String inverters vs microinverters vs optimizers

Decisions built from Microinverters / optimizers and Central string inverter — editorial analysis, no sales stake; each figure sourced or labeled in review.

All three boxes on your roof do the same job — turn DC power into usable AC. They differ in where the conversion happens, which panels can survive shade, and what breaks if one unit fails.

At a glance: Microinverters / optimizers vs Central string inverter

Microinverters / optimizersCentral string inverter
Shade tolerancePer-panel independenceOne shaded panel affects the series
If one unit failsOnly that panel is offThe whole string is off
Typical warranty25 years (in review)10-12 years (in review)
Upfront priceTypically adds to the quote (in review)Typically the cheaper box
Microinverters / optimizers · 2 reasonsCentral string inverter · 2 reasons

Each side's reasons below are one per line — the bar just scales those lists, no weighting.

When Microinverters / optimizers wins

When Central string inverter wins

The honest verdict

Your roof's shade pattern, not the brand, decides. Simple open roof → string or optimizer. Complex or shaded → micros earn their premium. Whatever you pick, get the inverter warranty from the installer in writing, and ask the $/W for all three options before comparing.

Where these figures come from

Federal credit rules from the IRS (accessed 2026-08-08); market prices from EnergySage 2026; export rates per state records cited on each state page (CPUC NEM 3 for California); typical-home usage EIA 2023. Anything verified carries its date; the rest says "in review" until confirmed.

Questions homeowners ask

How long does an inverter last?
Most string units have 10-12-year warranties (extension optional); microinverter brands now offer 25 a year. Warranties are the honest proxy because electronics age faster than panels (NREL-type data, in review).