PV Gap

Milton Said:

how can you make homemade solar cells?

We Answered:

You can make solar cells in your kitchen, according to this article:

http://www.instructables.com/id/My-home-…

You can put cells in series for more voltage and in parallel for more current.

I didn't go through this article, but I doubt it is even close to practical for home power generation.

Jessica Said:

homemade solar cells?

We Answered:

The only home-brew solar cells that I know will work are of the copper oxide type. Try the site below or do a search on "CuO solar cells":

Bradley Said:

How environmentally friendly are solar cells *really*?

We Answered:

Rich, your researcher friend working for the military is off target for two reasons, I'll explain. What you are referring to is the, "Embodied Energy," in a solar panel. It is the total amount of energy used to dig up raw materials, ship to the plant, make the product, ship to the user point, and install. Obviously it is a bit difficult to quantify exactly, but several studies were done in the 90s about this subject, probably the best work was done by Solar Energy International, a non profit group that does research and education on the subject. Most commercially manufactured solar panels in the US have a range of embodied energy that would take between 1.5 and 6 years for the panel to earn back in normal use. Virtually all panels available today are warrantied for 25 years, and most work well beyond this time frame. But in the end, none of this matters, here's why:

Electricity has been around for over a century now, and each year we find newer and more exciting things to do with it, so it isn't going away anytime soon. The question becomes, "What is the best way to produce it?" Let's assume you take a 250 watt solar panel and put it alongside a highly efficient conventional power source, like a natural gas fired turbine generator that also produces 250 watts at peak power. Which device will earn back it's embodied energy faster. The answer is the gas fired turbine never does. You have to remember that no matter how small the embodied energy is in the turbine, once you build it and install it, it now has to be fed natural gas for the rest of it's life, and then it converts that fuel to electricity at an efficiency rate something less than 100%. So the turbine simply keeps digging itself a deeper and deeper energy hole that it can never crawl out of. At least the panel has a chance to get even some day. The discussion is the same when comparing any conventional power source, such as a coal, oil or gas power plant to anything renewable, such as a solar panel, wind turbine or hydro plant, the numbers are just a bit different.

This is the real reason that the drive to renewable has gotten so much steam built up lately, we can finally see all these technologies for what they are. Were you around 30 years ago when we were still arguing about whether cigarette smoking was bad for your health? Can you find anyone still willing to carry that argument? Imagine 30 years from now what people will be saying about burning coal to make an airconditioner run.

Hope this adds a little horse power to your next discussion. I'm curious, what does a military "researcher," research exactly? I don't think they are in the energy business anywhere. Good luck, and take care, Rudydoo