PV Gap

Mitchell Said:

Why should I burn the copper sheeting for producing energy on a solar panel?

We Answered:

its not really the copper, its the oxide that forms on the copper that has the photoelectric properties. Its the oxide that absorbs photons and converts them into electricity.

Marion Said:

Solar Energy Panel VS. Energy Efficient Bulbs?

We Answered:

You should still get some output but you do expect less under an energy efficient bulb even though it looks brighter. This is because old bulbs give out a lot of 'light' in the infrared that you can't see. Which is completely wasted if you want it as a light bulb, but a solar panel may still harvest some of this energy!




Your solar panel is probably made of silicon. This has a 'band gap' of about 1.1 eV so any light with a wavelength shorter than about 1.1-1.2 microns be able to generate electricity. (shorter wavelength means higher energy)

Energy efficient bulbs give off the vast majority of their energy in the visible light range, which is about 0.45-0.8 microns. The spectrum looks something like this:
http://holeman.org/spectra/fluorescent%2…

It's hardly giving out any energy in the range from about 800-1100 nm, which is where the solar panel is most efficient at converting light into electricity (each photon can make 1 electron, which will give a specific amount of output power - any excess photon energy is wasted heating up the panel). The panel should still catch those photons and turn them into electricity, but it'll make far less current.


By contrast a non energy efficient light spectrum looks like this:
http://www.sciencebuddies.org/mentoring/…

It's giving off a good chunk of its energy as light in the range 800-1100nm which the solar panel can efficiently harvest into electricity. As a lightbulb though, this energy is being wasted because you can't see light of those wavelengths!