Sixty experts from Sweden, Denmark, Germany, and Austria gathered for a two-day workshop at KTH Royal Institute of Technology to reflect on the challenges posed by the energy transition, especially for the electricity grid.
Most of the participants at DigiSect 2024 were researchers in the field of electric power distribution, but many also had deep knowledge in computer science and control engineering. A few with a background in district heating also participated.
The main theme of the presentations and discussions was the challenges that already exist and that will, in particular, result from the transition of electricity production that will have to be carried out over the next few decades, on the one hand to replace fossil electricity production with, mostly intermittent, new energy sources, and on the other hand the increased electricity needs that the decommissioning of fossil-based energy systems entail.
Interesting concrete examples from Hamburg (local electricity distribution network) and Vienna (district heating) were presented.
In Vienna, it is planned to replace the current production of gas-based cogeneration with mainly geothermal energy, which is hoped to be extracted from warm layers of the earth about 3000 m underground. As the existing district heating system requires a supply temperature of up to 145 ⁰C, the challenges of feeding this from heat pumps are extensive. In addition, the transition will entail the decommissioning of existing local electricity generation from CHP.
Hamburg is already having problems expanding the local electricity system and new customers are regularly turned away. It is considered virtually impossible to bury all the new electricity lines in the urban environment that would be required to switch the city from gas heating with current usage patterns. Instead, it is hoped that new load balancing solutions will replace the need for increased distribution capacity. Very high hopes are thus placed on radical changes in consumption patterns and energy efficiency in both housing and industry.
These two, probably fairly typical, European cities thus face formidable challenges. Although the situation in Sweden is significantly better, with largely fossil-free electricity and district heating, a transition to electricity in industry and the transport sector will not be easy. Here too, radical changes in building usage patterns are likely to be required to cope with the new increased electricity for industry as well as for transportation, i.e. the thermal storage capacity of the building stock will have to be used to shift electricity use to times when capacity is available in generation and distribution networks.
It is fortunate that these researchers are helping us to find the new digital solutions that will be required. There will be no shortage of fundamental challenges for us all going forward.