In the south of Germany a small district heating network has been installed in the town of Mietraching/Bad Aibling. The main sources of district heating are a woodchip boiler, mainly used in cold days, and solar collectors, mainly used in the warm days. The solar collectors are connected to centralised and decentralised buffer tanks for energy storage. Furthermore, a gas installation is delivering peak load for in mid-winter. The district heating network supplies heating to about 130 households, 2 schools, office buildings and a hotel.
Matosinhos’ year-round mild weather makes the challenge of decarbonising heating and cooling drastically different from more demanding climates, be it from a business-case as well as from a technical perspective.
Residential heat demand has historically been low. It is expected that the improvements in the building stock will essentially result in an increase of the indoor temperatures, which are low, and therefore will contain any pressure to increase the demand.
The growing services sector and still significant presence of an industrial sector further support them as the clear targets to address in terms of renewable heating and cooling.
As the district heating system in Herten is currently supplied with heat from coal-fired Combined Heat & Power (CHP), the approach was to frame a potential alternative mix of centralised heat supply units with a high share of renewable energy sources. It is aimed at designing a system which is technically feasible and to compare it to the current system with regard to the heating costs.
The village Büsingen, located in the south of Germany, has a 100% renewable heating district. In winter the biomass boiler delivers most heat, while in summer the solar park takes over as main producer of heat. A rapeseed oil boiler is available for peak loads.
In 2008, the Regional Municipality of Bornholm decided to become a 100% sustainable and CO2-neutral society in 2025, in which only sustainable and renewable energy is used. In 2019, already 60% of the island’s energy is produced fossil-free by using wind, sun and biomass power. The island’s green vision, big share of renewable energy, citizen and community involvement and replicability of the energy solution helped in winning the 2019 RESponsible Island Prize.
Southern European hospitals have high cooling and heating needs during the whole year. Combined district heating and cooling networks are, therefore, an interesting application. There are approximately 7,154 hospitals in Europe. Every hospital has considerable cooling needs and the excess heat from the cooling system can be captured and used in heat networks. Considering a conservative potential waste heat recovery tertiary buildings, up to 10 TWh year of heat could be supplied from this low-carbon source. The ReUseHeat project worked on an interesting application in hospitals in Madrid.
The ENTRAIN project aims at improving the capacities of public authorities to develop and implement local strategies and action plans for enhancing the use of endogenous renewable energy sources (RES) in small district heating (DH) networks. As part of the project there have been set up five initial surveys and local action plans for a specific region. The outcomes of the Regional Action Plan for Friuli Venezia Giulia are briefly described.