I want to make an engine. I don't care what kind, as long as I can build it with simple tools and very little money. I am looking for any kind of engine, but what I am looking for is a good storage medium that I can transfer and then release energy from. Does anybody have any ideas or past luck?

 

p.s. the whole point is for it to be powerful, such as powering a scooter

What kind of power source do you have?

I don't want to use a battery, so that is sort of what I am looking for; I need a good storage medium that I could use to release energy into some kind of engine. I was thinking about using solar panels or just rechargeable batteries or anything safe to produce the HHO but I don't know how possible it would be for me to make an engine for that.

if you want to avoid batteries, and I guess internal combustion is not acceptable (otherwise you wouldn't be asking); solar will work but I believe it would be an expensive build and you would have to lose weight everywhere, for a short distance you could use a flywheel to store energy (after spinning it up using some interesting energy source), and if you love engineering and want a silly build - what about steam/compressed gas? And, if by HHO you mean the electrolysis products of water, be ridiculously careful; hydrogen is not easy to store - it tends to leak. maybe give the board more of an idea of what your project is - and you will surely get some suggestions