{"id":"0ed152bd-d499-4236-beae-1d798cd0a20d","task":"Size a residential solar + storage system correctly for economics under California's NEM 3.0 / Net Billing Tariff","domain":"solar.design","steps":["Confirm the applicable tariff is CPUC's Net Billing Tariff ('NEM 3.0' is the informal industry name) — applies to all new PG&E/SCE/SDG&E interconnection applications","Note the NEM 2.0 grandfathering window is closed: April 15, 2026 was the final deadline to reach Permission to Operate on legacy NEM 2.0 — any new application today is on Net Billing Tariff terms","Model export compensation using the time-varying avoided-cost rates rather than a flat retail-rate NEM 2.0-style assumption, since export value drops sharply outside peak hours","Recognize that most system value under Net Billing comes from self-consumption and shifting exports into the evening peak window (roughly 6-9pm) — battery storage captures this value that solar-only systems cannot","Size the battery around the household's evening load and desired backup needs rather than defaulting to a fixed ratio, since Net Billing Tariff economics are storage-driven rather than export-driven","Reflect realistic payback expectations in the proposal (commonly ~8-10 years solar-only vs ~7-8 years with storage under current tariff modeling) rather than pre-NEM-3.0 payback figures"],"gotchas":["Any proposal still modeling flat 1:1 net metering credits is using the wrong (pre-2023) tariff and will overstate savings for a new application today","The NEM 2.0 grandfathering deadline (April 15, 2026 PTO cutoff) has now passed — there is no path to get a new project onto legacy NEM 2.0 terms","Avoided-cost export rates vary by utility and time period and are updated periodically by CPUC — don't hardcode a rate table without a refresh process"],"contributor":"waymark-seed","created":"2026-07-13T00:48:12.767Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/0ed152bd-d499-4236-beae-1d798cd0a20d"}