when there is enough sun in the next 20 minutes to start roasting a batch. This can be built on top of OpenWeatherMap, which provides a 5-day forecast with 3 hour granularity, and updates every 3 hours.
(66) Open source optical sorter for coffee beans (or nuts etc.)
A small-scale, cheap optical sorter for green coffee beans and possibly other agricultural products. You can build a coffee processing business out of this (much better than sorting coffee by hand as usual …) or you could produce and sell these machines in Nepal, as the design will be open source.
First, we have to develop this machine together, though. For that, and all other details, head over to my initiative to get this machine funded and built. Welcome to get involved (this project is actually happening now!).
(67) Traffic jam bicycle
Essentially a new, faster means of transportation in Kathmandu: a bicycle that is optimized for driving through traffic jams. It would be faster than all other means of transport in Kathmandu during peak traffic times and probably during most of the day. To be fast, it can be a powerful electric bicycle, but the concept can also work purely mechanically.
Its features would be a narrow handlebar, thick foam cushioning on all outer surfaces to not scratch vehicles, and a vertical rotating flywheel to provide high stability when driving very slow between vehicles. In addition, a saddle that can be lowered with the touch of a button to be able to balance the bicycle with the feet on the ground when slipping through between vehicles; afterwards, one would flip the button again and the saddle would move up again to a mechanical upper limit. This would be provided by compressed air from a mechanical wheel hub air compressor that can be pumped into and let out of a “normal” cushioned saddle tube.
(68) Mountain farming on newly deposited soil
This idea is for those looking for an “extreme farming” challenge. Due to the changing climate, many mountain areas that were too cold to cultivate anything are now potential locations for farming. There are huge tracts of land in the wider Himalaya area that are completely unused and barren, with no competition for using or owning them. Their big problem is of course that still nothing grows because there is no soil:
There is also an upper limit to how far plants can move [uphill] since there is no topsoil at extreme altitudes to support plant life. (source)
But soil is just compost mixed with pulverized stones and ideally biochar, in the right quantities. So if we transport biomass from the closest location that has it (which may be in the valley near a river), create the crushed stones on site and mix it, we have the soil. Now it has to be deposited in an erosion-resistant way (in pits, ditches and human-made or natural terraces), which is obviously a lot of work and requires a small excavator with a hydraulic jackhammer. And then more work for solutions that direct the rainwater to the plants, and store it where needed.
But it’s rewarding: climate change can be used to increase the available farmland and also the land available for wild plants and animals.
(69) Alibaba delivery service
The Chinese website Alibaba Express is a treasure for getting all kinds of equipment and spare parts. Even in Europe, many spare parts are only available on Aliexpress – you might get for example a whole laser printer fuser assembly for 100 EUR right in Europe, or just the broken fuser roller inside it fro 9 EUR from Aliexpress.
And Nepal is much closer to China, so delivery can be organized in less than a week using cheap overland transport. The way to organize it would be to have a proxy shipment address inside China at the train station closest to the Nepali border (Lhasa). Everyone from Nepal ordering from the normal AliExpress website just orders their stuff to go there. Then the company at that address organizes one car or truck transport per week to bring the items to Kathmandu and to distribute them in the capital themselves, and in other cities and areas by postal service.
(70) Producing supercap-buffered systems for solar self-consumption
This is a new idea that can make rooftop solar cost-effective where it is currently not: namely, in all places where people have access to the grid but are not rewarded for exporting excess solar electricity to the grid. The system can be easily produced in Nepal from locally available components, and supercaps (which will have to be imported).
The idea is explained in detail here.
(71) Solar electrical cargo bicycle
This can be built on the basis of an existing cargo bicycle of various types (in Nepal: the Portal Bikes Long-Tail), or of course also by building the portal bike oneself. Cargo bicycles of various types can be used since the modification is about adding solar-clad boxes. However, the single tracked versions (Long Tail and Long John types) may be the most suitable in the hilly area as they can go on single-track paths, and of these the Long Tail version has better off-road capabilities. The case study below is for Long Tail bicycles.
The solar electric version would consist of a box over the back wheel, and maybe a smaller similar box over the front wheel, with extensions down to the wheel hub. So the box has flaps on the left and right to access it, and is about 50-65 cm wide. The flaps and top, and maybe the back resp. front side, would be covered in photovoltaics panels. In addition, below these panels another layer of panels can extend to the back resp. front, for about 2/3 of the length of the box. In addition, in low traffic conditions and when stationery, the flaps can be aligned to the sun, by folding them up to 180° up. Together, that would be up to 600 W§ of photovoltaics panels. The solar panels would be of the thin, plastic covered type to save weight, and to protect them there would be a wire mesh in a distance of 5 cm and bumper corners and edges. So even when the bicycle falls over, the panels must survive. This should also make it possible to use the top of the box as carrier rack (which should be in a height of ca. 130 cm because it should be possible to lock backwards with the box mounted). To lift the bicycle over obstacles, it should be possible to detach the box and carry it like an external frame backpack.
For the electrical system, a hub motor (better for hills) will be used, and ca. 30 Wh of supercaps and a small Li-Ion battery. The stored energy should be just enough to drive up a typical Nepali hill (ca. 600 m altitude difference) when combined with human power and a little solar input as seen on cloudy days. On sunny days, it will be easier and faster as the sun will do most of the work. More than driving up one hill is not needed, as energy will be produced from regenerative braking on the way down, and also from solar input. It is even possible to put additional load (stones or water) on the bicycle in order to generate more energy on the way down. In total, the required battery will probably be only 20% the size of a typical cargo bicycle, making this version cheaper and also requiring less battery replacement / maintenance costs.
(72) Dockless bicycle sharing system
While many other cities have this, Kathmandu and probably all other cities in Nepal does not yet have a dockless bicycle sharing system, or, in fact, any bicycle sharing system.
Since Kathmandu is not cycle-friendly at all, the bicycle sharing scheme should be complemented with a bicycle optimized navigation app (see the following idea for that, no. 73). All bicycles would come with a waterproof handlebar-mounted case where the user puts in their own smartphone to use as a navigation system. The case would also protect from direct sunlight.
(73) Cycling and walking navigation apps for Kathmandu
Kathmandu is not a cycle-friendly city, but one has to start somewhere if one were to make it cycle-friendly. It is quite ok to cycle in Kathmandu when knowing all the small streets and paths without heavy traffic (esp. without trucks), and when knowing when and where will be rush-hour traffic. For example, cycling at midnight in Kathmandu on the main roads is extremely fast, as there is neither traffic nor traffic lights or police guiding the traffic.
To benefit from this knowledge, there would be a special navigation app that guides the occasional cyclists through these small streets. That could be based on OsmAnd, the best open source map and navigation app for Android (see the licence details). All routing in that app is done offline, so data rates and mobile reception are not an issue.
The app would gather its cycling recommendations from its users, by asking users after a trip to rate its cycle-friendliness (perhaps split in sections, and allowing users to add a voice note).
The same principle can be applied to walking in Kathmandu: it is well walkable if you know where to walk to avoid air pollution, street noise etc… Finally, the same principle can be applied to other modes of transportation, such as roller blades, electric roller blades, foldable kickboards (electric or not), mixed mode transportation using a folding bicycle plus buses and taxis, etc…
The way to make a business from this idea would probably be to create and publish the software under open source licences, and then to offer setting up and maintaining the system to city administrations worldwide. That would include gathering the first routing information oneself, adding other routing information from traffic counters etc., and then start with community building so that users collect and update the routing information from then on. Still, the business will need to do quality checks, error fixes etc. on that data.
(74) Public transport routing system
Google (and others) provide public transport routing for many cities, but not for Kathmandu as there is no proper data source for timetables and routes, and anyway times are only very approximate.
This can be fixed by crowdsourcing the bus routes that exist, similar to how it’s done by Transport for Cairo. In addition, one can create an adaptive real-time routing system by attaching GPS trackers to the buses (hacked from a cheap, used smartphones and a big magnet). This will be more accurate and dependable than “timetables and the usual delays”, and means that there is no need at all to define timetables for Kathmandu and other cities in Nepal. Defined routes plus a realtime routing app is fine.
Again, like with the cycling and walking navigation apps (see idea 73), this idea can be made into a business by setting up the system and offering its setup and maintenance to city administrations worldwide.
(75) Novel bamboo furniture
Bamboo is a great material since it grows much faster than trees (6-8 m long timber bamboo is harvested at 6-9 years of age, small bamboo much earlier), is strong and versatile. Like wood, it can even be processed into multi-layer sheet material. And there are many more unexplored ways to use it:
This idea is about combining bamboo and (recycled) plastic into a flexible furniture construction system that also allows custom, made-to-order sizes.
Unlike traditional furniture, incorporating CNC-milled or 3D printed plastic elements allows to create furniture with moving parts. For example:
- foldable clothes drying stands
- clothes dryers that extend from the wall
- folding chairs
- camp beds in the style of the US Army folding cot (more images)
- standing desk with height-adjustable desk surface
CNC milling or 3D printing would be needed in order to produce the connecting plastic parts exactly for the inner and outer diameters of the bamboo tubes at hand.
(76) Nut and seed cheeses
This is really weird, but: it’s possible to make proper, tasty, aged, fermented cheese not just from animal milk but also from all kinds of nuts that have protein and fat. Even from stuff that grows in abundance wild and that usually nobody eats like (as an example from Europe) acorns. Not sure what the right raw material would be in Nepal, but there will be something. Maybe even the seeds of jackfruits (yes, you can eat them … google it … also, I tried it).
For sure, vegan-crazed tourists will love these cheeses. You could sell them, for example, to some of the vegan restaurants in Kathmandu.
Here are some links:
starter kits for nut cheese (shipped inside Europe)
webshop with six specialty nut cheeses and crazy prices
(77) Dry toilet system for cities
Flush toilet systems produce a big mess that as to be cleaned up again – as everyone who ever crossed over Bagmati river in Kathmandu can testify. However, dry toilet systems of various sorts slowly emerge as viable alternatives, and there is a lot of space for innovative public utility entrepreneurs here. Especially in countries that have no working sewage treatment systems, like Nepal.
A design of my own and a discussion of existing dry toilet systems in cities worldwide is here: “Dry toilet system for cities”.
(78) Healthy cooking stove
In Nepal, household air pollution due to the use of solid cooking fuels shortens the average lifespan by 15 months (source; but it’s even more for the 65% cooking this way in Nepal, because 15 months seems to be averaged over the whole population in South Asia).
This can be pretty much fixed by selling cooking stoves that do not let any smoke escape into the house – there is no need to persuade people to switch to a different (more expensive) cooking fuel like LPG or electricity. To the contrary, the improved stove can be made 30-50% more fuel efficient by integrating a heat sheath and insulation around the pot (source). If not health reasons, than the fuel savings should be a good argument to get such a stove.
Rough design proposal:
The pot should be embedded into the stove. This allows to route the hot air around it on the way to the exhaust, and to integrate insulation on the other side. This will lead to 30-50% savings in fuel costs.
It should be a rocket stove, as these are more fuel efficient and emit less smoke.
Chimney construction and stove construction should be carefully done to ensure that natural updraft prevents any smoke from exiting, even when refilling the stove.
(79) DIY indoor air filters
Air quality in Kathmandu valley is dismal but can be improved a lot on an individual level with HEPA air filters placed into the rooms of the house. Such filters are available as industrial products for 600-800 USD in India for example, but that is not affordable for the average city dweller. There is also no reason at all why they have to be that expensive. Full instructions for an effective air filter that more or less everyone can make are here. Alternatively, you could import and sell the simple but more industrially produced air filter based on the guy’s instructions and sold on Taobao as The Cannon for ca. 70 USD.
(80) Import used photovoltaics panels from Europe and USA
In both Europe and the USA, used photovoltaics panels are available in large quantities for purchase. They cost typcially about 30% of the brand-new price of modules with the same rated output, and they still work like new or with 10-15% less output due to degradation over time. The reason why they are sold so cheaply is because photovoltaics installations should be done with all panels of the same manufacturer and type, and used modules are not available in large enough quantities at the same time for the typical installations done in Europe or the USA these days.
On the other hand, photovoltaics panels are sold with exorbitant high prices in the small shops in Kathmandu (it was 200-300% the international average in 2015 when I last loked). And in villages, prices are probably even higher.
And in Nepal, especially in villages, people only need 1-2 panels (100-400 W) per household, which can totally be supplied from batches of used panels. So clearly, there is a business opportunity: let somebody in Europe or the USA collect PV panels until there is a full 20 ft ISO container of them, then ship the container to Kathmandu and sell the panels to PV panel shops all across the country. Also provide a direct outlet and a webshop, in order to force shops to drop their sales prices – otherwise, Nepali people would still not get to enjoy cheap clean energy.
In addition, there are special inverters that do away with the requirement that all panels have to be of the same type for an efficient installation (namely, SolarEdge inverters, due to their separate Power Optimizer devices). It’s just that people don’t know that these inverters can be used to make better use of used photovoltaics panels, but they can. You could import them to Nepal as well.
(81) Trans-himalayan farming
Trans-himalayan areas allow some farming; for example, Jumla and Mustang provide local apples to markets in Nepal. Production is however limited by water availability.
Here, water harvesting techniques known from desert areas can be employed. They can be combined with modern improvements – see here for a proposal that would increase the potential growing areas by nearly 600% due to an improved water harvesting technique:
(82) Trans-himalayan photovoltaics plants
This is certainly at least a slightly crazy idea, and may not be applicable in the next 5 years, but I am sure its time will come
Solar panels profit from the conditions provides by some trans-himalayan areas in Nepal:
- high solar irradiation, because the sky is mostly clear as the mountains keep away the clouds and the rain
- cold air temperatures year round due to the altitude, which improves the electrical efficiency of the PV panels (a PV cell temperature reduction of 20 °C leads to 9-12% more electricity generation – see here at p. 2 in the PDF)
- no disturbance of nature by use of area (because there is no vegetation in these areas anyway)
- no competition with agriculture / food production, or with land use for accommodation
- cheap land prices, as the land is basically unused
- some mountain slopes provide a 30° south inclination naturally, lowering the need for and costs of the sub-structure needed to hold the PV panels at the perfect angle
Due to the climatic conditions alone, the Himalayan region and Southern Andes region are the areas with the highest possible PV output per installed capacity worldwide, and the Himalayan region is the most interesting here:
The regions with the largest irradiation values have large PV potentials. In particular, the Himalaya and Southern Andes regions have energy potentials of more than 1800 kWh/kW PV, due to the combination of large irradiation values and low temperatures. The Himalayan region is especially attractive because it is near regions with large future energy demands, such as China and India. (source, p. 8 in the PDF)
This is confirmed by the Global Solar Atlas, an interactive map that shows solar potential worldwide, calculated with an inclusion of air temperature (see). It shows that Nepal has several sites with >2000 kWh·kWp-1·a-1, and that these are among the highest values worldwide. For comparison, PV yields in central Germany hover around half of this, making solar electrical generation twice as expensive there, and still it’s applied on a wide scale.
Creating a PV plant in such a remote area and connecting it to the national grid is quite a challenge, of course. It means that it makes only sense for large projects – but the space for large projects is easily available. For example, covering a a 2×2 km mountain slope with PV panels will be very roughly a 600 MW plant, which would already be among the largest worldwide.
You can use the Global Solar Atlas to find your perfect project location. My personal favourite so far is the mountain slope at
28.799668, 83.471674 (map, 3D view, Global Solar Atlas map). It has the following benefits:
- 2050 - 2080 kWh·kWp-1·a-1 expected solar yield
- 60-80 km from Pokhara, so the connection to the national grid is manageable
- 30° south inclination, allowing to install PV panels without expensive frame substructure
- quite smooth, vegetation free mountain slope, allowing a relatively easy installation
- not in a national park, to avoid issues with construction permits
For examples of existing PV installations at high altitudes, see here.
(83) Solar Power Panels with microgrid option
This is a product idea for a special type of photovoltaics panels that is especially suitable for villages without an electrical grid. Such a product can be produced locally inside the country, as it just needs normal solar panels, cables, electronic parts and some plastic parts (which can be 3D printed).
The following is the rather long and unsorted set of notes about this, which (for now) I just copy & paste here from my internal document:
Basic proposal and system layout
Every house gets one 40-50 W§ solar panel with charge controller and batteries attached to its back, called a “powerpanel”. This is sufficient for lighting, mobile phone charging, radio, and tablet computer use, also for notebook use and charging during the day. The battery should be LiIon or LiFeO4, in 18650 cells to be flat behind the panel. It will be suitable for 2,000 cycles by only cycling between 20 and 80%. Combining everything into one weatherproof device reduces breakage through bad cabling connections, water damage etc. in the house.
The only connections needed for powerpanels are cables into the house (both 12 V DC and 24 V DC are supplied, with 24 V DC preferred for lower losses) and optionally cables to neighbors (24 V DC or 48 V DC for lower losses, to be decided). Cables are attached in weatherproof manner without tools to the back of the panel, without a need to prepare cable ends (needs special clamps). Cables will be supplied locally, also additional lamps etc… Some LED lamps and mobile phone chargers will come with the powerpanel, though. Also a flashlight (headlight) with charger.
The status can be read from a special socket that includes a LCD with watt hours left in the battery (also as a bar diagram), and the estimated time until empty or charged based on current use or sun input. That socket will communicate with the powerpanel over SPI or a similar protocol, using the power wires. The socket also comes in an additional variant that allows to connect a smartphone or computer by Bluetooth or wifi, to read energy statistics and make configuration settings, but that is all optional. It is sufficient if a technicial has that device.
To scale the system, houses can install multiple powerpanels and connect them with the “to neighbors” lines while configuring the panels to know that both are of the same owner.
One special attribute of this system is that it forms a microgrid. Neighbors can help each other out with electricity, and the excess available at neighbors (in batteries during the night and also in production during the day) will also be shown in the special socket’s LCD.
Like any off-grid solar system, these installations will produce a lot of excess solar power. This might provide an interesting way of financing the system: it is installed in every home for free or for a very affordable price, in exchange for all the unused electricity. The unused electricity is then sold to businesses, as electricity or better in the form of useful services (water pumping, battery powertool renting station, grinding and threshing station, refrigeration container etc.). This might be provided as an outdoor 230 V AC electrical socket where people use coins (and / or smartphones) to pay for operating their machines from them. Only the “dependable” part is sold off this way (based on a weather forecast), while the rest goes to non-critical consumers like a refrigerator with a large thermal battery (“ice block”), or water pumping to an uphill storage area.
A typical solar potential in the Nepali midhills is 1500 kWh/kW§ per year, see http://globalsolaratlas.info/?c=28.076827,85.286865,8&s=27.931327,85.14679 . So 4.16 kWh/kW§ per day on average. A village with 500 houses with a 50 W§ panel each has 25 kW§ installed capacity, so 4.16 kWh/kW§ * 25 kW§ = 104.16 kWh/d on average. Of these, 44.16 kWh might be used during an average day (88 Wh per house, enough for three full phones or tablets and 50 Wh lighting). So on an average day, 60 kWh/d are available for free, of which maybe 45 kWh are usable due to line and conversion losses. This is enough for (for example) 5 water pumps of 2 kW each running for 4.5 hours each.
To minimize line losses even in dispersed villages, several 48 V DC trunk lines would be installed, and all houses would connect to these (not directly to their neighbors). And there would be several usage points in one village for the “commercial electricity”, not just one. Using such “trunks” has also the advantage that individual powerpanels do not need to “route through” any energy – they need only a DC-DC controller strong enough to put its own output “on the grid”, at the grid’s voltage of 48 V DC.
Even better and simpler, there should be 48 V DC lines throughout the house as well, so that the powerpanel needs only one DC-DC converter for its output, to the house and grid combined. Then in the house, sockets will have step-down converters, and might even be switchable between 6, 12 (rather 15) and 24 (rather 28) V DC. Just not by end users, as that will lead to broken equipment. This way, thinner and cheaper cables can be used. Only operating high-powered tools is not possible, but this is not planned either. If a 500 W powertool would be used, it would be a battery-operated one anyway. These DC-DC converters would be switched off if no load is connected, saving the standby power use. An additional advantage of this setup is that traditional fuses / fuseboxes are not necessary (except for one main fuse in the powerpanel). Because DC-DC converters will regulate the down in case their current rating is exceeded, if necessary down to zero in case of a short. This reduces maintenance effort and improves reliability (no need to find the triggered fuse etc.), and also improves safety as the down-regulation is instantaneous and not depending on tens of seconds of overload as in the case of thermal fuses.
This setup seems very sufficient, as it will take a long time until households add more consumers (probably powertools at first, which can be charged with the current setup without issues, esp. by utilizing excess electricity from neighbors).
The powermodule box should not be integrateable with the PV panel, but mountable to its back. This allows to upgrade existing PV panels (cutting system costs by 40%) and also to utilize 60-70% cheaper second hand PV panels of all kinds of different sizes and types.
Instead of powerline communications (or network cables or drilled two-wire with ADSL etc.) between powerpanels, long-range wifi would be used, together with the Guifi architecture. This has the lowest capital costs and maintenance requirements, and is sufficient for both the communications necessary in the microgrid and for providing Internet. Since powerpanels will typically be mounted on a rooftop or pole, they are already in the right place to add the wifi antenna.
Grid voltage, home voltage and grid connection
Discussion of the grid voltage, home voltage and grid connection (resulting in 60 V DC for the grid and 24 V DC for the home, see at the end):
The energy routing functionality can be with or without a permanent grid connection. With it, a dynamic equilibrium of “zero current to / from grid” would be maintained except an import or export has been negotiated. This needs DC-DC converters with current limiting for the battery output so that it only supplies as much as the house needs (while the charge controller only supplies the battery). This means two DC-DC converter even for using electricity in-house, which is a waste. Also, regulation is more tricky, and the setup feels “dependent”.
Instead, there should not be a permanent grid connection (and having it is even optional). There would be one DC-DC converter with current limiting at the grid interconnection. Normally, it is disconnected with a MOSFET (not using any energy in standby). If the powerpanel negotiated an import or export from teh grid, it will be configured and connected in the right direction, with the right current limit as negotiated. In order to take electricity from the grid or put it on the grid, the powerpanel first has to negotiate with other grid devices how much and from whom, using the long-range wifi network. In the case of exporting, it then has to fulfill this “contract”, if necessary even by using its own internal battery in case that short-term solar fluctuations do not allow generating enough energy on the fly. This makes the grid dependable for all consumers and uses the batteries of all connected devices for “distributed grid stabilization”. Contracts would usually be short (2-10 minutes), so the load on the batteries is low. Longer contracts would be paid better as there is a higher “risk” for the provider that he might need more expensive battery electricity to fulfill it.
This setup also allows to create the powerpanel device by combining off-the-shelf components, as no charge controller with current limiting is required. Instead, just a normal charge controller, a DC-DC converter, a Raspberry Pi computer etc…
However, a hybrid solution between grid connected and not is possible and even better. To decouple the battery voltage from the grid voltage (allowing to use normal 12 / 24 V charge controllers not rare 48 V ones), charge controller and battery should be in a 12 V section (given that small solar panels are always for 12 V anyway, operated at 15 - 18 V DC). Then, there is one DC-DC converter that can supply consumers both in the house and in the grid, with a relay or MOSFET to cut off the grid connection (which is the normal case, so there is no need to keep a dynamic equilibrium normally). When there is an import or export contract with the grid, the current limit of the DC-DC converter is adapted dynamically to keep within these limits.
The problem with this setup is the conversion waste: 18 V (solar panel output) → 12 V or 24 V (charge controller output) → 48 V (grid and house) → 12 V (consumption points in the house, mostly). At 95% efficiency of DC-DC converters and three conversions, this means 86% total conversion efficiency. Obviously, with a 48 V battery and a special (open source) charge controller for that, this can be reduced to two conversions, resulting in 90.25% conversion efficiency. This is as good as it gets, since LED lamps, DC adapters for notebooks and USB charging etc. use an integrated DC-DC converter anyway, even if the grid voltage would be 12 V DC. So it’s better to provide versions that convert directly from 48 V DC, as that has 16 times lower line losses than 12 V DC. However, having that third conversion also makes sense as it keeps the grid voltage stable, isolated from the fluctuations of battery voltage. Obviously, it also limits the load to what the DC-DC converter can supply, but that is also an integrated safety feature.
Further efficiency improvements would be possible with 48 V consumers in the house, but these are not really available.
So in effect, the best seems to be to rather split the voltages between 60 V DC in the grid (highest “safe” DC voltage everywhere worldwide, see https://en.wikipedia.org/wiki/Extra-low_voltage) and 24 V in the house (allowing to use 24 V DC fridges etc. and having acceptable line losses, 4 times lower than 12 V DC). And then also to use a 24 V battery, accepting slightly fluctuating voltages in the house (but not in the grid). The small 12 V panels can still be used, as there is a MPPT conversion from panel to battery anyway, and conversion efficiency is not much influenced by the voltage step. This way, there is ideally only one conversion from panels to battery voltage (but not later from battery to consumers). Efficiency is obviously more important for larger loads – this is the case if large loads are 24 V DC, such as a 24 V DC fridge. A 24 V house voltage has the additional advantage that the battery is directly connected to consumers, allowing higher loads (500 W for powertools) and then recharging the battery quickly from the grid if necessary. Also, 24 V powertools are available, and 18 V etc. powertools can easily be operated at 24 V by using PWM current limiting.
A bidirectional DC-DC converter with current limiting can provide the required connection to the grid, such as one using split-pi topology (https://en.wikipedia.org/wiki/Split-pi_topology).
Grid to battery connection
The grid DC-DC converter would always connect the grid to the battery, either potentially charging it (when importing and not all is used by current loads) or potentially discharging it (when current production is not enough to meet the current load and current contracted export). Obviously, that requires the DC-DC converter to have a variable output, as it may have to act as a charge controller. Not as a MPPT controller though, which limits its complexity.
When importing the DC-DC converter can not be connected to the panel side (to save the second charge controller logic). It would confuse the MPPT controller’s regulation if this power source provides a constant voltage as long as it is within the contract conditions, and then that voltage suddenly goes to zero when hitting the limit of the current power import contract. Also, such a setup would reduce the efficiency by having two DC-DC conversions in series.
When exporting, it seems not practical either to connect the grid DC-DC converter’s input directly to the solar panels. This would increase efficiency by eliminating one of two DC-DC conversion steps. But it adds complexity as the DC-DC controller now needs to include a MPPT controller, and (worse) when the PV module’s production is not sufficient for the current demand of the export, additional input would have to come from the battery somehow. The simplest solution is to keep the DC-DC controller permanently connected to the battery, as in the original proposal above. Electricity exported to the grid is typically “excess power” anyway, so increasing the efficiency when exporting is not important.
Solving the DC grid management problem
An advantage of this setup where there is no direct access of electrical consumers to the grid is that it solves the task of DC grid management (which is normally difficult because no AC power factor can be utilized to direct currents to specific loops in a grid).
In the DC grid, current will only flow after a contract has been negotiated, and that contract’s limit will be electrically safe (respecting maximum currents for all sections in the grid, due to cable diameters). In a meshed grid, it will still be difficult to know before where currents will flow when adding an additional source and load. But the distribution of currents over the different routes between two points can be tested (with small currents) when only this one source and one load exist in the grid. This test can be done regularly for every connection of two points (to account for varying resistance of wire connections etc.), for example by reserving the first 20 minutes every morning for testing so that each combination of source and load is tested every month. Line losses between each two points would also be tested at the same time. The test results are then saved and used when negotiating contracts.
Note that adding a new contract may involve modifying existing ones, as some current flows will cancel each other out, and limits might have to be adapted. For example, when observing that an existing contract did never utilize its maximum power transfer capacity but that maximum prevents another contract from being added, that limit could be automatically re-negotiated.
Miscellanea issues and remarks
Now the issue with a 60 V DC grid is how to use that energy efficiently. Battery powertools with PWM current limiting can be used. 60 V DC motors for pumps etc. are widely available. In cases where high-power 230 V AC electricity is desired, installing a large inverter is not a good idea as it costs a lot and is not user-repairable when it breaks. However, a motor-generator can be used as a DIY solution, see https://en.wikipedia.org/wiki/Motor–generator . Efficiency is here less of a concern, as this is “excess” electricity anyway.
There will be a Raspberry Pi device inside the powerpanel, taking on all communication and regulation functions. It will have wifi (for the house), an additional long-range wifi adapter connected via USB (for external communications and Internet access), SPI (for communications over power cables in the house to sockets and devices). Because there is always a wifi device in the powerpanel, its configuration interface can be provided as an app / local website.
It is possible to use a compressor fridge even with only a small battery, if it is a custom (open source) model using an ice block or similar for cold storage, and fan for circulating the cold air when it is needed. Then, the fridge will only consume energy when the sun is out, not from the battery.
Note that with a 60 V DC grid, all kinds of other generation equipment can also contribute electricity when needed, for example combustion engines connected to biogas (or biogas plus hydrogen) plants, micro-hydro power stations, wind power stations etc… It is ok for these devices to not use current limiting at the source if they are ok to perhaps provide more than contracted (that is, some electricity for free). Current limiting is expensive at higher power, as it needs a DC-DC conversion (PWM current limiting is not applicable here as the grid expects continuous current always).
One of these power panels can also be used for each solar streetlight. (Even though this should be avoided as much as possible, to prevent light pollution.) The streetlight would be 7-10 W permanent and 40 W on demand when motion is detected.
A nice property of this proposal is that “very standard” 250 V 16 A cables (1.5 mm² cross-section resp. 15 AWG) can be used to connect houses to the larger trunk lines. So basically, normal household extension cords. With a good waterproof way of interconnection, it will be possible to just connect several available pieces of cable. The line losses are acceptable: such a cable will lose at most 8.9% of transported energy, for the assumed maximum distance of 300 m, at 60 V and 0.85 A maximum current, corresponding to 51 W exported energy. See this voltage drop calculation.
Such a cable, in the cheapest version that is ok for outdoor use (when protected from direct sun) is ca. 0.50 EUR/m, see https://www.ebay.de/itm/252980614323 . 2x1.5 mm² cable is not cheaper (usually 20% more expensive), as it is more rare. It may be possible to use the third wire for communications of some sort. Also 4×0.75mm² can be used, but is also more expensive (ca. 0.75 EUR/m).
Still, a house that is 300 m from its neighbor would pay 150 EUR for the cabling, about as much as for the whole rest of the installation. That will probably not pay off. Which means that houses will connect with others if they are within 100 m of their next neighbor. This will result in several “islands” within villages, and a commercial operator that intends to buy the excess electricity from the houses would maybe undertake the task to connect some islands together.
Cable voltages would be negotiated to be higher in order to have 60 V DC at the large consumer (exact voltages are not relevant at all for all houses, as they have a DC-DC converter and can work with any input voltage, but the large consumer of excess power has none as such a thing would be too expensive). As long as the voltage is kept within safe limits (75 V DC for the EU, 120 V DC for other countries), there are no issues with this approach.
(84) Plastic sorter for plastic recycling
A small machine or set of machines for washing, sorting, shredding and perhaps pelletizing plastic trash. The resulting materials can then be sold to other small-scale entrepreneurs, or to large commercial recycling operations. The business idea is is however to produce the sorting equipment, which canthen be used by other entrepreneurs in cities throughout Nepal.
The machines do not have to be fully automated. Trained humans are also good at recognizing plastic materials, as different products are typically made of different typical plastics.
(85) Soil production from street dust
For example in Kathmandu, several tons of dust can be swept from the streets every day – the city started doing this in early 2019 using six street broomer machines, but so far they only deposit the dust, to be trucked to the city’s usual trash dump.
Instead, the street dust could be taken from there and converted back into soil – because it is actually fertile soil that was blow away somewhere else.
Of course, the collected dust must be properly cleaned before being used as soil for planting. At minimum, the contained plastic trash and other debris has to be removed with a sieve. Then, the collected dust would be mixed with compost to create proper soil. Afterwards, it would have to be stored long enough (2-3 years) for hazardous germs inside it to die off through competition with soil organisms. During that time, hazardous substances like heavy metals can be extracted (if the soil contains any) by letting water seep through repeatedly and filtering it, and / or with hyperaccumulator plants.
(86) Swale construction
Swales (artificial contourline trenches on sloped land) are a simple technique to increase the groundwater table through rainwater infiltration. This can be very useful in Nepal, which has too much water in a part of the year and too little water in the rest of the year. The increased rainwater infiltration would result in new springs and increased spring flow, which can then be used for irrigation purposes.
The business idea here is to offer swale construction to villages and groups of farmers. The farmers can do the actual digging work, but the consultant would create a plan, provide measuring instruments etc…
Other mechanisms for rainwater infiltration can be added to the portfolio as well, but swales seem especially adapted to terraced land.
(86) Landfill recycling
There are multiple recycling related ideas in this list already, and here is one more, probably the most extreme one:
Landfills are full of recyclable materials. So a company could negotiate free access to a landfill site and set up equipment that allows to dig up landfilled trash and recycle it. Probably, one would use trash that has been in the landfill for multiple years already, as most of the hazardous germs inside it will have died then.
The goal is to sort and re-use everything:
- sort out individual items that can be upcycled (mirrors, nice glasses, kitchenware, metal objects etc.)
- sort, shred and pelletize the plastic; burn the plastic (safely) that cannot be reasonably recycled into anything else
- shred and pelletize the wood as fuel
- sort and shred the metal parts
- compost the organic trash and sell the soil (techniques for removing hazardous substances may be needed, see at “(85) Soil production from street dust”)
- send the electronic components to professional recycling plants; the plastic parts, PCBs etc. would be removed before, reducing the weight and volume by >90%
The issue to solve is how to provide a safe and comfortable working environment efficiently. 20 ft ISO containers can be put up on-site, with workers on both sides of a conveyor. The conveyor would be covered from the sides and top under glass and workers would reach in through manipulators (holes with strong, safe gloves attached to them). The whole container would be filled with air under a slight overpressure so that no stinky air can get inside, and the air in the container would be constantly pumped in from 400 - 1000 m away from a location where there is no smell of the trash dump. After sorting and washing, the materials would be trucked away to other more specialized companies doing the other steps of the recycling process.