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.
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.
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 2015 alone, around EUR 53 billion euros were invested in energy-efficient improvements. The German Government provides grants and low-interest loans as incentives. In 2016, German citizens saved almost EUR 500 per capita as a result of energy efficiency measures, putting them at the top of the international tables.
There has been a particular focus on replacing outdated heating systems and on switching from fossil fuel to renewable energy. In 1975, more than half of all German homes were heated with oil, compared with just over a quarter today. 60 percent of all new homes built in 2016 are heated with renewables. Solar energy systems, biomass heating and heat pumps that make use of ambient heat are already meeting around 12 percent of the demand for heating. And since 2000, the German Government has been subsidising the replacement of heating systems to speed up the switch.