Not the Same as Daylight Hours
A location may have 12 hours of daylight but only 5 peak sun hours. Morning and evening irradiance is lower than midday irradiance, so the daily energy is condensed into an equivalent full-power period.
Basic Energy Estimate
Daily kWh = array kW × peak sun hours × system efficiency
A 6 kW array, 5 peak sun hours, and 80% overall efficiency produces an estimated 24 kWh/day.
Choosing Solar Data
Use site-specific irradiance data for the intended panel tilt and orientation. Annual averages help estimate grid-connected yearly production. Off-grid systems often require conservative winter or low-sun-period values.
Losses and Variability
Temperature, inverter efficiency, wiring, mismatch, soiling, shading, snow, degradation, clipping, and downtime reduce output. Weather also causes substantial daily and annual variation.
A basic peak-sun-hours estimate does not replace hourly production simulation or site shading analysis.