SnapEnergyLab

Heating and heat pump tools

Heat pump vs electric heater

A resistance heater turns one kilowatt-hour of electricity into one kilowatt-hour of heat. A heat pump moves heat rather than creating it, so the same electricity delivers several times more.

Is a heat pump cheaper to run than an electric heater?

For the same delivered heat, yes — by a factor set by the heat pump’s seasonal performance. A 1,500 W resistance heater running 8 hours a day uses 12.0 kWh per day and 365 kWh over an average month, all of which becomes heat, costing $65.74. A heat pump with a seasonal performance factor of 3.0 delivers that identical 365 kWh of heat from 122 kWh of electricity, costing $21.91 — $43.83 less per month at $0.180/kWh. Equipment and installation costs are excluded.

Same heat, different electricity

Delivering 365 kWh of heat over an average month at $0.180/kWh.
SystemElectricity usedRunning costDifference vs resistance
Electric resistance heater365 kWh$65.74—
Heat pump, SCOP 2.0183 kWh$32.87$32.87
Heat pump, SCOP 2.5146 kWh$26.30$39.45
Heat pump, SCOP 3.0122 kWh$21.91$43.83
Heat pump, SCOP 3.5104 kWh$18.78$46.96

Why the physics allows this

At the point of use, electric resistance heaters convert essentially all of the electricity they consume into heat, and they cannot exceed one-for-one: every joule in becomes a joule of heat. Two heaters drawing the same 1,500 W therefore deliver approximately the same total heat while they are drawing that power, although controls, cycling and heat distribution can change comfort and total energy use over time.

A heat pump does something different. It uses electricity to run a compressor that moves heat from outdoor air into the house. Because most of the delivered heat is collected rather than generated, a unit of electricity can deliver two, three or four units of heat. That ratio is the coefficient of performance, and it falls as the outdoor temperature drops, because there is less ambient heat to collect and a bigger temperature lift to achieve.

Use a seasonal figure, not a rated peak

A rated COP is measured at a specific operating condition. It is a point measurement, not a whole-season result. For seasonal cost estimates, SCOP is more useful because it represents performance across a defined heating season, including the cold days when performance is worst. Your actual seasonal performance can still differ because of climate, flow temperature, controls, sizing and installation. Substituting a rated COP for a SCOP is the most common way heat pump savings get overstated.

Run the comparison on your own numbers

Your inputs

Annual electricity attributable to heating. If your bill does not separate heating from other loads, this will need to be estimated.

1.0 for electric resistance heating — baseboards, panel heaters, electric furnaces.

A season average, not a rated peak COP. Actual seasonal performance depends on climate, flow temperature, system design and controls.

Scenario: heat pump SCOP

$720.00

lower running cost per year

Same 6,000 kWh of heat delivered, 67% less electricity cost

Scenario estimate
Heat delivered
6,000 kWh
Electricity now
6,000 kWh
Electricity with heat pump
2,000 kWh
Running cost change
−$720.00
Annual running cost for the same delivered heat.
SystemPerformance factorElectricity usedRunning cost
Current system1.06,000 kWh$1,080
Heat pump3.02,000 kWh$360.00

Lower running cost under these assumptions

This is a running-cost comparison only. It excludes purchase and installation, so it is not a payback calculation. Enter your own SCOP to test how sensitive the result is.

Method

  1. Heat delivered: 6000 kWh of heat
  2. Current: 6000 ÷ 1 = 6000 kWh electricity → 1080 USD
  3. Heat pump: 6000 ÷ 3 = 2000 kWh electricity → 360 USD
  4. Difference: 720 USD

Assumptions

  • Seasonal performance factor of 3 for the heat pump — a season average, not a rated peak COP.
  • Current system performance factor of 1.
  • Both systems are assumed to deliver the same amount of heat into the home.
  • Electricity rate of 0.18 USD/kWh for both systems, with no standing-charge or tariff difference.
  • Installation cost, maintenance, distribution losses and comfort differences are not included.

What can change the result?

  • Seasonal performance factor, which varies with climate and system design
  • Flow temperature — high-temperature radiators reduce performance significantly
  • Your electricity tariff and whether heating has a separate rate
  • Backup resistance heat used during the coldest hours
  • Building insulation, which determines the heat demand both systems must meet

Your next decision

Heating and heat pump tools