Science Buddies: "Ask an Expert"

I am trying to see whether or not using ultraviolet and infrared filters in front of solar cells will generate more energy output. However, when I showed my research proposal to some high school seniors, some seniors thought my idea was absolute crap. Should I go with this idea or try to come up with another idea?

I'd also wonder what the science is behind your hypothesis. Filters simply remove different wavelengths from the light. For your experiment to be successful you'd have to have some reason to think that removing the UV (or all but the UV, depending on your UV filter) would improve the output of a cell. Electrical (PV) solar cells are designed to operate in full sunlight and use as many wavelengths as possible.

You might want to do some research into the spectral response of PV cells and then I think you'll be able to answer your own question. It's not really a hard experiment to try if you use small cells and small filters, but I don't expect you'll see the results you want.

Here's a few websites i found that you might use to start your research:
http://www.pveducation.org/pvcdrom/sola ... l-response
http://www.makeitsolar.com/science-fair ... -light.htm

Hi, thanks for your feedback!

I actually have another project idea, but my mentor told me that the judges at a science fair wouldn't be impressed.

My idea was to have dry ice (in a container of sorts) behind a solar panel (standing up), and to have PV pipes lead the dry ice fog away from the solar panel. Ideally, this is supposed to cool the solar cells, and to prevent potential overheating of the materials inside. Is this a good idea?

I haven't worked with dry ice specifically. There is a lot of information available on the web about it though. The fog you're talking about happens when you drop dry ice in hot water. As long as the water stays above 50F the container will emit water vapor 'fog'.

I can't find anything that suggests the fog is actually cold or has significant heat capacity to absorb heat from the cells. What would be true though is that you'd be flooding the cells with water vapor which doesn't sound like a good idea. Unless I'm misunderstanding your idea?

Take a look at http://www.dryiceinfo.com/fog.htm to see how the fog is formed. Obviously putting dry ice (anything that cold) directly near the cells wouldn't be a great idea either, so I guess I can't suggest a great way of using dry ice to cool cells. I don't think flooding them with clouds of water vapor seems like an ideal solution.

They do water cool cells by putting tubes up against the cells and running chilled water through them. If you're interested in exploring ways of cooling cells, maybe there's a variation of that which will be an improvement?

Hi again,
So I was reading up on using water to cool solar panels, and apparently there is a cooling method where water is directly sprayed onto the solar panel. Also, I read that radiation damages solar cells? (please correct me if I'm wrong, this is the link I got it from: https://www.spenvis.oma.be/help/backgro ... oldam.html)

Going from there, I saw a user on a different forum state that Ultrapure water, or UPW, is used in nuclear power plants because of its ability to absorb radiation so well (again, please correct me if I'm wrong, I can't exactly find a reliable website on this). From this information, do you think it would be possible if I could test the difference between using UPW and regular water to cool the solar panel (directly pour onto solar panel)??

I wasn't aware that they flood water directly over cells. I'm not directly in the PV solar panel business so it was news to me.

UPW is something that you can't buy. It's water so extremely purified that it contains *nothing* except water molecules. You can't transport it easily because it would absorb gases and other materials. Companies that use it will make their own filtration plants to filter it as they need it. That equipment might be hard to get and is likely to be expensive. If you can find some or you can convince a company to let you get access to a filter, then maybe you can run that test. Getting your hands on a supply of the water may be your biggest challenge. Otherwise, it sounds like a reasonable test to try. I wouldn't expect it to make a lot of difference but perhaps the extreme purity of the water might minimize any damage to the cells. That's just a guess.