Inverters are the brain of a grid-tied solar energy system. First, inverters convert the direct current generated by the solar panels into alternating current for a home’s lighting and appliances. In addition, inverters are the traffic cop of grid-tied systems. When solar panels produce more power than a household needs, the inverter sends the excess power back to the grid and spins the electricity meter backward -- a figure of speech since modern meters are digital -- to give the homeowner a credit. When the household needs more power than the solar panels can generate, such as at night, the inverter allows electricity from the grid to flow into the home.