Today’s energy outlook highlights the need to use available resources more sparingly than in the past and to take further measures to ensure the efficient use of energy. The heating of buildings offers substantial untapped energy saving potential.
In countries with high heating requirements such as Germany, heating accounts for over three quarters of private households’ total energy consumption and for almost half the energy consumed by the service sector.
Despite technological progress, the demand for space heating, especially from private households, has hardly declined in the past years, which is partly attributable to the strong increase in living space and the number of single households.

While other sectors characterized by high energy requirements – such as the industrial and manufacturing sectors – have been forced by strict environmental legislation and international competition to exploit available efficiency potential, energy efficiency is only gradually beginning to play a role where the heating of buildings is concerned. As a result, this is where the European Commission’s Action Plan for Energy Efficiency sees the greatest potential.
According to EU estimates, new strategies and the intensifi-
cation of existing efforts can reduce the EU-wide consumption of primary energy in residential buildings and commercial buildings by approx. 27 % and 30 %, respectively, by the year 2020.

This target can primarily be achieved by improving the energy quality of buildings and their heating systems.
Besides modern thermal insulation, efficient heating systems with intelligent control systems offer the best possibilities for conserving energy. Obsolete heating boilers consume up to
30 % more fuel than modern heating systems. According to the Federal Association of Chimney Sweeps, there are over one million oil heating boilers and more than 650,000 gas heating boilers in Germany that were installed before 1983 and have a much lower energy efficiency than modern boilers. The replacement of these boilers would reduce not only the consumption of fossil fuels but also private households’ heating bills.

Opportunities offered by renewable energies in the heating sector

Systems for the use of renewable energies can make an important contribution to sustainable energy supplies. According to the Federal Association for Renewable Energies, they accounted for 6.2 % (98.3 billion kWh) of Germany’s total heating energy consumption in 2006, compared to 5.9 % in 2005. Wood log and pellet systems have made the biggest contribution so far.

The Federal Association estimates that approx. 590 billion kilowatt-hours of heat can be produced from renewable energies by the year 2050. Solar energy as well as biomass and geo-
thermal energy are expected to show the strongest increase.
According to the Association, the development potential of renewable energies in the heating sector has not been fully exploited yet – geothermal and solar energy, in particular, could be used to produce much higher quantities of heat.
To facilitate the use of renewable energies for the heating of buildings, energy policy needs to provide strong incentives which have a consistent and long-term effect.