tycon69 said:
So one of my friends has some crazy idea for a science fair project and wants me to do a team project with him. He wants to make a small toy car that runs from hydrogen produced by hydrolysis harnessing electrical power from a solar panel...
It's theoretically possible, but the problem is that it would probably be significantly less efficient than if you just drove some electric motors from the solar panel directly (but solar cars have been built for science fair projects a million times). How are you planning to harness the hydrogen once you've made it, a fuel cell?
tycon69 said:
...and possibly wind turbines on the car.
That cannot work because it would be a prepetual pachine. You would be using wind turbines to capture energy from the car, only to put that energy back into the car minus any losses you have from the process. Basically the turbines would only net a less efficient vehicle.
tycon69 said:
Could the solar panel really make enough electricity to make enough hydrogen to run the car? Can we cram enough stuff into a model car for this to work?
While it is in theory possible (as long as the solar panels are big enough), the problem I see is that electrolysis is a relatively inefficient process. If you want the vehicle to be as effcient as possible, you will want to minimize the number of energy conversion steps you are utilizing. Right now you're talking about converting energy in the following steps:
1) Solar ->
Electrical
2) Electrical -> Stored Hyrdogen
3) Stored Hydrogen -> Electrical (I assume)
4)
Electrical -> Mechanical
Note that the first and fourth steps are compatible with each other, so technically 2 and 3 aren't
really required. As a proof of concept it is possible though, albeit with significant efficiency losses in steps 2 and 3.
tycon69 said:
Our science teacher, says that we could make an attempt and if it doesn't work that could simply be the result of the experiment, but i don't want to invest too much time in something that will not work.
You teacher is correct in saying that your scientific experiment could fail and still be valid, that's the nature of the scientific method. However I'm not sure that building a vehicle that uses solar energy to perform electrolysis on water which will then be run through a hydrogen fuel cell is necessarily a "scientific experiment," it's more of a combined application of many technologies together.
tycon69 said:
So what do you guys think? Is this a plausible idea? Could we do this in 3 months? Do we as high school students have sufficient access to the materials and knowledge required to build this? Money isn't a problem as a local hardware store will sponsor us if we present them with a good enough plan.
The plan overall is plausible (minus the wind turbines) and could work as long as you try to minimize the losses in your system. 3 months isn't very long, you'd better get started!