DTU develops new tools for energy savings

Europe is facing a deep energy crisis, and we all have to use electricity and heat in a fair-minded way and by saving wisely. This makes the results from the just-ended project, Smart Cities Accelerator + (SCA+), even more relevant.

For two years, DTU Compute, together with DTU Construct and eight other partners i Denmark and Sweden have collaborated with the development and testing of innovative tools and methods that make electricity and heat production more climate-friendly and energy consumption in buildings as efficient as possible - and in ways, that involve citizens in the green energy transition. The project has created a number of solutions and new knowledge that benefit the green transition.

In SCA+, DTU Compute has developed a prototype of a data-driven tool that makes it easier for operators and planners to see where the heat comes from and how it disappears in blocks of flats. The tool acts a bit like a kind of x-ray vision through the layers of the building, and thus provides useful information before deciding on a possible energy renovation. On a daily basis, the tool can be used to control the indoor climate.

The tool has shown that many radiators were set incorrectly in the social housing Taastrupgaard in Høje-Taastrup Municipality. It will benefit the climate and the heating bill for tenants, if the radiators run better. Similarly, the landlord can save money because the housing association today receives a penalty bill of DKK 500,000 annually from the district heating company because the return water from the housing area is not cooled enough. Too high a return temperature means that the heat is not utilized well enough and at the same time damages the efficiency of the large boilers at the district heating plant.

Here, it would make sense if the local heating operators could gain access to regulate the heating system in the individual apartment physically or digitally and limit the maximum and minimum flow in the radiator, so the radiators are neither blazing hot nor completely cold, DTU concludes. Landlords sometimes experience a tenant shutting off the heating to save money, but this increases the risk of mold. At the same time, the radiators in the other apartments have to warm extra to maintain the temperature because the one next door is cold.

Need to control the temperature better in apartments

"With the high prices for energy, it is important to have systems that can be used to save energy and thus reduce the climate footprint. At the same time, it must be done in a way that respects a good indoor climate. On the basis of the SCA+ project, we will be able to give advices on the great potential that lies in energy savings in the housing sector, which is responsible for approximately 40% of the total energy consumption in Europe," says Professor Henrik Madsen.

It resonates with the social housing administration company KAB.

"The results of SCA+ are very interesting, not least in light of the current energy crisis. The data-driven tools (IoT sensors) have shown that more than half of the radiators in the case properties were not set optimally in relation to the supply from the heating system. There are opportunities to save energy and reduce the CO2 footprint, which we will pursue. The potential of locking the temperature within a range is interesting, and even though it is currently against the legislation, we are in a situation where we want to encourage the politicians to turn over all stones," says deputy director Lone Skriver.

A digital twin, new heat pumps, and a concept for local shared heat supply

DTU has a large number of other results from the project. Together with the Centre for Mathematical Sciences at Lund University DTU Compute has developed a simulation model (digital twin) of the district heating system in a building. The digital twin will help to control the district heating better in an economical and climate-friendly way.
  
DTU Construct has contributed to the development of an indoor climate app for municipalities to check up on the indoor climate in schools. And the researchers have developed a tool to help municipalities and energy advisors when they have to calculate the economics of switching from a gas boiler to a heat pump. A relevant issue in both Denmark and Sweden.

The partner Lyngby-Taarbæk Municipality next to DTU has developed a new concept for local, shared heat supply for areas that are too far from the district heating network to be connected. In the concept, the utility company is responsible for the operation and administration of the solution. This setup has the potential to become a product at utility companies in both Denmark and Sweden.