Heat Pump Calculator
Heat pump vs natural gas: life cycle calculation with many options
Heat pumps can supply any house - but at which cost? A life cycle assessment.
Building
| Living space: | m² | ||
| Level of insulation | by standard of year | ||
| Temp indoor | °C | ||
| Heat per m2 | kWhtherm/m2 | ||
| Heat energy | kWhtherm/yrr | ||
| Heat pump efficiency for heating | COP (kWhtherm/kWhel) | ||
| lifespan | years |
Hot water
| Inhabitants: | |||
| Heat energy for hot water | kWhtherm/yr |
Carbon price prediction
Average price for natural gas (-) incl. carbon price: c/kWhtherm
Natural Gas
| Heat energy total (water + heating) | kWhtherm/yr | ||
| Natural gas efficiency | % | ||
| Gas tariff without carbon price | c/kWhtherm | ||
| Av. carbon price | $ | ||
| Consumption life cycle cost | $ | ||
| Base charge | $/yr | ||
| Maintenance | $/yr | ||
| Running costs life cycle | $ | ||
| Hardware purchase and installation | $ |
Heat Pump
| Electric energy for heating | kWh | ||
| heat pump efficiency for hot water | COP (kWhtherm/kWhel) | ||
| Electric energy for hot water | kWh | ||
| Electric energy total | kWh/yr | ||
| Electricity tariff | c/kWh | ||
| Electricity costs life cycle | $ | ||
| Maintenance | $/yr | ||
| Basic charge additional electric meter | $/yr | ||
| Running costs life cycle | $ | ||
| Hardware purchase and installation | $ | ||
| Funding rate | % | ||
| Own investment (excl funding) |
Heat pumps will always get your home warm. But at which cost?
The efficiency (COP) of a heat pumps depends on the level of renovation of a house. If thermal insulation is in a good condition, you can divide the electricity tariff by 4. If you pay 16c/kWh electricity, you will get one kWh of heat for 4c/kWh. In some countries there are even discounted electricity tariffs for heat pumps if you invest in a separate electric meter. With a growing share of renewable energy, electricity tariffs tend to decrease, while natural gas is becoming more expensive due to carbon pricing. Predictions are difficult and also depend on national politics. The default scenario here reflects the current situation in Germany.
A few remarks:
- Photovoltaics on your own roof can lower your effective electricity costs significantly. For the heat pump, this is most relevant in spring and autumn when it is already cold and the sun still has some elevation. But PV output in the winter is poor in higher latitudes.
- If offered, flexible electricity tariffs can minimize the heat pump's carbon impact and costs. In counties with a high amount of wind and solar power in the grid and decent carbon pricing, electricity prices drop to almost zero in hours with a high renewable share, whereas they rise when coal and gas plants feed the net. In this case, heat pumps should be synchronized with renewable production, using a 200 or 300 litre hot water storage. But it can also be the other way round: Without smart control, heat pumps tend to use most energy in the evening hours when temperatures go down, solar power is off and electricity demand is high.
- Every central heating system requires some electric energy for circulation pumps, typically around 150 kWh/yr- regardless of whether it is a heat pump, gas, oil or anything else
- Life spans are difficult to predict. Some gas boilers make 30 years, but not always. For heat pumps, estimations range between 15 and 20 years. But improvements have been rapid. Empirical values are lacking.
- Some gas boiler vendors advertise with a hydrogen-ready label. But it remains very speculative when and where (green) hydrogen or green methane will be competitive.
- The carbon price prediction reflects the path drafted for the European Union. In some EU-countries there is a national carbon price already now. With the ETS2 scheme, a common price in the buildings sector will be applied in in 2027 or 2028. Carbon certificates are to be reduced by 5% per year while at the same time gas consumption might decrease. Given this background, predictions are difficult. The final goal is carbon neutrality in 2050. In the USA, carbon prices - if introduced at all - vary from state to state. Other countries only have very low prices of about 10$/tCO2.
- Well-insulated houses require only little energy for heating. In this case, rising prices for natural gas do not carry too much weight, while investments for a heat pump in a central heating system are much higher than for a gas boiler. On the other hand you can expect a higher heat pump efficiency in newer houses.
- For small buildings or single rooms, domestic air-to-air heat pumps (air conditioners) could be worth a consideration. These devices are widely installed for cooling but they can also generate heat. Heating Efficiency of the latest products has improved drastically, making these devices competitive. Costs for purchase and installation are as low as 2000 - 3000$ (without hot water).
- Cheapest installation costs can be achieved with air conditioners in combination wth electric boilers. In this case, set the hot water COP to 1. However, this is only recommended if hot water consumption is low.
Apply default settings for air conditioner and electric boilers
- Calculation depends on the tariffs in your country
- Inflation costs are not part of this calculation
Conclusions
- Even in poorly insulated homes with a worst-case COP of 2, heat pumps are competitive due to rising tariffs for natural gas
- In well-but-not-perfectly insulated buildings, heat pumps score most. They still require a considerable amount of thermal energy, but heat pumps can reach high efficiency here.
- It always makes sense to invest in thermal insulation. 100.000 $ will easily be paid back in 20 years. Check out using the sliders.
- Carbon prices below 300$ do not set the required incentives for a rapid decarbonisation yet
Scheme:
