Very Small Scale Power Generation in Developing World Answered
I volunteer for a non-profit which distributes solar lanterns primarily to students as well as people who are in need of the lights. Things have been going well but a lot of people have inquired about us providing access to a higher powered version for various reasons and we've noticed that some households go back to their old ways when the lanterns don't receive enough sun during the day.
Temporarily we are solving the problem by having local entrepreneurs charge batteries for the families for a small fee but we feel that this should not be a permanent solution. It's not the price that's the issue it's that sometimes the people have to walk for a number of kilometers to get to the nearest charging station or have to cross dangerous terrain (I have personally experienced this).
Over the last 3 years we have helped over 5000 families by giving them solar lights so we would like to modify all those units to have more stable energy generation. Our current version has an output of 5 watts. We are looking to buy or build a unit which produces a maximum 8wh an hour until the fuel source runs out or something that can generate in a more slower rate such as 40wh in 16 hours so we can let it run overnight and have the power stored in a battery.
We are primarily a donation driven group so something with low cost and maintenance would be really great. We highly subsidize the price to a large percentage of the households but we also provide them free for the lowest 10% of households who can't even afford the lowered price.
I personally think that something which can generate electricity from hydrocarbons due to their high energy density and easy access would be ideal but I'm not an engineer so what do I know. I'm not sure if this helps in any way but a number of years ago we transitioned a large number of houses from wood fired stoves to gas and as all the families that we help actually have access to gas I was wondering if any good technology exists where electricity can be generated by gas that can meet the low cost and maintenance criteria. I've looked into thermoelectric generators but they are really inefficient and people will be wasting money to heat their house in a country where average temperatures are in the 30'sC
I also see a future issue regarding battery degradation as we use small lead acid batteries and while thinking of a way to solve this I came up with the following idea and is one of the reasons that I'm posting on instructables.
What if a pedal powered flywheel generator was built with a 200W generating capacity and 40Wh worth of 'storage'. When you pedal you will spin up the flywheel and it will store the energy until you need the electricity again and we could also wire up the solar panel that we already use to spin up the flywheel. So when the sun is out the panel is used and on rainy days and during the night you pedal for a couple of minutes for one hour of lights. If the flywheel can store the energy for a number of hours then someone could pedal for a couple of minutes at a time throughout the day and not have to do it at night.
This is just an idea that I came up with and if anyone has any ideas I'll be really interested in knowing about it (obviously the above solution is not ideal because they have to put some work into generation but it's the best that I can do). I've quite recently been looking into different types of fuel cells powered by m/ethanol and others like solid oxide cells and they seem interesting (does anyone here have any experience in building these type of cells?). This community has a lot of intelligent members who think outside the box so I'm confident that we can come up with something.
This ended up being a bit longer than expected and if you've read this far, thank you.
I wasn't sure about what section to post this in, square peg is the one I chose out of 5 so if this is wrong please feel free to move it to the correct section.
Help and advice will be very much appreciated.