Microinverter vs String Inverter Calculator

Enter your system size, shading severity, and price premium for microinverters to see the production gain and payback period.

⏱ ~15 sec⚡ Shading-sensitive comparison🔒 No signup

Result

468 kWh/yr extra
Extra production with microinverters
Annual value$79.56
Payback period20.1 yrs

With no shading at all, microinverters offer little to no production advantage — their main benefit there is panel-level monitoring and easier fault diagnosis, not extra kWh.

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Why shading is the deciding factor

Production gain: none ≈ 0-2%, partial ≈ 5-8%, significant ≈ 10-25% of annual production

A string inverter's output is limited by its weakest connected panel — if one panel is shaded, it drags down the whole string's production, similar to a strand of old-style holiday lights. Microinverters optimize each panel independently, so the benefit scales directly with how much shading your roof actually experiences; on a fully unshaded roof, the extra cost mostly buys monitoring convenience rather than meaningfully more energy.

Frequently asked questions

Is there ever a shading level where string inverters are clearly better?

On roofs with no shading at all, a quality string inverter with power optimizers often captures nearly all the same benefit at a lower cost than full microinverters, since there's little mismatch loss to recover.

Do microinverters have other benefits beyond production?

Yes — panel-level monitoring makes it far easier to spot an underperforming or failed panel, and a single microinverter failure only affects one panel rather than an entire string.

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