A solar inverter, or PV inverter, converts the variable direct current (DC) output of a photovoltaic (PV) solar panel or battery bank into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-grid electrical network. It is a critical component in a photovoltaic system, allowing the use of ordinary commercial appliances. Solar inverters can have special functions adapted for use with photovoltaic arrays, including maximum power point tracking and anti-islanding protection.
- Stand Alone Inverters, used in stand alone power systems where the solar inverter draws its DC energy from batteries charged by photovoltaic arrays. Many stand alone inverters also incorporate integral battery chargers to replenish the battery from an AC source, when available. Normally these do not interface in any way with the utility grid, and as such, are not required to have anti-islanding protection.
- Grid Connect Inverters, which match phase with a utility-supplied sine wave. Grid connect inverters are designed to shut down automatically upon loss of utility supply, for safety reasons. They do not provide backup power during utility outages.
- Hybrid Inverters, are special solar inverters which are designed to draw energy from a battery, manage the battery charge via an onboard charger, and export excess energy to the utility grid. These inverters are capable of supplying AC energy to selected loads during a utility outage, and are required to have anti-islanding protection.