Solar Photovoltaics

Photovoltaics, (PVs), are arrays of solar cells used to collect solar radiation and convert it into electricity. There are two types of modules that can be used in a PV solar array: crystalline silicon or thin film modules. Crystalline Silicon has been used for many years throughout the country and comes in a variety of panel sizes. Thin Film Modules, a newer technology, are more shade tolerant and are adhered directly to a different substrate such as metal roof panels.

As can be seen in the picture to the right, a typical installation has solar panels mounted on the roof. When energy from the sun hits solar cells, it produces direct current (DC) electricity. DC must be converted into Alternating Current (AC) to operate appliances in your home. This conversion takes place at the inverter, which synchronizes the electrical current from the solar array with that of the utility grid. Over 90% of PV systems installed today are solar arrays tied directly to the utility grid and allows the home to use either solar energy or traditional electricity. If the solar array produces more electricity during the day than the home uses, it will feed the extra electricity back to the grid. This electricity is sold to the utility company at the same rate that it is purchased, called “Net Metering.” Your current utility meter will be replaced with a new meter that is able to spin both forwards (when you are purchasing the power) or backwards (when you are selling the power back to the utility company). If power entering your home is disrupted, such as in a thunderstorm, it will also disrupt the synchronization of the inverter and your system will shut down until power is restored.

There are other variations of Solar Photovoltaic installations. For example, if you do not have a good solar location on your roof, you can mount the solar array on a pole. You can also add storage devices to the solar array in the form of batteries. This will allow you to run critical loads in the event that the utility’s power has been interrupted. Another variation could include installing a solar array that has no ties to the utility company. This system requires the use of batteries at a much higher cost of installation.

A solar array should be mounted on a roof system that is in good condition. A properly installed solar array can provide 20 years or more of energy-producing service.

The experts at Garlock-French Corporation can assist you in determining what photovoltaic system is right for you!