Heat pump power consumption

Are heat pumps electricity guzzlers?

This headline is admittedly somewhat provocative, but this article is intended to show the potential heat pumps offer when it comes to achieving the energy transition. But are there also cases from the other perspective where using a heat pump may not be efficient? Let's look at this topic in detail.

No matter what way you look at it...

The existence of climate change and its impact on our daily lives can no longer be denied. Due to global warming, it is more important now than ever that we decarbonize the energy sector by scaling back and ultimately ending the use of fossil fuels such as oil, coal, and natural gas.

Transitioning from fossil fuels and atomic power to a renewable energy supply is called the energy transition and comprises the power, heat, and mobility sectors. Expanding the production and use of these renewable energies can, together with increasing energy efficiency, be considered one of the key challenges of the 21st century.

With our state-of-the-art heat pump systems, we at TOSHIBA are playing an active role in successfully bringing about the energy transition.

How much electricity does a heat pump need?

It's clear that even heat pumps cannot work fully independently of the power grid, as a small amount of electricity is needed to operate the pump system. But how large are the potential savings in specific terms? To answer this question, we first need to discuss two important performance indicators.

A clear comparison – two performance indicators for cool heads

The two most important performance indicators for calculating heat pump efficiency are

the coefficient of performance and
the seasonal performance factor.

1. The coefficient of performance of a heat pump

The coefficient of performance indicates the ratio between the heat output emitted to the heating circuit and the electric power absorbed by the heat pump. Since the coefficient of performance only reflects a moment in time, it changes constantly and is only meaningful to a limited extent.

Example coefficient of performance
For example, a coefficient of performance of 4 means that 4 kWh of heating energy is produced with every kWh of electricity used.

2. The seasonal performance factor of a heat pump

The seasonal performance factor relates to any entire year's heat pump operation and is therefore significantly more revealing than the coefficient of performance. It is the most important performance indicator for heat pumps in terms of energy efficiency.

If a heating system has a seasonal performance factor of 4, it therefore also means that 1 kWh of electric power had to be used for 4 kWh of heating energy gained. However, this is a year-on-year comparison and does not just relate to a single point in time.

A heat pump's power consumption ultimately depends on the ratio of heating capacity to seasonal performance factor.

The relevant formula is:
Annual heating capacity in kWh/seasonal performance factor = annual electricity consumption in kilowatt hours

Example calculation

If you assume an annual heating capacity of 10,000 kWh (for heating and hot water) and a guideline value for the seasonal performance factor of 4, this results in the following calculation for the annual electricity consumption: 10,000 kWh / 4 = 2,500 kWh

Summary: The more efficient the heat pump, the higher the seasonal performance factor and the more economical it is to run the heat pump.

Greater efficiency through building measures

The efficiency of a heat pump can be further increased with various structural measures. Of course, these measures are easiest to implement with new build projects. However, there are opportunities to optimize the amount of energy needed in existing buildings. Some of these measures include:

Installation of underfloor heating
Thermal renovation of the building shell
Installation of energy-saving windows
Insulation of water pipes
Combination of heat pump and PV system

Efficient and economical – our summary:

A heat pump from TOSHIBA saves electricity and makes an active contribution to achieving the energy transition
A heat pump's power consumption is calculated based on the ratio of heating capacity to seasonal performance factor
The higher the seasonal performance factor, the higher the system efficiency
The heat pump efficiency can be boosted further using suitable measures.
The ESTIA air-to-water heat pump heats at a ratio of 4:1 of energy from the air and electrical energy on average.
The cost-effectiveness of a heat pump can be increased further by taking corresponding measures on the building.

Widespread use of heat pumps offers enormous potential in terms of the energy transition. State-of-the-art units from TOSHIBA are at the forefront when it comes to efficiency and economy. You can find further information at: Link to TOSHIBA heat pumps

Overview of TOSHIBA heat pumps