In order to further anchor climate protection in the urban area, the municipal utility Baiersdorf (SK-B) commissioned eta Energieberatung to carry out a project study at the end of 2017. For the local secondary school and surrounding buildings (including residential buildings) it had to be shown how a sustainable heat supply can be set up in a heating network.
eta Energieberatung carried out an energy efficiency study on the properties and technical facilities of the ZMS. Within the scope of this investigation various energy saving potentials could be identified. The individual measures were analysed with regard to their technical feasibility and the economic efficiency.
Within the framework of the project, it was possible to identify possibilities for energy savings amounting to more than 700,000 euros per year. These range from purely organisational measures to larger investment measures such as the use of a CHP unit or the retrofitting of recuperators in the painting booths.
Among other things, it could be shown that the use of a natural gas cogeneration plant makes it possible to reduce heat production costs. A further interesting measure is the hydraulic connection of the two cooling networks in order to be able to use mainly the more effective chiller for cold generation.
The aim of the study was to develop various measures to reduce energy costs. Among other things, this resulted in approaches to reducing energy and costs by means of an energy supply via micro gas turbine. The waste heat utilisation of the thermal post-combustion failed due to the high costs of the conversion measures and the low service life.
Possibilities for energy savings in the amount of 13.5 million euros per year were identified. These range from organisational measures to larger investment measures such as the realisation of a natural gas CHP. Measures with immediate or short-term amortisation alone have a savings potential of 6.5 million euros per year.
The analysis of the existing cogeneration plant showed that the operation of the natural gas cogeneration plant is still economical. The use of biomethane would make ecological sense, but is currently not economical. The production of cold from the absorber is only recommended if the heat comes from the CHP. In addition, an electricity/natural gas tender was carried out.
The overall concept includes the complete renewal of the hot water and steam boilers as well as the integration of a CHP unit with connection to the staff dormitory and the conversion of the sterilisation to external steam. The existing cooling capacity is no longer sufficient for the planned extensions. A renewal is inevitable in the medium term.
An economic comparison of different heat generation technologies has shown that the conversion to decentralised hot water generation with natural gas low-temperature boilers was more economical than refurbishment or replacement investment in the waste wood heating plant. In addition, a natural gas CHP plant was installed to cover the company’s own electricity requirements.
