Behold The Power Of Panels
The panels contain silicon photoelectric cells that are connected in a series, sealed inside a glass-fronted panel, and can even generate some power on a cloudy day.
A panel can be designed to charge 12-volt batteries, and connecting two or more panels in series can charge batteries of a higher voltage. A panel converts from 7 percent to 17 percent of light energy to electric energy.
Panels are generally permanently mounted at the angle that yields the greatest average energy over the course of a day. Panels can also be mounted in adjustable frames, making it possible to change the angle to accommodate a change in seasons. The cells were originally designed for use in space, where repair costs are very high.
According to the U.S. Department of Energy, PV panels offer high reliability and low operating and construction costs. The panels provide energy without polluting the environment and can be built to any size.
As a pricing example, windstreampower.com offers PV panels in 20 watt, 50 watt, 75 watt, 90 watt, 100 watt, and 130 watt versions. These cost $297, $389, $525, $658, $695, and $1,069 per panel, respectively, and have a 25-year warranty.
Siemens and Solarex produce those panels.