Photovoltaics

Photovoltaics (PV) are quite different। These parts collect light from the sun and transform them into electricity. These collectors are 5" wide diodes, usually Si, that generate charge carriers when exposed to light. ( I'll probably get into the physics of this device in a later blog.) A cell has about 0.6V and 5A (about 3W). The cells are stringed together in series to produce a module (laymen call these panels). Typically off-grid applications would require 30-50W modules. An on-grid installation uses 200W modules. (If you don't know what this means, just go outside your house and see if you have an electric meter. If you have one , then you're on-grid. ) If you have a house that consumes 1.5kW(1500W) of electricity at peak ( The sum of all wattage ratings of your appliances and lights), you will need about 10 200W panels to meet your electrical needs and system loses.

In a photovoltaic system you will also need to have a charge controller or control center and storage. The control center toggles between your modules and the grid (normal power from the utility). It also monitors the charge of your batteries. The storage batteries should be deep cycle ones like those used in an RV and not your car batteries. (Deep cycle batts provide 80% of their rated capacity vs. 20% for car batts.)

With all these components together you should be able to produce your own electricity. I'll be talking more about how to modules in a later blog...

An Ohio home with PV shingles
(taken from Picasa- Solar Gallery)