This case study covers the investigation of renewable heat supply options for the new development area «Teilraum 31» in Ansfelden. The area is mainly owned by the municipality which, therefore, can define priorities regarding energy efficiency and renewable energy. The new development area could include ca. 120,000 m2. According to the current planning strategy, it will be used for different types of buildings – mainly residential ones, and could reach a plot ratio of 0,45 to 0,55 per building lot. The expected buildings consist of around 100 single-family houses, 200 row houses and 10 small multi-family houses.
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 city of Munich implements various policies to increase energy efficiency and to mitigate climate change. In 2007, the city of Munich realized the solar thermal heating project Am Ackermannbogen which includes 3078 m2 rooftop solar collectors, a seasonal storage tank & heat pump. The installation provides heating to 320 apartments, of which 40 – 45% solar thermal heat.
A farmer and engineer, Ulrich Bader, owns a biogas plant located close to the southern german village Vatersdorf. In 2012 he initiated and developed (with the help of a heat pipe manufacturer) a small scale district heating network to give a purpose to the heat released by the biogas plant. In combination with two wood-chip boilers and a fossil oil boiler Ulrich Bader can guarantee sufficient heating throughout the year to 85 households of the village Vatersdorf.
Dollnstein is a small community with about 2,700 inhabitants in the heart of Bavaria, Germany. Dollnstein is located in the Altmühltal Nature Park, one of the most popular touristic destinations in Bavaria. In 2011, the municipality has initiated and in 2013/14 installed an intelligent heating network for about 40 households and several communal buildings.
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.
Brædstrup Fjernvarme has during the last 10 years been a Danish frontrunner in how to make district heating efficient, cheap for the customers and environmentally friendly at the same time through activities in the electricity market, smart metering, introduction of regularly service visits by the customers and support to improvement of house installations, implementation of the worlds first large scale solar district heating plant combined with natural gas fired CHP, implementation of borehole storage, heat pump and electric boiler to be able to maximise flexibility in the electricity market. The result has been a natural gas reduction of 38%.
The Hjallerup district heating network delivers heating to 1982 consumers in the towns of Hjallerup and Klokkerholm. Originally 2 CHP units produced all heat necessary. Nowadays, also a solar system, storage tank and biomass plant contribute to the delivery of more sustainable heat to the two towns.
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.