daikin heat pump

Solar powered heat pump – how much power do I need?

Table of contents

In an era of constant increases in electricity and heating bills, more and more people are looking for cheaper alternative solutions. One of them is to combine a heat pump with a photovoltaic system. In this article we will try to introduce the subject of combining these two systems. In particular, we will focus on the problem of selecting the appropriate power of photovoltaic installation and heat pump for buildings with different square meters and heat demand. We will also discuss the benefits of such a solution and the cost and payback time of the investment. We invite you to read more!


1 What is a heat pump and how does it work?

A heat pump is an advanced heating device that uses energy from the environment, contained in air, soil or water, to provide heat to a building or use it for cooling. A heat pump works by delivering heat from a lower temperature to a higher temperature. It uses a refrigerant circuit. An evaporator draws heat from a lower temperature source. Then, with the help of a compressor, the temperature of the refrigerant rises and the accumulated heat is transferred to the target area with a higher temperature. This process repeats cyclically, enabling efficient heat transfer. Heat pumps are an efficient and environmentally friendly solution that saves electricity and reduces CO2 emissions compared to traditional heating systems based on fossil fuels. You can read more about the principle of operation and heat pumps here.

daikin heat pump
Fig. 1 Heat pumps from the renowned Daikin company.

2 Benefits of combining photovoltaics with a heat pump.

Combining a photovoltaic system with a heat pump can bring many benefits. In addition to supplying electricity to heat pumps, photovoltaics can also support other home systems. Here are the three main benefits of such a combination.

2.1 Lower electricity bills

Photovoltaic modules generate electricity from a free and unlimited source – the sun. The energy produced in this way can be used to power a heat pump, which will reduce the operating costs of the heating system. Thanks to this combination, energy consumption from the grid can be reduced, which translates into lower electricity bills.

2.2 Eco-friendliness and reduction of CO2 emissions

Combining photovoltaics with a heat pump is also a beneficial solution from an environmental point of view. Photovoltaics is a renewable energy source, which means that the production of electricity does not involve the emission of harmful substances or greenhouse gases. Combining it with a heat pump further enhances this effect, since a heat pump is an efficient heating system that uses renewable energy to heat (or cool) a building.

2.3 Energy self-sufficiency

Combining a heat pump with photovoltaics can lead to energy self-sufficiency. This means that the building is able to generate enough electricity through solar panels to power both the heat pump and other electrical appliances in the building. Energy self-sufficiency gives independence from traditional energy suppliers, and also protects against rising electricity prices.


3 Choosing the proper heat pump power

Choosing the right heat pump power is one of the key factors determining the effective and efficient operation of the heating system. Correct selection of heat pump power allows you to ensure optimal thermal conditions in the building, while minimizing operating costs and ensuring energy efficiency. In this section, we will discuss the factors to consider when selecting the right heat pump power.

3.1 Area for heating/cooling

The surface area of a building is one of the key factors determining the need for heat energy. The larger the area for heating/cooling, the more heat pump power will be needed. Various methods of calculating the area are also presented, such as the measured method or the calculation method based on building dimensions.

3.2 Insulation of the building

A well-insulated building has less heat loss and is more energy efficient. When selecting the power of a heat pump, it is important to consider the quality of insulation of the walls, roof, floor, and windows and doors.

3.3 Energy efficiency

The efficiency of a heat pump is determined by the seasonal performance coefficient (COP) or energy efficiency ratio (EER) for cooling. The higher the COP or EER value, the more efficient the heat pump is. Different energy efficiency classes of heat pumps and their impact on energy consumption and operating costs are also shown.


4. How much power of photovoltaic installation for a heat pump?

When selecting the power of a photovoltaic system, it is extremely important to properly consider the energy requirements of the heat pump.

4.1 The impact of the heat pump on energy demand

The energy demand of a heat pump depends on several factors, such as the temperature expected inside the building, the thermal insulation of the building and the efficiency of the heat pump itself. During colder periods of the year, when the temperature difference between the interior of the building and the environment is greater, the energy demand of the heat pump will be higher.

4.2 Ways to determine the power of a photovoltaic installation.

The selection of the appropriate power of a photovoltaic system for a heat pump can be done in several ways. One is to estimate the power demand of the heat pump at different times, based on the manufacturer’s data and the pump’s operating characteristics. Then the average daily energy consumption can be calculated and the power of the photovoltaic system can be selected on this basis.

Another way is to use monitoring of the heat pump’s energy consumption over a period of time. This will give you accurate data on actual energy consumption and, based on this, you can make a proper selection of the power of the photovoltaic system.

It is also worth mentioning the available online tools and calculators that can help you estimate the power of a photovoltaic installation for a heat pump. These tools take into account the parameters of the heat pump, geographic location and other factors to ensure the optimal power of the photovoltaic installation.


5 Photovoltaic installation price and return on investment

When choosing the right photovoltaic installation for a heat pump, an important factor is to evaluate the cost associated with the purchase and installation of the system. The cost of a photovoltaic installation can vary depending on a number of factors, such as the size of the system, type of panels, mounting technology and additional components such as optimizers.

It is important to take into account all component costs, including the cost of photovoltaic panels, mounting structure, electrical installation, assembly and any design and permitting costs. It is also worth paying attention to the quality and efficiency of the panels, as this can affect the total cost of the investment.

5.1 Potential savings

In addition to investment costs, it is also important to consider the potential savings that can be achieved by combining a photovoltaic system with a heat pump. The photovoltaic system provides free electricity to power the heat pump, which significantly reduces operating costs compared to traditional heating systems.

With this combination, the cost of purchasing electricity from the power grid can be reduced or eliminated altogether. These savings can be particularly noticeable during periods when the photovoltaic system generates more energy than is needed to power the heat pump and energy-intensive equipment, and the excess is returned to the grid.

5.2 Payback time

For a photovoltaic system with a heat pump, the payback time can be relatively short, especially if the price of electricity is high and favorable subsidies from government programs are available. The payback time can be several to several years, depending on individual conditions and system parameters.

When making an investment decision, it is advisable to consult a specialist who will carefully evaluate individual conditions, costs, potential savings and payback time. It is important to take into account current electricity price rates and possible changes in regulations and support programs for renewable energy sources.



  1. https://www.renewableenergyhub.co.uk/
  2. https://www.energy.gov/energysaver/heat-and-cool/heat-pump-systems/how-they-work
  3. https://www.seia.org/research-resources/solar-heating-cooling-and-hot-water
  4. https://energysavingtrust.org.uk/advice/heat-pumps
  5. https://www.solarreviews.com/blog/sizing-your-solar-panels-for-heat-pumps
  6. https://www.solarpowerworldonline.com/2019/08/calculating-solar-payback-period/
  7. https://www.energy.gov/energysaver/heat-and-cool/heat-pump-systems/geothermal-heat-pumps
  8. https://www.nrel.gov/analysis/tech-lcoe-re-cost-of-energy.html

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