District Heating: Not a hottie, but I’d still do it

When it comes to the energy transition of Leiden, it is vital to explore new ways to heat the city without gas, the good old gas that has been something oh so convenient, but also deceptive. It has betrayed Leiden, and many others. Now it tries to explain things for the better: “Come on, carbon capture and storage will fix this. And how about condensing boilers?! Hey, at least I am not as bad as oil and coal!”

But Leiden has started to realise that it needs to look for a new source of warmth. Now it seems that the best bet for Leiden is to opt for―no matter how unsexy it sounds―an extensive district heating network. Others, like many cities in Denmark, have already fallen in love with it.

Simply put, in a district heating system heat is distributed in the form of water or steam from the site(s) of production to a wide range of users. The system, like any other, has its pros and cons. A top-down imposed centralized system might raise objection, and the initial changes needed in the infrastructure will be costly. Nonetheless, a district heating system would offer substantial long-term benefits for Leiden.

District heating systems are energy efficient and highly flexible as they can utilize various sources of heat for optimal energy use.

To start with, surplus or waste heat from different processes could be pumped in the network. For instance, cogeneration plants that produce both electricity and heat (for a network) are significantly more energy efficient than conventional thermal power plants that merely waste the by-produced heat. Surplus heat can be connected to the district heating network from various local, or more distant sources, such as the Rotterdam harbour. Using waste or surplus heat would result in significant total energy savings, which is positive for the environment, and perhaps even for the wallets of the Leidenaars.

Apart from waste heat sources, the system can be fed by almost any current (and likely future) heat production forms. Some of the renewable examples are geothermal heating, biomass, central solar heating, and various types of heat pumps that can harvest heat from air, ground and water. In Duindorp, for instance, the district heating is fed by warmth harvested from seawater.

District heating system’s flexibility and compatibility with different forms of heat production makes sure that Leiden will not be dependent on only specific sources of energy. This, in turn, provides energy security. In order to make the district heating system even more flexible, it is recommended to pair it with (seasonal) thermal energy storages that act as a buffer and solve the intermittency problem of certain renewable energy sources. The storages can also help to optimize the energy efficiency of the system and its financial returns.

In short, it is time for Leiden to leave its smelly old gas system and move on. District heating—even if it remains unsexy—is a perfect fit for Leiden in its longevity and adaptability. It will open endless possibilities to keep the city warm and cosy—now, and in the future.


Photo: Bill Ebbesen

Sources and further reading:

State of Green: New White Paper on District Energy

The Guardian: Lessons from Denmark: How District Heating Could Improve Energy Security

Sustainable Cities Collective: The Heat is On for Sustainable District Heating and Cooling

UNEP: District Energy in Cities

The Energy Collective: Holland: Pioneering Sustainable District Heating Innovations

Review of District Heating and Cooling Systems for a Sustainable Future

Towards Next-Generation District Heating in Finland

The ADE: What is District Heating?



5 thoughts on “District Heating: Not a hottie, but I’d still do it”

  1. I don’t know if district heating opens up endless possibilities, but I think you make pose some striking arguments for changing towards a district heating systems. While still acknowledging certain flaws within the system. Do you think it can also work for smaller villages and places that are more remote?


    1. I think this depends on the density of the village, to start with. In the village where I’m from, in the middle of nowhere in Finland, a district heating system would not make the slightest sense because there are few houses in a large area. A lot of heat would be wasted in a heating network. It’s better if everyone has their own system (which is hopefully as sustainable as possible), such as ground or water sourced heatpumps, biomass boilers/burners etc. In little Dutch villages, which tend to be quite compact, a district heating system might make more sense. (Emphasis on MIGHT. Don’t trust me, I am not an engineer.)


  2. I agree that district heating in general is a very efficient way of cutting your carbon emissions as a city. However, I was wondering whether building the needed district heating plants and all the new piping to connect houses with the plants won’t exceed the financial possibilites of a small city like Leiden with limited financial resources.


  3. Thank you for your clear explanation about district heating Emmi. I only have one remark on the seawaterheat power plant in Duindorp. It was a revolutionary idea but the temperature difference was too little to really make it work. Also the heat transmission between the warmer seawater and the colder surface water is problematic because they can not mix otherwise it would corrode the pipelines. All with all it was a nice pilot but it was not feasible at all. Because of these reasons they stopped the project a while ago. But it still can be nice initiative, only the temperature difference between the seawater and the surface water has to be bigger.


  4. I like the idea about district heating a lot. I also really enjoy the way you write, personifying gas really caught my attention. I agree with you that this system could be a good alternative to gas.
    I do have a few questions. The system will cover a bigger area than just the municipality of Leiden, and the heat will be transported by water or other fluids (correct me if I’m wrong). Where does this water come from? Do you think that at some point it would be possible to have a national heating system? Finally, what do you think will be the biggest objections by civilians?


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