Solar Photovoltaic (PV)
Photovoltaic solar cells convert sunlight energy directly into electrical energy. Photovoltaic solar cells use the energy of the sun’s light to cause electrons to jump from semiconductor materials, such as silicon. Once moved, the electron wants to return, but cannot jump back. It gets back by flowing through wires and circuits which creates electron flow or direct current (DC) electricity.
Solar cells produce the most power when they directly face the sun. Some systems move the solar panels to track the sun as it moves across the sky. Other systems are fixed in a position to get the most direct sun over the entire year. In North Carolina, we would face the photovoltaics south at an incline of 25-40 degrees, similar to our latitude.
Photovoltaic solar cells will only produce electricity when the sun is shining, but we need electricity all the time, including at night. In a stand-alone system, batteries are used to store the energy. In a grid-connected system the PV system has an inverter to change the electricity to alternative current (AC) and connect with the utility grid. If the photovoltaics are producing more electricity than the house is using, typically during the day, power goes out to the utility grid for others to use. When the photovoltaics are not producing enough power, the house uses electricity from the utility grid.
The N.C. Clean Energy Technology Center provides solar PV assessments to citizens, businesses, and government entities in North Carolina. We also work with the Solar America Board for Codes and Standards to shed light on technical and policy matters relevant to solar industries.
Click here, to learn more about the State of Solar Photovoltaics in North Carolina.