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Wednesday, 11 November 2009 15:42

The Basics of Solar Electricity

Here's a lesson for you on the basics of solar electricity --

The direct conversion of sunlight into electricity is known as photovoltaics or PV for short...

Photovoltaics (PV) is a technology that uses semiconductors to convert solar radiation into direct current electricity.

If you live in south Florida, the next time you drive across Alligator Alley take note of the many small modules powering the lights along the road, or the next time you stop at a road construction site notice the modules powering the signage.

After many decades of improvement and a decrease in the cost, solar technology is becoming more common in the United States.
For the home, there are two categories of PV:

    1. Grid-tied - where the home is connected to the utility grid and supple- ments energy needs by generating its own electricity with photovoltaics; and
    2. Off-grid, where the home is located too far from the utility cable so it generates all of its own energy with PV systems and often other sources.

Residential and commercial grid-tied PV systems, or supplemental power systems, have become the largest growth sector for PV.

There are four major components that make up a batteryless, grid-tied PV system:

    1. PV modules
    2. The inverter
    3. A mounting system and
    4. The balance of system (or BOS).

The PV modules generate DC electricity from sunlight.

They are grouped and wired together into what is called a PV array. The DC electricity is converted to AC electricity by the inverter and fed to the utility.

Mounting systems are the structures that hold the PV modules and they vary depending upon the type of roof. Finally, the balance of the system includes the module wiring, combiners, junction boxes, and disconnects.