Heat pump and photovoltaics - climate-friendly heating

Heating and central water heating are the main energy guzzlers in German households. Generating heat can contribute to up to 80 per cent of the total residential energy demand. An efficient heating system is, therefore, an important starting point for reducing climate-damaging CO2 emissions. From a climate policy and financial point of view, it makes particular sense to combine a photovoltaic system with a heat pump for residential heating systems.

Why are heat pump systems more efficient?

The primary energy values of energy sources such as oil, gas or electricity are calculated based on their calorific value. They cannot be compared directly with each other to determine their efficiency in heat generation for buildings. The primary energy factor (PFE) enables this comparison. It takes into account the amount of energy required by upstream process chains outside the system boundaries during the extraction, conversion and distribution of different primary energy sources. Electricity has a (non-renewable) PFE of 1.8. Natural gas and heating oil have a (non-renewable) PFE of 1.1 each. Looking only at the PFE value, it appears that fossil fuels are more efficient. A closer look reveals a different picture.

A heat pump heating system draws about 25 per cent of the total energy required in electricity as operating power to generate the heat. The heat pump obtains the remaining 75 per cent carbon-neutral from the environment. Natural Gas or Heating Oil heating systems burn 100 per cent of the energy source to meet the heat demand. If one now compares the PFEs of the different energy sources with the actual total energy consumption to generate the required heat quantity, the advantage of using a heat pump system is apparent.

Sample calculation:

Total annual heat energy demand: 20.000 kWh

Electricity for heat pump: 25 % of 20.000 kWh = 5.000 x 1,8 (PEF) = 9.000 kWh (total energy consumption)

Heating oil/ Natural gas central heating: 100 % of 20.000 kWh = 20.000 x 1,1 (PEF) = 22.000 kWh (total energy consumption)

Photovoltaic systems improve the life cycle assessment of
heat pump systems

The carbon footprint of heat pumps can significantly be improved by using renewable energy such as solar power for their operation. This set up has been widely adopted: One-third of heat pump owners also have a photovoltaic system installed on their roof.

However, besides the carbon footprint reduction, a photovoltaic system also saves money. Self-generated solar electricity is now cheaper than electricity purchased from your supplier. It, therefore, makes particular sense to use your solar power for the two biggest residential energy guzzlers, heating and hot water. A rule of thumb: Self-generated solar electricity can cover up to 45 per cent of the energy needs of heat pump systems. Best results are achieved in combination with a solar power storage system.

Use solar power efficiently with a heat pump and power storage

Solar power storage systems make solar power available independent of the sun. They store excess solar energy generated during the day for later use.  When the battery of the power storage unit is charged, the intelligent charge management system makes the excess solar power available to operate the heat pump. Conversely, the charge management system also ensures that the excess electricity is fed into the battery if the heat pump no longer requires to be powered.

Heat pumps with SG Ready-Label

What does the term 'smart grid' mean? It describes the communicative networking and control of power generators, storage facilities, electrical consumers and network equipment in power transmission and distribution networks for electricity supply. Modern heat pumps are equipped with an SG-Ready input.

The SG Ready-Label label is awarded to heat pump series whose control technology enables the integration into a smart grid (SG).  RCT Power power storage units, for example, offer multi-function relays to individually control additional consumers such as domestic hot water heat pumps. Switch-on or switch-off conditions are controlled via the RCT Power App. The flexible application and combination of heat pump and solar power storage will increase the efficiency of photovoltaic systems even more.  

Achieve a higher efficiency level for your house

A third benefit of the heating system upgrade - besides the energy cost savings and the reduced carbon footprint - is the considerable appreciation of the property value. Installing a heating system with heat pump and solar power storage will rank the house in a better efficient class.  

Better Carbon footprint, better efficiency class, lower energy costs - the combination of photovoltaic system, solar energy storage tank and heat pump is the intelligent way to generate heat.

Do you want more information? Just contact us.