Heat transition rethought: fact checking and more at the Berlin Energy Days

Anselm Laube: Municipal supply in existing buildings via low temperature

Anselm Laube took up this point. For the managing director of the Ludwigsburger Energieagentur LEA e. V. association, an efficient heating network is only possible with efficient houses. Only when building efficiency is taken into account, a district heating network can be operated at lower temperatures and thus be efficient and renewable.

Anselm Laube demonstrated how this can be achieved in practice with a pioneering project for municipal heat planning in Steinheim an der Murr. There, a supply concept is being realised via a new low-temperature heat network. The special feature: it is a low-temperature supply in an existing building - not as usual in a new building. A local supply network that works with low temperatures saves significantly more resources. Among other things, the project recorded savings of almost 40 per cent in electricity consumption by heat pumps and an almost 20 per cent higher yield from local solar thermal systems. This is made possible by a clever conversion of the existing buildings in terms of drinking water supply and space heating by enlarging the heating surfaces.

Dr. Lars Dittmann: Three important levers for the climate path in the building sector

Dr Lars Dittmann, Head of the Climate-Neutral Building Stock Department at Vonovia SE, moved in a much more homogeneous ownership environment. The housing company manages numerous small and larger neighbourhoods throughout Germany. In his presentation, Dr Lars Dittmann talked about the Group's heat transition strategy and its successes to date. In this regard, he mentioned three key levers:

1. Continuation of comprehensive energy refurbishment measures in the building stock
2. Replacement of conventional heating systems with hybrid systems and heat pumps, the installation of photovoltaics on all suitable roofs and the development of local heating networks in the neighbourhoods.
3. Close exchange between housing companies and the energy suppliers to jointly promote the conversion to CO₂ -free district heating and green electricity.

For Lars Dittmann, heating grids and heat pumps are the key to the heat transition in densely built-up areas. District heating is an important topic for all building efficiency classes in Vonovia's portfolio. Where the technology is not an option, the company plans to use heat pumps. As far as Vonovia is concerned, Lars Dittmann is optimistic about the heat turnaround. The Group has already decided to focus on renovating existing buildings - with success: renovation rates of up to 3 percent have been achieved so far. In this regard, the speaker emphasised that this always requires an individual consideration of the neighbourhoods. All possibilities had to be explored in each case. This includes, not least, keeping new technologies on the radar screen. Lars Dittmann briefly discussed an in-house research project for testing power-to-H₂ plants, fuel cells and storage technologies. Finally, he mentionned the challenges that exist in particular with regard to the expansion of heat pumps and grid connections. Here, the expert would like to see an orchestrated, clear procedure. At present, neither the implementation deadlines nor the costs could be planned.

Stefan Schwan - Creativity, Resilience and Efficiency

The closing speech of our panel at the Berlin Energy Days 2023 was given by Stefan Schwan from ENGIE Deutschland. As a concluding impulse, the Business Unit Manager Energy & Facility Solutions clarified one aspect: three decisive success factors for the heat turnaround.

1. Creativity: The conversion to green heat requires creative ideas - in the selection and use of technologies. Today, the building sector has a wide range of options for a sustainable heat supply. There is no such thing as an "off-the-shelf solution". So, down to the level of individual buildings, it is necessary to weigh up what is technically correct, up-to-date and economical in the long term. This requires creativity and modern concepts such as cold grids, the use of waste heat or geothermal energy.
2. Resilience: Stefan Schwan reminded that the outbreak of the Ukraine war last year showed how important it is not to become dependent on foreign countries for energy supplies. Sustainable solutions ensure price stability and independence. This includes producing energy partly or completely locally - either by oneself or with experienced partners.
3. Efficiency: Stefan Schwan sees efficiency as the third success factor. According to the expert, this is a fundamentally decisive aspect of the energy transition for ENGIE. Energy efficiency is always the first topic that ENGIE tackles in cooperations. This is because potential savings in existing buildings form the ideal basis for developing solutions for green heating as well as cooling, electricity and mobility. Optimisation measures, modernisation, but also digitalisation are decisive.