There are many places the public can buy fuel cells. The problem is, the general public can't afford them, and it probably isn't worth the effort for most people.

Re: Mmm... solar
 

I hate to push the point but my calculator makes 70 watts translate to 5.83 amps at max illumination. It would make a great battery charger being right in the specification for charge current. All things being equal though, you still have to get an array that can handle both high current and at least 12 volts and still in the package size that can be fit on the robot. That is still a difficult thing to do.

microwave
 

i was thinking of using a high power dierctnoal Microwave transmiter and beaming power directly to our bot

I just read an article that the best efficency is 20 percent for a silicon solar cell.
Oooo yeah I found the fuel cell kit. It is pretty cool.
http://store.yahoo.com/discoverthis/fuelcelcaran.html

No.

???????????? What is this no in relation to??????????

You shouldn't be so quick to assume. While it's not a probable idea looking at the competitions so far, there's no reason the people at FIRST couldn't get crazy and switch things up a bit one year. FIRST won't necessarily always be stuck in on a rectangular field inside a (makeshift) arena. There's no reason why things always have to be the way they are now. I'm just saying... this is only my (hopeful) opinion.

My reasons are the same as the ones of the people who've already responded. During the winter, it's hard to have sunlight to test the robot, especially in my town, one of the cloudiest in the USA. Also, competitions would vary too much from place to place due to sunlight. The problem with it is that it's just not a form of energy that we can fully monitor and control.

I was at the NE solar sprint championship a few years ago and I did very well. Picked up a couple trophies but that was quite lucky. I saw good cars go slow and vice versa. Not because they were bad or good but because they just performed erratically with the clouds overhead. There's way too many uncertainties and variables to test.

I helped build a solar boat in one of the classes at our High School. We used 4 huge solar panels which at max would give us 12 volts @ 48 amps. That is in lots of sunlight.. normally we would max at around 30 amps.

This is not enough to really deliver power to the robot. Now if batteries were used, as we didn't it would have been a different for us.

The solar panels were about 2 x 3 feet, and weighed about 20 pounds each.

There is really no physically possible way to use solar power on these... unless you use 1 to power a battery, and it bright sun light.

You could have solar panels charge your batteries out in the pits, if you are outside.

Another point is that if the solar panels are not VERY WELL protected (which'll require weight ... and probably lots of it), the damages would cost way too much to replace over and over. So the overall weight of the robot would have to be increased and that would mean you could potentially have heavier objects travelling in excess of 10mph at walls and field barriers.

Re: Re: Mmm... solar
 

I never said it would be easy!! :)

The robots would be alot different... but I've been to solar robotics competitions. Makes FIRST look like a gas guzzling SUV compaired to a nice efficient hybrid. Alot of waiting to change the caps, but we call it suspense!

Also, I need to correct myself... I said there had been experimental cells up to 40%.... OK, I can't find that press release. But cells OVER 30% do exist...

But I should also point out these people arn't screwing around with silicon either. You can't pick up gallium indium phosphide on gallium arsenide cells at your local hardware store. Any they are using more than the sun. (There are some efficiency gains to having specific wavelenghts and lots of light.)
1999 NREL press release

NREL again for you multi material, multi layer type PVs.