Estimate heat pump electricity from heat demand and seasonal performance · India

Keep heat demand and electricity separate

Useful heat delivered to rooms or hot water is measured in thermal kWh. Electricity supplied to the heat pump is another energy input. If annual useful heat demand is an illustrative 12,000 kWh and seasonal performance is 3, the simplified electricity requirement is 4,000 kWh. This does not mean every home needs that amount.

COP and SCOP answer different questions

COP describes heat output divided by electricity input at stated operating conditions. SCOP summarises standardised seasonal operation. Neither is a guarantee for a particular installation. For an annual estimate, use a suitable seasonal assumption or measured annual performance, and check the climate and temperature conditions behind a product's published rating.

Define what your estimate includes

Identify whether demand includes space heating, domestic hot water or both. Also establish whether the performance figure includes backup heating, circulation pumps and other auxiliaries. Avoid adding their consumption twice. Building heat loss, emitter temperatures, controls and weather affect operation, so compare several seasonal performance values instead of relying on one attractive rating.

Compare gas on useful heat delivered

For direct electric resistance heating, the simple comparison assumes one electrical kWh per useful thermal kWh at the heater. For gas, divide useful heat demand by the assumed seasonal boiler efficiency to estimate fuel energy. Use compatible energy units and billing definitions. Compare the resulting costs, adding fixed charges only when they actually change between options.

Check the financial and practical limits

Annual savings equal the previous system's comparable cost minus the heat pump cost. Divide additional investment by positive savings for simple payback; zero or negative savings have no finite payback in this model. Maintenance and financing are separate. Equipment sizing and radiator suitability require a qualified assessment of the building, not just an annual energy calculation.

Data sources

Last reviewed: 2026-09-08