Microinverter or String Inverter? Compare a Solar Proposal

How the layouts differ

DOE says PV systems may use one inverter to convert electricity from all modules or microinverters attached to each module. DOE, “Solar Photovoltaic System Design Basics”

Shading, cost and service

DOE says a single inverter is generally less expensive and easier to cool and service; microinverters allow independent panel operation, which may be useful where modules are shaded.

DOE says string inverters serve a set of panels; shading on one panel can reduce that string’s production. DOE, “Solar Integration: Inverters and Grid Services Basics”

Compare the written proposals

DOE’s general descriptions do not establish this roof’s production, fit, price, or service terms.

Compare each exact model and architecture, module grouping and shading assumptions; keep the bidder’s production estimate, price, and service or warranty scope separate. Ask for missing details in writing.

If one bid omits its model or shade premise, request that detail before comparing estimates.