What is this solar electric stuff, anyway? Photovoltaics (PV), is the conversion technology of light energy directly into electrical energy. When small particles of light, called photons, are allowed to strike a specially processed silicon wafer (i.e. cell), the photon energy dislodges electrons from their respective position in the silicon. When the silicon wafer (i.e. cell) is connected across a load (i.e. any device needing electricity to operate), the electrons will move through the circuit, providing power to the load. Power can also be stored in a battery. A typical PV panel is composed of many solar cells in order to provide a standard voltage and current output. A solar array can be comprised of any number of solar modules to provide power output for the purpose at hand.   conversion illustration

The sun is a virtually limitless source of “raw material” for power generation. Sunlight striking the equator in a 500 sq. mi. radius could generate enough electricity to equal the output of all electric power plants worldwide, if a highly efficient solar technology to harness it were to come along. Even with today’s PV conversion of sun-to-power efficiencies running between 10-15%, a typical home, with all modern appliances, could be amply powered with 50% of roof coverage in PV panels. Unfortunately, the cost of such a system would be ridiculously high. Although concern for the environment and energy independence are good reasons for choosing PV power, most often economics will drive the decision of whether or not to “go solar”. 

A solar-powered home must be energy efficient in order to keep solar electricity affordable today. The less power required, the less the system will cost. In the pages to follow, this will be discussed in greater detail.