Since the end of 2016, renewable heat has been flowing in the community of Hallerndorf in Bavaria, Germany. Thanks to the good and trusting cooperation between the community of Hallerndorf and NATURSTROM AG, the local heating project could be implemented very quickly: Only 1.5 years elapsed between the initial contact and the heat delivery. Apart from Mayor Torsten Gunselmann’s commitment to bringing a sustainable solution for local heating to his community, various information events for citizens organised by NATURSTROM helped making this project a communal success.

Innovative technology concept with regional raw materials

The required heat quantity of 3 million kWh per year is generated by an innovative combination of different technologies. This ensures efficient capacity utilisation and a reliable supply to the connected households. The regenerative technology saves a total of almost 230,000 litres of heating oil per year.

Three different sizes of modular biomass boilers with an output of 155, 300 and even 550 kilowatts (kW) operate in the boiler house. Boilers are added depending on the heat requirement. This ensures that neither too much nor too little heat is available and that heat losses remain low. Franconian wood chips from the region are used. The operating company obtains the wood chips within a radius of 40 kilometres from surrounding municipalities and from the local forest owners’ association.

In the course of the construction measures, NATURSTROM laid empty pipes for the glass barrel extension in addition to the local heat pipes, so that no further civil engineering costs will be incurred in this regard at a later date. Hallerndorf will be able to benefit from this high-performance fiber optic infrastructure in the future.

Bavaria’s largest ground-mounted solar thermal power plant in combination with a local heating network

Unique for Bavaria: With an area of 1,304 m² in combination with a local heating network, the solar thermal system realised directly in front of the energy control centre is the largest in Bavaria. In summer, the system makes the most important contribution to Hallerndorf’s heat supply by converting the sun’s energy into heat for hot water and heating. In combination with an 85,000 litre buffer storage tank, the system ensures that no biomass is consumed during the summer months. The solar coverage share is 25 % of the total hot water and heating demand.

Flexibility through buffer storage

A buffer storage tower with a large capacity of 85 m³ enables flexibility in heat supply. In particular, the heat from the solar thermal system can be temporarily stored and made available in this way, even if the sun is covered by clouds.

Solar power for the boiler house

A photovoltaic system with an installed capacity of 26 kWp was installed on the roof of the boiler house. The electricity generated on the roof covers a large part of the power requirements of the energy control centre. Surpluses are fed into the grid, flow into the electricity storage with a storage capacity of 12 kWh or supply electricity for the electric car charging station in the yard of the boiler house.

E-car charging station in the yard of the central heating plant

The boiler house is located in the valley by the mountain Kreuzberg, a popular destination for excursions with beer cellars. NATURSTROM has therefore thought of something special for the design: The central heating system and solar thermal system should be as appealing as possible to passers-by and blend harmoniously into the landscape. The green yard invites visitors to rest and is intended to inspire citizens and excursionists for the energy transition. Since April 2017, citizens have been able to recharge their electric cars with green electricity directly at the energy control centre.

Awarded by the Sustainability Council and the Renewable Energies Agency

The joint commitment was rewarded by the German government in 2017: The German Council for Sustainable Development awarded the title “Project Sustainability 2017” to the local heating project in Hallerndorf. This prize is awarded to projects and communities that make an exemplary contribution to achieving the sustainability target by 2030. In October 2018, the Renewable Energies Agency also honoured the commitment with the “Energy Municipality of the Month” award. Hallerndorf shows how living climate protection works at the community level.

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