Nearly two years ago, the Estonian Power Plants and District Heating Association started to recognise district heating networks with the Efficient District Heating label, which many of the networks in Estonia now have. This label shows that it is something of high quality and reliable, which will not disappoint. Of course, the reliability of a district heating network is one thing – the network could not function without it, as consumers need heating at any point in time. But how can we measure the quality of the network and energy? In addition to the affordability of energy, there are other nuances to consider.

A specific method to calculate efficiency

When it comes to energy, the keyword is efficiency and, as the name of the label implies, this is exactly what is assessed. The Estonian Power Plants and District Heating Association in cooperation with TalTech explored how to do this and developed a method to calculate the energy efficiency of district heating for the label.

The results were published in April this year in the reputable scientific journal Utility Policy in the article Promoting Efficient District Heating in Estonia, whose authors are Eduard Latõšov and Anna Volkova, researchers from TalTech, and Siim Umbleja, Executive Director of the Estonian Power Plants and District Heating Association. This label shows the consumer the efficiency of the district heating system used or the use of renewable energy sources, and focuses on the environmental friendliness, affordability and practicality of district heating.

The exact meaning of the label

The Efficient District Heating label shows a low energy carrier weighting factor in the network used, which is 0.9 for regular and 0.65 for efficient district heating. These factors are fixed and can be found in the Minimum Requirements for Energy Performance of Buildings Regulation.

The weighting factor of the energy carrier has three primary uses. Firstly, it is implemented in order to find the use of primary energy sources in energy production and the corresponding ecological footprint. The second option is to equalise the effects of various fuels and energy sources on the best technical solutions. The lower the consumption of primary energy, the more energy efficient the structures of the building’s technical systems will be. The third option is to use it to calculate the optimal cost level of the building’s energy performance. The optimal cost level leads to savings throughout the building’s estimated lifetime. Lower costs are decided by taking into account investment, maintenance and operating costs. A building with a lower consumption of primary energy probably also has lower life cycle costs.

The proportion of nearly zero-energy buildings must increase

In accordance with the European Union directive on energy efficiency, EU Member States are required to increase the number of nearly zero-energy buildings and, in accordance with the same directive, these buildings must primarily use renewable energy. There are approximately 200 district heating networks in Estonia, which cover more than 60% of heat production. Over the last 20 years, many boiler houses have been renovated and old gas and oil boilers have been replaced with ones using wood chips and with cogeneration plants. Wood chip makes a good fuel, as it is local and renewable, which makes the district heating sector carbon neutral.

Based on Estonia, supplementary data would not create too much extra work

TalTech’s research highlights the developments in the Estonian district heating sector caused by the Efficient District Heating label, as well as some setbacks which have occurred in relation to the use of the label. First off, it should be noted that the process of creating the label and introducing it to the district heating sector was quite long. The development of the label started in 2015 and it is fair to say that the work continued until 2018.

The bases on which a district heating network could be awarded the label in the first place were defined in the course of the label’s development. These conditions are:

• at least 50% of the heat must be produced from renewable energy sources
• at least 50% of the heat must be produced from residual heat
• at least 75% of the heat must be cogenerated heat, or
• at least 50% of the heat produced must be a combination of the above

The strengths of the planned solution are its strict abidance by the European Union legislation and the simplicity of the efficiency determination process, which does not require a lot of input data for verification. In the case of Estonia, the collection of supplementary data required for calculations would not create a great deal of extra work, as energy producers collect the necessary data themselves and submit them to the Statistical Office.

When will full climate neutrality be achieved?

The well-being of district heating networks depends on the well-being of customers, which is why inefficient and poorly maintained district heating networks have to make an effort to retain consumers, as, in accordance with the European Union directive on energy efficiency, they have the right to use more efficient and environmentally friendly local solutions instead of inefficient district heating. The latest trends rather indicate that the situation of district heating in Estonia is so good that many larger consumers, such as companies who have previously produced heat in local boiler houses powered by natural gas, are switching to district heating precisely because it corresponds to their environmental goals.

The Efficient District Heating label enables the district heating companies to increase consumer awareness and interest in fuels used to produce heat. The transition to climate neutrality is gaining momentum and considerable efforts are being made towards the goal of the European Union to achieve it by 2050. The Efficient District Heating label may help to achieve two goals of the district heating sector: to increase the energy efficiency of district heating, and to include more renewable energy in district heating. To that end, the requirements for obtaining the label may be gradually increased until we have a district heating system which is fully climate neutral and based on renewable energy. Fully climate neutral is, for example, a system which uses only residual heat or renewable sources to produce energy. In addition to district heating and district cooling, efficiency requirements have to be applied in the future to individual heating and cooling as well.

If you are interested, you can read more about the label on the website of the Estonian Power Plants and District Heating Association.