Pleasantly warm, renewable and efficient

The success of the Energiewende also depends on reducing the energy needed for heating, cooling and hot water in buildings, as well as on the extent to which renewable energy covers the remaining demand. Heating accounts for over half of Germany’s energy consumption. Almost two-thirds of this is used for heating and hot water by the country’s 40 million households.

Reducing heating energy demand

Reduction targets for total heating energy demand

2,026 petajoules

were consumed by Germany’s 40 million households for heating and hot water in 2013.

This is why the German Government wants to reduce primary energy demand for oil and gas in buildings by 80 percent by 2050. To achieve this target, buildings must become far more energy efficient, while renewable energies must play a greater role in providing heat and cooling. The aim is that renewables will cover 14 percent of heating and cooling demand by 2020. In this way, Germany is implementing European targets. The EU’s current directive on the energy performance of buildings stipulates that all new buildings in Europe must be “nearly zero-energy buildings” from 2021.

Germany was quick to realise how much energy can be saved in buildings. As far back as 1976,the German Government adopted the first Energy Conservation Act and the first Thermal Insulation Ordinance in response to the oil crisis. Their provisions have been constantly updated and adapted to technical advances. Under the Renewable Energies Heat Act, it has been compulsory for all new residential buildings to cover a minimum share of their energy demand through renewable energy since 2009. This can be achieved by using solar thermal energy to support a gas or oil-fired boiler or installing a renewable energy heating system, such as a heat pump or a pellet boiler.

How much energy is consumed in buildings?

Share of total final energy consumption in Germany

New buildings consume only a tenth

Annual heating consumption in litres of oil per square metre of living space for different types of buildings

However, 70 percent of all residential buildings in Germany are over 35 years old – in other words, they were built before the first Thermal Insulation Ordinance was adopted. This means that many buildings are not properly insulated and are often heated by old boilers and fossil fuels such as oil or gas. An average German household consumes around 145 kilowatt-hours per square metre of living space per year for heating, the equivalent of some 14.5 litres of crude oil. Highly efficient new buildings require only a tenth of this amount. Primary energy demand in old buildings can be reduced by up to 80 percent by making energy-efficiency improvements and switching to renewable sources. This requires better cladding insulation, new building components, modern heating and cooling systems, and better control technology. In 2013 alone, around 55 billion euros were invested in energy-efficiency improvements. The German Government provides grants and low-interest loans as incentives.

The focus is on replacing old heating systems and switching from fossil fuels to renewable energies. In 1975, oil was used to heat over half of the apartments in Germany, but this has now fallen to under a third. Most of the 650,000 new heating systems installed in 2013 were gas (77 percent) or renewable energy (18 percent) systems. Solar thermal energy plants, biomass heating systems and heat pumps that use ambient heat already meet around 12 percent of heating demand in Germany. The German Government has been providing incentives since 2000 to speed up the replacement of old heating systems.