Decarbonization and Faster Natural Gas Phase-Out for District Heating

as we continue to follow the stream of recently published scientific literature on district heating, we noticed a few major themes emerge in the last few weeks. For this issue of our newsletter we wanted to show that several recent papers address the theme of decarbonization and the corresponding policy frameworks. We found this theme very timely and relevant, so we will give you a quick overview of the cutting-edge research results for this topic.

Faster Natural Gas Phase-Out Strategies for District Heating

For a case study on Denmark, Siddique et al. investigated the Impacts of earlier natural gas phase-out & heat-saving policies on district heating and the energy system. They come to the conclusion that a faster natural gas phase-out until 2030 compared to other unrestricted pathways to carbon neutrality by 2050 only leads to a negligible cost increase (+ 0.07 %). The main enablers for this faster gas phase-out according to the study are a higher use of biofuels, increased electrification of the heating sector by using more heat pumps, and by expanding district heating networks.

Overall, the authors found such measures on the supply side more cost-effective than massive investments in building renovations to reduce the heat demand. While many of these findings are of course specific to the heating sector in Denmark, the case study, its employed methods and its conclusion can give important orientation also for the application to other countries.

A Comparison of District Heating Policies in Europe

And as decarbonization is a global challenge while the policies and local requirements differ from country to country, we think it is especially helpful to understand the parallels and differences between countries when it comes to their district heating landscape and their energy systems in general. Thus, we are happy to mention a new paper Policy frameworks for district heating: A comprehensive overview and analysis of regulations and support measures across Europe by Billerbeck et al. in this context. The paper compares the current district heating policy frameworks of 23 European countries and finds that they can be classified into 5 different groups with different levels of regulation and support for district heating.

For the example of Germany, the paper finds a high level of regulation regarding the consumer grid connections and a high level of support schemes for district heating, and medium level of regulation for ownership, prices, and metering. This puts Germany in the cluster "Regulate and Support" together with countries like Denmark, Austria and Italy, while e.g. Norway and Sweden fall into the category of "Regulate including Third Party Access and Regulate" whereas e.g. Great Britain, Spain and Finland are part of the cluster "Regulate and tax".

As one central conclusion, the paper shows that both in countries with high and low levels of regulation, it is possible to achieve high shares of green district heating by combining different measures and incentives. Of course, this shows that there is no one silver bullet or single best practice that could be easily adopted everywhere. Yet, we found this paper to give a very helpful overview of the current situation and different approaches to district heating policy in Europe.

Barriers and Opportunities for Cold District Heating and Cooling Networks with Heat Pumps and Storage

And to round up our overview of new papers concerned with decarbonization, we also found the paper District heating and cooling networks with decentralised energy substations: Opportunities and barriers for holistic energy system decarbonisation by Angelidis et al. to add an interesting perspective to the discussion. In this paper, the authors look into the important topic of how district heating substations including heat pumps and thermal energy storage in cold bidirectional heating and cooling networks can facilitate the sector coupling between heating, cooling, and electricity systems and thus support a general decarbonization process. In this study, the authors evaluate a comprehensive list of opportunities and barriers for the adoption of such systems based on both current literature and expert interviews. In this context, the authors consider systems in which the cold network provides both heating and cooling to the buildings.

As a key aspect for evaluating the feasibility of bidirectional district heating and cooling networks, the paper identifies the level of simultaneity between heating and cooling demands in the network. Furthermore, the paper stresses the challenges of efficiently controlling the hydraulic states of the bidirectional network but also mentions the opportunities of using the heat pumps as a source of flexibility for the electric grid. As a conclusion, the authors suggest building upon neighborhood scale systems with a limited number of prosumers to make best use of the opportunities and overcome some of the barriers to decarbonize district heating networks. One aspect we found especially interesting in this paper is the section based on stakeholder interviews, which adds valuable insights from different perspectives to the discussion of the scientific literature.

Further information

In addition to the theme of decarbonization we also saw several very recent papers with a focus on optimal control of district heating based on prediction and forecasting methods. While we did not cover this theme in detail in this newsletter issue, we found the following papers to be insightful and interesting:

• A comparison of prediction and forecasting artificial intelligence models to estimate the future energy demand in a district heating system
• Optimal management and data-based predictive control of district heating systems: The Novate Milanese experimental case-study
• Optimal control of a fourth generation district heating network using an integrated non-linear model predictive controller

The next issue of our newsletter will be published on March 1.