A qualifying no-upfront solar-plus-battery PPA can give a PG&E homeowner access to equipment without buying it upfront. To understand the long-term offer, ask for more than the first year's production total: request the solar generation assumed in every contract year.
That forecast connects the roof's expected output to PPA payments, remaining utility purchases and energy available for battery charging. Clear assumptions make proposals easier to compare.
Ask how the forecast accounts for aging
Solar production estimates should distinguish gradual equipment aging from changes in weather, shade or equipment availability. A Department of Energy research summary, published June 27, 2023, explains how measured performance loss affects lifetime energy and financial estimates. Its study covered commercial, industrial and utility-scale systems; its fleet results are not a prediction for your roof.
Ask the provider which annual degradation assumption it uses, why that assumption fits the proposed equipment, and whether the first year is treated differently. Request the equipment model and the resulting year-by-year kilowatt-hours. If two proposals show different lifetime output from similar systems, that is a useful question to resolve before comparing their payment totals.
A manufacturer's panel warranty, the provider's production guarantee and the proposal's expected generation are separate documents. Our production-guarantee guide explains the distinction between an estimate and a contractual promise.
A lower generation estimate can also lower energy payments
The CPUC solar guide explains that a PPA provider owns the solar system and typically charges for the electricity it generates at the contract's per-kilowatt-hour rate. Confirm your agreement's actual billing method.
Consider a hypothetical model with these assumptions:
- Year-one billable generation is 10,000 kWh.
- Each later year's generation is 0.5% below the preceding year.
- The energy price remains fixed at $0.20 per kWh.
- Separate fees and utility charges are excluded.
Year ten follows nine annual reductions: 10,000 × 0.995⁹ = about 9,559 kWh. Its modeled energy payment is about $1,911.78, compared with $2,000 in year one, using the unrounded generation estimate.
These are illustrative inputs, not available offers, equipment specifications or a savings estimate. If the PPA rate escalates, that year's price must also change in the calculation. Lower PPA energy payments alone do not establish a lower combined household bill.
Recalculate the remaining PG&E costs
PG&E's Solar Billing Plan places residential participants on Electric Home and includes monthly statements, import charges, export credits and continuing charges. Existing NEM customers need a comparison using their own arrangement.
If future solar output is lower, the model should also reconsider household solar use, battery charging, grid purchases and exports. It should not reduce PPA payments while leaving every other energy flow unchanged without explanation. The effect depends on when the lost generation would have been used or exported.
Request annual results using consistent household demand, with any planned EV or appliance changes identified separately. Future utility prices are assumptions, not contractual guarantees.
Include the battery's later years
PG&E's battery guidance explains that backup depends on battery size, energy use, available solar and supported circuits. Ask whether the long-term model assumes battery aging or replacement, who pays for replacement, and whether its assumed reserve matches your outage priorities. Annual solar production does not establish runtime during a particular outage.
Confirm qualification, upfront amounts, rate and escalator, contract length, battery ownership and fees, maintenance and home-sale transfer terms. No upfront purchase does not mean free electricity or guaranteed savings.
Bring the annual production and payment schedules to West Coast Alternatives to discuss a PG&E-area solar-plus-battery PPA with assumptions you can follow from year one onward.