QUENTIN: Energy-efficient district development

The urban quarter of Tackenberg in Oberhausen centers of the project "District development based on local heating islands with flexible CHP systems and partial refurbishment" – QUENTIN for short. Energy-efficient and above all affordable living space combined with refurbishment concepts shall be achieved. Specifically, flexibly operated local district heating with CHP systems are built and investigated for four selected areas of the quarter.

The background to the project is the German government's energy concept. It calls for a virtually climate-neutral building stock by 2045. The key instruments for achieving this goal are the Building Energy Act (GEG) and the Heat Planning Act (WPG), which define standards for energy efficiency and the use of renewable energies. The challenge: as these standards can generally only be implemented at high cost, housing in the lower price segment with low rents is usually excluded from energy-efficient refurbishment.

This is where QUENTIN comes in: As part of the joint project, efficient, affordable concepts that can be implemented in the short term for the energy-efficient refurbishment of districts with a high primary energy saving potential are developed. The project partners encompass Energieversorgung Oberhausen AG (evo), Osterfelder Wohnungsgenossenschaft eG (GE-WO), Gemeinnützige Wohnungsgenossenschaft Oberhausen-Sterkrade eG (GWG), Servicebetriebe Oberhausen (SBO, a municipal enterprise of the city of Oberhausen) and Fraunhofer UMSICHT.

The project partners build on the results of the "FlexKWK" project completed in 2019, in which a new combined heat and power (CHP) concept was developed for an existing heating network in Oberhausen-Barmingholten: a combined heat and power plant, a large heat storage unit and an electric hot water generator supply in total 150 residential units. This has turned the estate into a flexible local heating district. Electricity is produced when it is needed. The resulting heat is stored and made available according to the requirements of the heating network.

Such local heat islands are set up for four selected quarters of the Osterfelder Wohnungsgenossenschaft and Sterkrader Wohnungsgenossenschaft housing association. This process is accompanied by the construction of low-temperature heating networks with central and decentralized heat storages, the refurbishment of selected buildings and the integration of public buildings of the SBO into the supply concept. At the same time, comprehensive analyses of the renovation status and primary energy reduction are carried out and renovation strategies are developed to evolve transferrable refurbishment concepts.

Two local heating islands with the originally planned concept went into operation in 2021 and 2022. They were planned to be as adaptive as possible to react to changing conditions. This means that the generously dimensioned heat storage units allow decoupled electricity generation by the CHP and heat consumption in the district. In future, the heat network provides an equally high degree of flexibility for electricity-based solutions such as power-to-heat or (large-scale) heat pumps. Therefore, the electricity can be drawn from the electricity grid at low-cost times and the heat generated can be taken from the storage systems when required. This system cushions rising prices in the energy sector and takes advantage of increasingly fluctuating electricity prices in the future (electricity price volatility).

In parallel, further development scenarios were created as part of the project. Although the natural gas-powered CHP local heating island was the more efficient technology at the time, further steps on the path to greenhouse gas neutrality had to be considered. At the start of the project this was already clear, so scenario-based operation optimizations were planned. The results of the calculations in the scenario horizon up to 2045 allow the following conclusion to be drawn: climate-neutral solutions are available for local heating districts. These even perform better in terms of the operating costs determined in the scenarios.

• Energieversorgung Oberhausen AG
• Osterfelder Wohnungsgenossenschaft eG
• Gemeinnützige Wohnungsgenossenschaft Oberhausen-Sterkrade eG
• Servicebetriebe Oberhausen – Eigenbetrieb der Stadt Oberhausen (SBO)

The project "District development based on local heating islands with flexible CHP systems and partial refurbishment" – QUENTIN for short – is funded by the Federal Ministry of Economics and Climate Protection.