Heat from the outside air can be used to heat buildings through the use of a heat pump. These work by the same principle as pumps using heat from the ground. At the end of 2017, 394 thousand air-source heat pumps and 55 thousand ground-source heat pumps were in use in the Netherlands.
Most heat pumps absorbing heat from the outside air are connected to air heating systems, which are often integrated into cooling systems (air conditioning units). Increasingly often, however, air-source heat pumps are being connected to systems extracting heat from a water source, especially in private homes.
|Connected to air heating systems (x 1,000)||Connected to water heating systems (x 1,000)|
Reduction in fossil energy consumption
The utilisation of open air heat means less burning of natural gas to heat indoor spaces. Conversely, heat pumps also consume electricity which, for a large part, is generated using fossil fuels. On balance, air-source heat pumps led to a reduction in fossil energy consumption amounting to 900 terajoules (1 terajoule equals 1*1015 joules) in 2017, i.e. 30 percent more than in 2016 and double the amount in 2015.
|Avoided fossil energy consumption due to open air heat utilisation (terajoules)|
Negative balance of avoided CO2 emissions
When offsetting CO2 emissions due to electricity generation for heat pumps against avoided emissions as a result of less burning of natural gas, the balance is slightly negative. In other words: the current mix of fuels and combustion yields involved in generating electricity leads to slightly higher CO2 emissions than would have been the case if natural gas was burnt in a boiler.
Little known on actual energy performance of heat pumps
The reduction in fossil energy consumption and the avoided CO2 emissions strongly depend on the energy performance factor of heat pumps. To determine this factor, CBS uses a fixed number based on a European guideline. Little is known about the average energy performance of heat pumps in practice in the Netherlands. As such, levels of fossil energy reduction and avoided CO2 emissions are highly uncertain.
Report on renewable energy 2017
Last Friday, CBS published its annual report on renewable energy and developments in the area of heating, electricity and transport. This publication presents a structured outline of the myriad of figures available on this topic.
Already in May, CBS reported that the share of renewable energy in total energy consumption increased from 6.0 percent in 2016 to 6.6 percent in 2017. By far the largest source of renewable energy is biomass; consumption rose by 8 percent in 2017. Energy consumption from solar and wind power increased by 31 and 15 percent respectively last year. Consumption of geothermal and aerothermal energy rose by 13 percent on average.
Renewable energy is used to generate heat, electricity and for transport. In 2017, nearly half of renewable energy consumption was used for heating, 43 percent for electricity and 9 percent for transport. Consumption for heating and electricity was approximately 10 percent down on 2016. Consumption of liquid biofuels was up by around 30 percent.