How solar PV (photovoltaic) panels work

A solar panel is basically a sheet of glass covering a sheet of solar cells, which are made of a semiconductor material (typically silicon compounds). Sunlight passes through the glass and hits the silicon. Some of the sun's energy will knock loose electrons in the silicon, allowing them to flow through the material - creating an electric current. Each solar cell has conductors that capture the current and then the current from each cell is aggregated together for each panel.

There are no moving parts, nothing to break, and once the panel is installed it will generate power for 20+ years. The only requirement to generate power is sunlight, and the only maintenance required is cleaning dust or the occasional bird dropping off of the glass.

More detailed explanations can be found at:

- http://en.wikipedia.org/wiki/Photovoltaic_cells
- http://science.howstuffworks.com/solar-cell1.htm

Pay for the Power, Not the Panels
"The P.P.A. model is becoming the dominant model," said Edward Levin, vice president for global capital markets at Morgan Stanley. "It is no longer a plausible business model for a solar developer to sell panels to a property owner or corporation."

The market for commercial solar power installations is not based solely on environmental concerns. Solar power is exploding because of "pure economics," said Barry Neal, director of environmental finance at Wells Fargo.

Companies like Wal-Mart and Kohl's are turning to solar power because "they can actually reduce their electricity costs, particularly in states like California and New Jersey," where electricity rates are high and rising, Mr. Neal said. Those states, which also offer generous incentives, account for about 85 percent of solar installations in the country.

NYTImes - 3/26/08





Solar Panel