gridconnected

Grid-connected refers to electrical systems that are connected to the public electrical grid, allowing them to import electricity from the grid and export electricity into it. This configuration is common for residential and commercial installations that use distributed generation such as solar photovoltaic, wind, or small combined heat and power units. The grid serves as the voltage and frequency reference and as a backup source when local generation is insufficient.

In a typical grid-connected setup, a system such as a solar array generates direct current that is converted to alternating current by a grid-tied inverter. The output is synchronized with the grid and fed through a meter to either the local loads or back into the grid. Net metering arrangements or feed-in tariffs may credit the owner for energy exported to the grid. Many systems include protective equipment and metering, and some use smart inverters that can provide grid support, power factor control, and other ancillary services. Storage can be incorporated to increase self-consumption, though it commonly does not enable islanding without additional controls.

Safety and regulatory requirements govern grid-connected systems to ensure grid safety and reliability. Interconnection standards such as IEEE 1547, UL 1741, and EN 50438 require anti-islanding, meaning the system must shut down when the grid fails, unless part of a larger, explicitly designed microgrid with storage and control capable of safe islanding. Utilities may impose connection, protection, and metering requirements, and regional rules influence incentives and compensation for exported energy.

Variants include storage-enabled systems and microgrids that can operate independently for short periods during grid outages. Overall, grid-connected systems offer energy cost savings and emissions reductions while relying on the grid for reliability and safety.