What is modeled — and what is not
Production
1,386 kWh/kW-year state planning benchmark from the existing PVWatts-based CalcuRiver dataset.
Installed cost
$2.59/W planning benchmark for Maryland.
Electricity value ceiling
21.41¢/kWh · EIA residential benchmark for Maryland (2026-07).
Pepco Maryland rate context
19.33¢/kWh · Summer off-peak modeled marginal base. This is utility rate-plan context, not a verified solar export-compensation rate.
Utility source: Pepco Maryland Schedule R-PIV tariff · verified 2026-09-28.
Production: NREL PVWatts methodology · Cost: 2026 state / local marketplace benchmark.
Solar export source: Pepco Maryland 2026 tariff book — Rider NEM · verified 2026-10-03.
Potomac Electric Power Company (Pepco) — Maryland export policy encoded
Pepco Maryland Rider NEM carries negative kWh forward until later consumption offsets the excess or until the annual true-up cycle before the end of April, unless the customer elects indefinite accrual. Residual annual excess is paid at the applicable generation/commodity portion rather than full retail value. The base planning result counts annual kWh that can offset household consumption and excludes any residual annual cash-out. Customers on time-metered schedules need a period-specific model.
Continue this Maryland cost analysis
Why this solar estimate changes
Solar value is driven by local production, installed cost, the retail value of electricity you avoid buying, and the compensation you receive for exported energy. CalcuRiver does not assume export credits equal the retail rate unless that utility program is explicitly verified.
Core logic: self-used solar offsets retail purchases; exported solar is valued only under a verified export-compensation rule.
Methodology & source policyConnect solar to the rest of the utility bill
Solar economics are easier to interpret when the tariff, storage and vehicle loads are connected to the same local context.