SolarEdge (DC optimizers + string inverter) and Enphase (microinverters) are the two dominant solar electronics platforms in California. For a small ADU system, the choice meaningfully affects upfront cost, monitoring, expandability, and battery options.
SolarEdge places a small DC optimizer behind each panel, then sends DC power to a single string inverter (typically wall-mounted next to the ADU's main service panel). Enphase places a tiny AC microinverter behind each panel — every panel produces grid-ready AC power independently.
On small ADU systems (2–4 kW), Enphase typically runs $300–$700 more than SolarEdge in equipment cost. The premium is usually worth it for shaded ADU roofs (where one shaded panel doesn't drag others down) and for landlords planning future expansion.
Enphase microinverters carry a 25-year warranty matching panel life. SolarEdge inverters carry 12-year (extendable to 25). Microinverters distribute failure risk — one failure affects one panel; a string inverter failure affects the whole system.
Enphase pairs natively with Enphase IQ Battery 5P. SolarEdge pairs with the SolarEdge Energy Hub + BYD/LG batteries, or commonly with a Tesla Powerwall 3 (which is AC-coupled and works with either platform).
For a small, unshaded ADU roof on a tight budget: SolarEdge. For a shaded or complex roof, planned expansion, or maximum reliability: Enphase. Either platform will pass Title 24 and California permitting.
On small (2–4 kW) ADU systems, Enphase typically runs $300–$700 more. On larger residential systems the gap narrows or disappears.
Either platform handles partial shade better than a basic string inverter, but Enphase's per-panel independence is the gold standard for heavily shaded ADU roofs.
Yes — adding panels is plug-and-play. SolarEdge expansions may require resizing the string inverter.