PV Gap

Jerry Said:

the greenhouse effect gets its name from the florist's greenhouse where glass prevents reradiated solar?

We Answered:

b.ultraviolet light to enter and preventing longer waves is correct:
"Since the glass acts as a one-way valve, allowing short-wavelength solar radiation ( > ultraviolet light ) to enter and preventing long-wavelength radiation from leaving, flipping over the glass would not change the situation."
http://www.sci-ctr.edu.sg/ssc/detailed.j…

Jerry Said:

Can a magnifying glass , if bigger enough, focus solar light to melt aluminum or magnesium in outer space ?

We Answered:

Yes, it could. What you're describing is called a solar furnace. Only people generally use a parabolic mirror instead of a refracting lens, but the result is the same. And they don't just work in space, people have built them here on Earth already. Under the right conditions, a solar furnace can even melt steel.

Maureen Said:

The greenhouse affect gets its name from the florist's greenhouse, where glass prevents reradiated solar ?

We Answered:

b. Glass blocks the UV and IR radiation from entering. The temperature inside the greenhouse ensures that the vast majority of energy re-radiated is in the IR which the glass prevents from leaving the greenhouse.

Pearl Said:

why dont you put an magnifile glass on the top of solar penals to get more heat and light ?

We Answered:

You are talking about two different applications: photovoltaic (Si) and solar heating.

A magnifying glass concentrates the light into a small spot so the total amount of energy is still limited by the area. If the lens collects light from more angles (so it focusses more light onto the collector over a larger range of sun angles, like the fresnel lens), then you might get a net increase in solar energy collected.

For solar heating, a small very hot spot may not be an advantage, depends on the details of energy generation. For a solar furnace that boils water to make steam to generate electricity, this is a very good thing (although the actual systems use parabolic mirrors to do the focusing). If it is passive solar heating for residential, a single hot spot doesn't help and probably increases the heat losses.

Good question

Ruby Said:

Painting the inside of glass light fittings?

We Answered:

Another option would be to light it with a "daylight" lamp or a yellow light bulb and forget the paint/tint mess.

Bruce Said:

what is Glass, Solar-Ray light tinted, heat rejecting, is it different from sunroof?

We Answered:

what ??? make sense

Jack Said:

Can a magnifying glass , if bigger enough, focus solar light to melt aluminum or magnesium ?

We Answered:

Yes, it can; and so can a curved mirror. Sunlight reaches the surface of the Earth at an intensity of about 40 watts per square metre; if you concentrate enough of that energy in a small enough area you can generate in principle as much energy as you need for pretty much anything.