PV Gap

Mattie Said:

what is the factor of solar cell efficiency?

We Answered:

The angle does make a big difference. If the panel is on edge, or tilted 90 degrees to the direction of the incoming sunlight, then no light hits the face at all. If the panel is at a 60 degrees, half the light that it could have hit the face just goes past it. Only if it is oriented perpendicular to the incoming light does it intercept the maximum amount of light.

Russell Said:

Need a chart for efficiency drop-off for solar panels when mirrors are used with them.?

We Answered:

As was said above, this depends on the cell manufacturer. Generally, the cell efficiency will increase with the insolation level (W/m^2) but decrease with the temperature of the cell. The trick to concentrated PV is really finding a way to passively cool the cell while pumping in lots of light.
Most CPV companies use special high-efficiency cells for this. Try Amonix, or the nice DOE folks at Sandia.

Sandra Said:

How much power does the solar panel produce?

We Answered:

Area is 4' * 2' * (0.3048m/ft)^2 = 0.743m^2.

Incoming solar (assuming optimally oriented panel) averages about 1kW/m^2, so 743W max gross. 41% efficiency yields 300W.

Most panels are about 10% - 15% efficient, which is about 111W.

In either case, figure about 1/2 the theoretical efficiency for about 12 hrs per day.

so, you can run something from 50 to 150W about 12hrs per day. Too small for any appliance except maybe a laptop or light bulb.

Panels typically make about 12V, not enough to run household stuff anyway. Normally panels are used to charge batteries, then an inverter takes power from the battery to run your appliances.

Good luck!