Free Tool

STC Calculator

Calculate Small-scale Technology Certificates for solar & battery installations

Postcode *

Used to determine your STC zone rating

System Size (kW) *

Or calculate from panels below

Panel Wattage (W)

Number of Panels

Battery Capacity (kWh) — optional

Installation Date *

⚠️ Battery STC rate change: The battery STC multiplier drops from 8.4 to 4.2 on 1 May 2026. Installations completed before this date receive the higher rate. Factor this into your timing.

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