For providers to claim the commercial credit on your system, a required percentage of the equipment must be made from domestic materials. This is why programs specify hardware — Propel requires Enphase gear partly because it satisfies domestic content rules.
The homeowner consequence: qualifying American-made materials are in limited supply against surging demand. That's the quiet clock ticking behind 2026-2027 pricing — when the qualifying materials run out, the discounts tied to them end. It's also, honestly, good for the country: this rule has pulled panel and component manufacturing back onshore at record pace.