MCS-style annual output check (UK)

Multiplies kWp, a Kk value and a shade factor, as the MCS 032 formula does, and compares the result with your design tool.

A worked-maths aid, not an MCS estimate and not legal advice. The Kk value must come from the MCS tables for your postcode region, inclination and orientation: the presets use invented Kk values and invented tool estimates. Shade factor 1.00 is for a clear horizon with no near or far shading. Your certification body's rules come first.

Examples (all inputs invented):
Array size (kWp)-
MCS-style annual AC output-
Tool estimate against the MCS-style figure-
What it means-

Formula as MCS 032:2025 Issue 1.0 prints it (check the current issue in the MCS library): annual AC output (kWh) = kWp x Kk x SF, with kWp the sum of the module data plate values at STC. We round to the nearest kWh; the rounding rule in MCS 032 was not checked. Percentages are the tool figure minus the MCS-style figure, divided by the MCS-style figure.