The energy transition not only includes the expansion of wind power, photovoltaics and the like, but also the conversion of the heating supply. According to the German government's plans, around 14 per cent of heating energy is to come from renewable sources by 2020. However, this target is often pushed into the background at present - even though renovation rates are stagnating and outdated heating systems are driving up CO2 emissions considerably. A modern heating supply therefore means making a contribution to climate protection and reducing energy costs at the same time.
For bauverein AG from Darmstadt, this was a good argument for connecting the residential buildings owned by the company in Giessen to the SWG district heating network in 2013. "Many of the systems are no longer state of the art. The environment and our tenants would therefore benefit from a connection to the SWG district heating network," say Stefan Backmund and Eric Ackermann from bauverein AG.
Well developed and highly efficient
The new heating concept: around 850 residential units in 52 buildings - spread throughout the city - will have access to SWG's district heating network by 2013. SWG project manager Oliver Kisignacz comments: "Giessen has a very well-developed pipeline network, which we are constantly modernising and expanding. We can therefore connect the bauverein AG apartment blocks with little effort." The thermal waste and energy utilisation plant (TREA), which has already been awarded a special environmental prize by the city of Giessen, is one of the sources of heating energy. SWG has also been focussing on the expansion of combined heat and power (CHP) for many years. Combined heat and power plants produce heating energy for the district heating network and electricity at the same time throughout the city. CHP therefore enables a higher energy yield and energy efficiency than the separate generation of heat and electricity. "Heating energy from our district heating network is characterised above all by its excellent primary energy factor, i.e. the good ratio of primary energy used, such as natural gas, to the final energy supplied - heat and electricity," explains Oliver Kisignacz. It also reduces the costs for homeowners and housing associations such as bauverein AG, as there is no need to operate a heating system in the buildings.