These most common PV systems are also known as on-grid, grid-tied, utility-interactive, grid-intertied, or grid-direct. They generate solar electricity and route it to the loads and to the electric utility grid, offsetting a home’s or business’s electricity usage. Living with a grid-connected solar-electric system is no different than living with utility electricity, except that some or all of the electricity you use comes from the sun. The drawback of these batteryless systems is that they provide no outage protection—when the utility grid fails, these systems cannot operate.
In many states, the utility credits a grid-tied customer’s account for solar electricity produced during each billing cycle, which is then applied to periods when the system produces less or electrical consumption is greater. This arrangement is called net-metering or net billing. The specific terms of net-metering laws and regulations vary from state to state and utility to utility. In some states, a production incentive may pay the system owner a premium for PV system production. (See www.dsireusa.org for states’ incentives details.)