Solar panels generate direct current (DC). Homes, businesses, and the grid run on alternating current (AC). The inverter is the device that converts one into the other — and it does more than just conversion.
What an inverter does
An inverter takes the DC from the array and switches it rapidly to create AC that matches the frequency and voltage of the local grid. This is the same principle behind many everyday power electronics, scaled up. Without the inverter, a solar array could not power household appliances or export energy to the grid.
The main arrangements
Inverters come in several arrangements, each a design choice rather than a universal winner:
- String inverters serve a group (or string) of modules from a single unit, usually mounted near the electrical panel.
- Microinverters are small units attached to individual modules, converting power at the panel itself.
- Hybrid inverters are designed to work with battery storage as well as the grid, managing both directions of power flow.
Which arrangement suits a site depends on shading patterns, roof layout, monitoring preferences, and whether batteries are part of the plan — questions a system designer works through.
Monitoring and safety
Modern inverters also monitor the array's output and enforce grid safety functions: if the grid goes down, a grid-tied inverter is designed to stop exporting so line workers are not endangered. In systems with batteries, the inverter's job extends to managing charge and discharge.