by Linda Bertelsen
Warming up - the innovation boost on district heating systems in the Netherlands

The innovation boost on district heating systems in the Netherlands

By Frits Verheij, Senior consultant energy transition at TNO, and Program Director of WarmingUP

A large consortium has joined forces in a Dutch Innovation Plan 2020-2022

The Dutch Climate Agreement targets 1,5 million fossil-free – ‘natural gas free’ – houses and other buildings in 2030. That’s about 20% of the total existing stock. Half of these are expected to be connected to a district heating (DH) system. The result would be a growth from 340,000 houses at the end of 2018 to more than a million in 2030. How to get there?

Three challenges drive the need for innovation

Three challenges for district heating in The Netherlands have been driving the development of the Innovation Plan WarmingUP. Firstly, upscaling to 80,000 houses (weq) annually in 2025 and 1.2 million in 2030. This is a big challenge for the heating industry and others involved in this transition in the built environment. The second challenge is to develop renewable heat. The target is a CO2 emission level of 18,9 kg/GJ, 70% lower than the average emission of heat boilers in 2018. Today’s level is about 50% lower. The third and last challenge is cost reduction to enable a business case at a larger number of locations in The Netherlands. This is translated into an annual improvement of 1.5% this decade.

Starting conditions for WarmingUP

To tackle this combination of challenges requires a joint effort of all key players in DH systems. As a result of this starting condition, a unique consortium was formed during the first half of 2019; see the next section. The challenges also made clear that a systemic approach to the Innovation Plan WarmingUP is needed. It should fulfill the strategies, targets, and interests of district heating companies, developers and operators of renewable heat sources, municipalities, grid operators, construction industries, and others involved. The results of the research and knowledge development should be such that these can be implemented in the daily activities of these organisations as of 2023 at the latest.

A unique consortium

A very diverse group of private companies, public organisations, and research institutes – 38 participants in total – has developed a 3-years innovation plan combining their innovation agendas and ambitions. A growing number of supporting partners – 18 at present – have joined this consortium, providing specific expertise, experience, data, knowledge dissemination platforms, and/or a financial contribution.

Experts of all participants are actively involved in the execution of the innovation plan for various reasons. Participants get a better understanding of each other’s need, practical experiences provide input and guidance to the research, and the R&D is focused on practical use. Although the advantages are clear, cooperation needs time, respect for each other’s views, and willingness to create joined solutions that might differ from your preferences.
The ecosystem of WarmingUP comprises 38 participants and 18 supporting partners, covering the full chain of district heating in The Netherlands.

Governance of the innovation plan

The budget of the Innovation Plan WarmingUP is € 19 million, of which 50% is funded by the Dutch Energy Agency RVO via theMission-drivenMulti-annual Innovation Program (MMIP) of the Top Consortium of Knowledge and Innovation in the Built Environment (TKI Urban Energy).
About 200 experts are working on one or several projects within the six themes. To execute this innovation plan effectively, a governance structure with senior managers and groups of senior experts is in place next to the standard project management.


Of course, you need to have consumers of DH at short distances from renewable heat sources. Besides, DH systems applying renewable sources should be technically feasible, financially viable, and societally desirable or at least acceptable. Therefore, the innovation plan is built in six coherent themes covering heating grids and system integration, sustainable heat sources, heat storage, and the societal aspects of district heating. These themes comprise 32 projects.

The innovation plan is built in six coherent themes

Figure 1. The innovation plan is built in six coherent themes.

The goals of WarmingUP are derived from the challenges, i.e., upscaling, applying renewable heat, and cost reduction. More specifically, the goals are:

Innovation and cost reduction of heating grids:

  • Design heating grids and system integration;
  • Large-scale and cost-effective installation of heating grids;

Unlocking the technical potential of sustainable heat sources, reduction of costs and risks, and optimisation:

  • Aqua thermal energy
  • Geothermal energy
  • Subsurface high-temperature heat storage;

Implementation with care and public support:

  • Socio-economic and societal integration of collective heating systems in the built environment.

First results at a glance

WarmingUP delivers a diverse pallet of results. This includes technical results, e.g. a design tool for district heating using multiple sources and managing different temperature levels, and new construction methods for heat pipe. Next to these a number of non-technical results will be delivered, e.g., standardization of (cost) indicators, financial and cooperation arrangements, analyses on the changing roles in the heat chain, behavioural analyses and also takes up new bottlenecks and R&D questions in innovation agendas.

A snapshot of the first results:

  • The alfa2-release of the WarmingUP Design Toolkit is tested by engineers of district heating companies and grid operators as well as by technical experts of consultancies. This toolkit is developed for the design and daily operation of future-proof district heating systems, e.g., involving low and medium temperature heat sources, and large-scale heat storage. This should save more than 25% in operational costs and create more flexibility in the design of heating grids.
  • First part of a measurement campaign to predict the reduction of the supply temperature. The lower the temperature, the lower the costs of heat supply.
  • A web viewer on aqua thermal energy. With this viewer, it is easy to identify how much heat from aqua thermal energy can be gained, in what locations, and at what costs it can be supplied. A first spin-off is that the calculations of the aqua thermal potentials have been included in the models of the Netherlands Environmental Assessment Agency.
  • Unlocking a larger volume of geothermal resources now is possible thanks to the development of a map of shallow geothermal reservoirs suitable for low temperature production (Brussel’s Sand).
  • An inventory of high temperature heat storage capabilities, including feasibility studies on technical, economic, spatial planning and legal aspects. Based on these analyses a selection has been made of three pilots for testing large high-temperature heat storage systems, combining geothermal system development in shallow and marginal reservoirs.
  • Insights through market research into the factors that determine residents’ support for the transition from heating with natural gas – about 95% of the houses in The Netherlands – towards a connection to a district heating network. The report also provides guidelines on how municipalities or heat suppliers could deal with this.
  • Analysis of various archetypes of cooperation between district heating companies, municipalities, and citizens’ collectives from initiative to realizing a district heating network.
  • Overview of the most promising possibilities for demand-side management in district heating networks, including the result of market research on the willingness of residents to participate and the financial benefits for heat suppliers.

Dissemination of our results

To enable upscaling and acceleration of the collective heat transition, new knowledge is developed in this WarmingUP value chain, and is directly applicable in the day-to-day practice. Companies and governmental institutions deliver experiences from practical cases that are used to gain technical, financial, and social information. This information is enriched and processed to new scalable results and standards that can easily be applied to other locations. Cooperation in projects, thus, is a very effective way of sharing knowledge and experiences even in an ‘online world.’

Reports and new knowledge are disseminated by the website WarmingUP.info, through webinars, interviews and by videos. There are several network organizations involved in WarmingUP to contribute to knowledge dissemination to specific target groups, also outside the WarmingUP community. They support in organizing webinars and help with the transfer of the reports to practical manuals and visuals.

Two large events with various workshops have been organized to stimulate interaction between participants and partners and to use each other’s expertise for specific topics and R&D questions. So, a mixture of communication tools and activities are used to disseminate results and share the latest insights as shown in the infographic.

Last but not least, an ‘explanation’ video has been made to explain the value of smart design and ditto operations of district heating systems integrated with renewable heat sources and heat storage, see https://youtu.be/xrPCmpUxEAI.

What’s next

At present, most of the activities as well as the communication is in Dutch. As various European relationships of the WarmingUP community show interest in the results of our innovation plan or even want to become a partner, more reports or at least the summary of these will become available in English in the future.

Another development will be the application of a combination of R&D results in demonstration projects, starting in less than two years from now. Information on more than 50 potential locations has been gathered. A selection process has started to end with at least four locations later this year: two based on low-medium temperature networks, and two with medium-high temperature networks. Preparatory activities for these demonstration projects are scheduled for 2022.

Finally, this should show that DH systems can run on sustainable heat sources and still are reliable and affordable for users, technically feasible and economically viable for investors and contractors. Our system approach should also show that future DH can be designed and operated cost-efficiently and coherently.

For further information, please contact: contact@warmingup.info

“Warming up – the innovation boost on District Heating Systems in The Netherlands” was published in Hot Cool, edition no. 2/2021. Download and print the article here.
Warming up - the innovation boost on District Heating Systems in The Netherlands, HC no. 2-2021

Meet the author

Frits Verheij
Senior consultant energy transition at TNO, and Program Director of WarmingUP