Inverter
Device that converts the DC electricity produced by solar panels into AC electricity usable by home appliances and the utility grid.
Solar panels produce direct current (DC), but homes and the grid operate on alternating current (AC). The inverter performs this conversion — and its efficiency (typically 96–99%) directly affects system output. Three main types serve residential installations.
String inverters connect all panels in series into one central unit. They are cost-effective but are limited by the weakest panel — partial shading of one panel reduces the entire string's output. Microinverters attach to each individual panel, allowing each to operate independently. They maximize production in shaded or complex-roof situations and provide panel-level monitoring but cost more. Power optimizers are a hybrid: DC-side optimizers on each panel condition the output before sending it to a central string inverter, mitigating shading losses at lower cost than microinverters.
Inverter lifespan is typically 10–15 years for string inverters and 25+ years for microinverters — an important long-term cost consideration.
Real-World Example
The installer recommended microinverters because the roof had a dormer that shaded the upper-left panels for three hours each afternoon; without per-panel optimization, that shading would have reduced the entire array's output by 30%.