Solar Photovoltaic (PV)
Photovoltaic (PV) solar cells convert sunlight energy directly into electrical energy for immediate use. These cells use light radiation from the sun to cause electrons to collect on one side of the PV cell, creating a voltage. Once moved, the electrons want to return, but cannot easily cross back through the cell due to its internal electric field. Therefore, it gets back by flowing through wires and circuits connected to each side of the cell, creating a useable electron flow or direct current (DC) electricity.
Solar cells produce the most power when they directly face the sun. While some systems move the solar panels to track the sun as it moves across the sky, most simply remain fixed in a position that collects sun throughout the year. In North Carolina, panels should face the south at an incline of 25 to 40 degrees in order to get the most direct sun throughout the year. However, great electricity output occurs across a wide range of orientation and tilt.
Today, nearly all PV systems are connected to the grid and are often referred to as grid-tied. The energy produced by these systems is used immediately by on-site or nearby electric loads. . In a grid-connected system, the PV system has an inverter to change the electricity to alternative current (AC) power and connect with the utility grid. Many smaller systems are net metered, which means that more electricity is produced than the house site is using, Typically, power goes out to the utility grid for others to use, but when PV systems are not producing enough power, the house uses electricity from the utility grid.
The Center provides solar PV assessments to businesses and other entities in North Carolina. We also work to shed light on and find solutions to technical and policy matters relevant to the solar industry and that can be of use to the citizens of North Carolina.
Plug and Play PV: A N.C. Clean Energy Technology Center and FREEDM Center Project