Solar Power?
 

Does any one think that it is possible to run a robot off of solor power and, if it is will first use it in the future as a power sorce?

NO and NO!
The lighting in most venues don't give you much in the way of available power (and they vary greatly in color output) and in winter in most parts of the US you won't be able to run the competition outside where it might work. Even using solar to recharge the batteries would require a large array to get any significant current vs. time for the batteries we use. (remember 4- 6 amps for several hours per battery depending on discharge state)

I agree...

Yes it is possible and no First will not use it as a future power source. It is just too annoying to use in a bigger robot. Unless you want to see robots moving at a slow rate then I solar power is not the way to go.

I think we'll sooner see fuel cell powered robots than solar powered one's... solar technology just doesn't have a large enough energy density yet...

Fuel cells are still a few years coming... they have methanol powered fuel cells approaching 35% efficiencies, but they can't produce large amounts of current.

Thanks for the replies. I was just wandering if it was possible.

Errr.... You do know that fuel cell technology is all ready being used in cars today. In fact they are being leased in Japan and California for government use.

i think that a solar powered game would be an interesting idea. mind u we'd have to make sure we always had good weather, or maybe that would be part of the challenge... solar power certainly presents an interesting idea of how we can work with science and technology though. gives u something to think about...

It is possible but really just not fun to watch. All you would need is
a)A bunch of sollar cells
b) Loads of capicators
c)A sollar engine or some device that can dump the energy from the capicators when they are full
It would be very boring though at such a large scale. Try searching for Beam robotics for more information.

!?!?

I think you mean batteries. Capacitors can't make the current density needed. If anyone is interested in yet another competition (solar that is!) try here...
http://www.formulasun.org/asc/
For the American Solar Challenge.

Hydrogen-based fuel cells are far too bulky with their storage systems. Smaller fuel cells will be needed for anything decently portable for use on a robot.

I've been looking into using Direct Methanol Fuel Cells for a personal project of mine. Size isn't much of a problem. There are a few companies developing some to replace laptop batteries, with longer running time and a quicker recharge. Though currently, they're bigger than most laptop batteries.

Of course, this technology is still pretty new, as far as consumer devices go, and is still quite expensive, so I don't see them as a power source for FIRST robots in the near future. Still though, it's interesting technology.

Anybody have any information on some cheap DMFCs to try out?

Perhaps he should have said "Fuel cells for public use" are a few years away.

Japan and California's governments won't really help the FIRST competition soon.

Mmm... solar
 

It seems to me people fear solar power...

Yes you can make a robot run on solar power. Like the ones I built sitting on my kitchen table. Check some BEAM robots out.

No I don't think first will use them. Low power density. Plus, the lights would have to be the correct wavelenght for the cells selected, which would also get expensive. (Different types of cells work better around different wavelengths)

But have faith people.... The energy from the sun at 12:00 noon in Arizona in July can reach 1000 W/m^2. (Here in detroit on a sunny day in the summer it's about 550 W/m^2)

Depending on the type of photovoltaic cell you use, you can get different efficiency. Most crappy terrestial cells give you around 8-12%. But there have been "special" (read: expensive) cells that have gone over 40% efficiency.

by the way... just for fun...
36" by 30" = .70m^2
At 10% eff off of 1000 W/m^2 you would get roughly 70 W.
Of course, everyone would have to wear sunscreen, sun glasses, hats, long pants and sleaves for fear of burning... And we would have to watch the robots for melting...

Oh..... one last thing.... you don't need batteries to store energy. Capacites have come a long way, baby. The Beam bots use regular caps, hybrid electrics can and do use ultra-caps and caps made with aerogels.

Sorry - I've spent some time with my friend, the photovoltaic.

I remeber a place where you could obtain fuel cells but I do not remeber the website.

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.