Inverter
/ in-VUR-ter /
Also known as: solar inverter, string inverter, microinverter
Definition
An inverter is the device in a solar PV or battery system that converts direct current (DC) from the panels or battery into the alternating current (AC) used by household appliances and the grid. It also manages the connection to the grid and shuts the system down if the grid supply fails.
In practice
A string inverter handles a whole group of panels and is usually the cheapest option. Microinverters or power optimisers work at panel level and help where parts of the roof are shaded or face different directions. A hybrid inverter can also manage a battery. Inverters often need replacing before the panels, commonly after around 10 to 15 years, so check the warranty.
The inverter output rating, not the panel capacity, usually determines whether a system falls under the G98 or G99 grid connection route. Its maximum AC output is the figure that counts.
Building Regulations
Specific requirements come from the engineering recommendations for grid-connected generation. Your installer should confirm the correct route for your system.
Full guide: Solar PV for UK homes