Inverter Size Calculator

Inverter Types Explained

String Inverters

The most common and cost-effective option. All panels in a string are connected in series to a single inverter. Output is limited by the weakest panel — shading one panel reduces the entire string's output. Best for unshaded roofs with consistent panel orientation.

Microinverters

One small inverter per panel, mounted on the roof. Each panel operates independently, so shading one panel doesn't affect others. Higher upfront cost but maximizes production on complex roofs. Also makes panel-level monitoring easy.

Power Optimizers + String Inverter

A hybrid approach: DC optimizers are mounted on each panel and condition the output, then all power runs to a single string inverter. Better shade tolerance than a pure string inverter, lower cost than full microinverters.

DC:AC Clipping Ratio

Oversizing your array relative to the inverter (ratio >1.0) is standard practice. Panels rarely produce their rated peak wattage simultaneously. A 1.2 ratio means a 10 kW array paired with an 8.3 kW inverter — the inverter "clips" excess production on the best days but captures more energy on average days. Ratios of 1.1–1.3 are typical.

String Voltage Safety

String voltage is the sum of each panel's open-circuit voltage (Voc). It must stay below the inverter's maximum input voltage (600V or 1000V) at all temperatures, and above the MPPT minimum at normal operating temperatures. Violating max voltage can damage the inverter or create a safety hazard.