Solar Panels

[lightoftruth]

How large a surface area would you have to have if you wanted to use solar panels to produce a voltage of 12V

Could you decrease the surface area by using concave mirrors or magnifaction glass to focus the heat etc

[cyclone]

You can get 12v solar panels which are pretty small, probably about the size of your keyboard, but they don't supply a verh high current (probably less than 1 amp).

There are much larger ones which can supply a higher amperage at 12v aswell.

[buildersmate]

As cyclone says, many single solar panels being produced do have a 12V output - for example Sharp do one. Some are 24V output. You could connect a bank of panels in series (daisy-chained) to produce a bigger voltage (not that you say you need to). Surely the issue is what current you want - power output equals volts x current in amps? An 80W, 12V solar panel produces 80/12 amps, or about 6.5A - enough to drive a portable TV. Yes, I guess you could use mirrors or lens to focus a larger areas of sun's rays into a smaller area onto a panel but I suspect the reality of the size of mirrors, setting them up, avoiding them getting covered in twigs, dust or birds' droppings probably makes it impractical and less effective than just buying another solar panel (or 2) to capture the same area of sun's rays as the mirror would have captured.

[qapmoc]

As a matter of interest, the solar cells which are normally available give less output as they get hotter, so focusing the sun onto them will not give the benefits which you might expect.

[lord molly]

it depends on what brand of PV cell you buy. many have a 12v out put, but most cells provide very little current. you may want to cheack out theis site, which has some good info on solar pannels

www.selectsolar.co.uk, which has info on both 12v and 24 pannesl of diffrent sizes

hope that helped you

lord molly

[Space]

Regarding the use of mirrors, I don't see how installing, cleaning and maintaining mirrors would be more impractical than installing, cleaning and maintaining the same surface of solar panels.

http://www.sciencemuseum.org.uk/exhibitions/energy/site/EIZCaseStudy4Item2.asp
mirrors are used for solar heating, I don't know whether they can be used for PV panels too...