Basics Applications Grid-Connected
What is a Grid-Connected Solar System?
Grid-connected systems use an inverter to convert the direct current (DC) electricity produced by the solar array to the alternating current (AC) used by the utility grid. When the sun is shining and making electricity, energy is flowing into the grid, running the meter backwards. When it is dark or cloudy and the house or business is using more electricity than the solar system is producing, the meter runs in the normal direction. The net effect is elimination or reduction of the electricity bill. The utility acts like a battery. The excess energy is used by other houses and businesses in the area. This is called net metering and is allowed by most utility companies, but not all. Check with your local utility before installing this type of system.
More information about grid-connected systems is in the book Solar Basics. Design examples for grid-connected systems are in the Solar Design book.