Sounds good. The cost is lower than I imagined, and it doesn't seem like weight would be too much of a problem. As far as branding goes, foreign travelers are are probably the predominant customer for taxis, so anything that gets their attention would work- maybe even as simple as, "This Tuk Tuk Runs on Vegetable Oil." That way they'll want to take a picture, ride, and tip nicely.
I agree with this. The real question is: would the fund yield enough of a return to justify investment? If you're investing, your goal is to get a return, and even if millennials are more environmentally conscious, I'm not sure that will change.
The challenge with a lot of "green" products, systems, etc. is that renewable/sustainable status isn't that compelling of a benefit from the mass market consumer point of view. I don't think standard societal behavior can be changed massively based on technology that is good just because it is green.
The key to success in transitioning to renewable energy will be bringing benefits beyond, "This product/company in environmentally conscious." Why are solar panels great? Because they utilize renewable energy AND save a homeowner money. Why do I want to buy a Tesla Model S? Because it doesn't use fossil fuels AND I never, ever, ever have to pay for gas again. If we're thinking of ways to make a rapid transition to renewable energy, we have to keep in mind that at some point the average Joe is going to make a purchase, either with money or his time, and the product/service/system should provide more than one benefit.
Might it be better to have the keyboard typing (help) power the computer itself, or at least nearby electronics? You lose energy as the distance increases, because it takes energy to move a current through electrical resistance.