Entered Solar Resource Generation Scenario Calculator

How the entered solar resource generation scenario calculator works

Monthly energy is entered array capacity × supplied daily equivalent peak-sun hours × calendar days × retained system share × supplied resource/orientation multiplier. The calendar accounts for leap years. Each month has its own resource input; the starting values are illustrative and are not a location or weather dataset.

Resource and adjustment must share a documented boundary. If peak-sun hours already describe the intended plane of array, use a 100% adjustment. Avoid applying orientation, inverter or other losses twice if they are already embedded in the supplied resource or retained-output assumptions. Annual output sums the twelve modeled months; specific yield divides it by positive entered capacity.

This intentionally bounded scenario is not a PVWatts implementation or a weather forecast. There is no location, shading, temperature, module, inverter clipping, tilt/azimuth or dispatch calculation. The source describes broader model inputs so the distinction is explicit; no generation, project performance or supplier rating is guaranteed.

Worked example

In non-leap year 2026, 5 kW with 4 equivalent peak-sun hours every day, 20% losses and a 100% resource adjustment gives 5 × 4 × 365 × 0.8 = 5,840 kWh. The twelve-month average is approximately 486.667 kWh. Raising entered capacity to 10 kW doubles the annual scenario to 11,680 kWh.

Sources and assumptions

The source material explains the underlying calculation or pricing structure. Entered prices, costs, schedules and scenario choices are your assumptions; this tool does not obtain supplier quotes or predict actual results.

• SAM: PVWatts model inputs and scope