Energy From The Sun

Get Your Power From the Sun

Are you thinking about buying a solar electric system for your home or business? If so, this article provides some basic information that can help you.
Solar electric systems, which are also called photovoltaic or PV systems, are reliable and pollution-free. They make use of a renewable source of energy- the sun. And PV systems for homes and businesses are becoming more affordable all the time. PV works best in an energy-efficient building. So, adding insulation and energy-efficient lighting, appliances, and windows is a good idea, to reduce your home’s overall electricity use before you install a PV system.

To make PV systems even more affordable, most states offer financial incentives through solar rebates and other programs. Some utilities have net metering programs, which further enhance the economics of PV. Net metering means that when your PV system generates more power than you need, the excess goes to the utility grid and the meter runs backward. This allows you to receive full retail value for the power that your PV system generates.

This article, and the information on our website, can guide you through the process of buying a solar electric system. It is not a technical guide to designing or installing a system, for that information, we recommend consulting an experienced PV system designer or supplier.

BACKGROUND:
What is a solar electric or photovoltaic system?

Photovoltaic (PV) systems convert sunlight directly to electricity. They work any time the sun is shining, but more electricity is produced when the sunlight is more intense and strikes the PV modules directly (as when rays of sunlight are perpendicular to the PV modules, usually a southern facing area). Unlike solar thermal systems for heating water, PV does not use the sun's heat to make electricity. Instead, electrons freed by the interaction of sunlight with semiconductor materials in PV cells are captured in an electric current.

PV allows you to produce electricity without noise or air pollution, from a clean, renewable resource. A PV system never runs out of fuel, and it won't increase U.S. oil imports. Many PV system components are manufactured right here in the United States. These characteristics could make PV technology the U.S. energy source of choice for the 21st century.
The basic building block of PV technology is the solar cell. Multiple PV cells are connected to form a PV "module," the smallest PV component sold commercially. Modules range in power output from about 10 watts to 300 watts. A PV system connected or "tied" to the utility grid has these components:
One or more PV modules, which are connected to an inverter

The inverter, which converts the system's direct-current (DC) electricity to alternating current (AC)

Batteries (optional) to provide energy storage or backup power in case of a power interruption or outage on the grid.

AC electricity is compatible with the utility grid. It powers our lights, appliances, computers, and televisions.

Before you decide to buy a PV system, there are some things to consider:

First, PV produces power intermittently because it works only when the sun is shining. This is not a problem for PV systems connected to the utility grid, because any additional electricity required is automatically delivered to you by your utility. In the case of non-grid, or stand-alone, PV systems, batteries can be purchased to store energy for later use.

Second, unlike the electricity you purchase monthly from a utility, PV power requires an initial investment. This means that buying a PV system is like paying years of electric bills up front. Your monthly electric bills will go down, but the initial expense of PV can be significant, depending on the size of the system.
By financing your PV system, you can spread the cost over many years, and rebates can also lighten your financial load.

Finally, how old is your existing roof? If your existing roof is 10 years old or older, you'll want to carefully inspect your roof to determine how much life is left in it before taking the time and effort into installing your pv system. If your roof only has a few more years use left, you may want to replace your roof before installing your pv system.
If on the other hand you've choosen to go with solar shingles, you may be able to install the solar shingles over your existing shingles.