Solar irradiance + PV-yield forecast for any coordinate (free/keyless, global). Returns a daily 1-16 day forecast: GHI (kWh/m²), peak sun hours, sunshine hours, and estimated yield per kWp of panels (at a 0.75 performance ratio). For rooftop-solar planning, agrivoltaics, and EV-charge scheduling. Complements energy.solar-resource (NREL long-run averages, US).