Living without radiators in Germany: How do we optimise the energy systems of the future?
Thomas and Heike live in a house without radiators. We visited them on a day when it was minus 0°C in Aachen, Germany. How do they do it? They live in a passivhaus. “The temperature is maintained thanks to powerful thermal insulation and controlled mechanical ventilation, which ventilates without having to open the windows,” explains Thomas Mokelbur. They heat their home with a heat pump that is partially powered by solar panels, weather permitting.
“Ever since I was young, I’ve dreamed of living in an efficient home, a house that used zero energy,” says Thomas. Living in a passivhaus means huge energy savings. They hisse five times less than an ordinary household.
However, his youthful dream not only benefits his pocket, it benefits the planet as well.
Buildings cause 40% of the EU’s total energy expenditure and 36% of greenhouse gas emissions. This is a figure that European projects such as the Urban Energy Lab 4.0 financed by the European Cohesion Fund, are trying to mitigate.
Developing new energy systems
At the Technical University of North Rhine-Westphalia in Aachen (RWTHAachen) a pioneering test bed infrastructure has been deployed to investigate the energy systems of the future and the interconnection between different components: users, buildings, energy systems and the electricity grid.
In the laboratory, they can simulate the climatic and energy conditions of a room or an entire city. “We try to understand the interaction between the user, their behaviour; the building envelope; the energy system and also the impact on the power grid to optimise the systems of the future and how to make them more efficient,” explains Rita Streblow, coordinator of Urban Energy Lab 4.0.
“Since we can’t bring a neighbourhood to our lab, we have to divide it up and study the actual components separately”. One of these components is the user. Often the more technical parts of the system or the building are analysed but the user is not involved.
The most notable test bed is the air-conditioned room which is monitored by an infrared camera. An experimental room – which can be transformed into an office, a living room or a bedroom – recreates the climatic conditions of a real building. It can be brought to extreme temperatures between 18°C and 45°C. Here they analyse the users’ needs and their interaction with the energy system depending on different scenarios.
What does the user do in response to their perception of cold or heat? If it’s cold, do they put on a jumper? Or do they put the heating up? This will impact their energy use.
The air-conditioned room has an intricate network of pipes to heat it. This is done via the laboratory’s own heat pump. They also look at how to make its design more sustainable.
Heat pumps will be the main technology of the future to heat our buildings, according to Christian Vering, coordinator of the heat pump laboratory. But they produce polluting emissions due to refrigerants. “The challenge is to use natural refrigerants but these are flammable, so we are analysing which fluid might work best.
Urban Energy Lab 4.0 also has a test bed to analyse how extreme weather impacts façade envelopes and how it affects a house’s interior. They also analyse the impact of energy systems on the electricity grid.
This project has cost EUR 5.5 million. 45% was financed by the European Cohesion Fund, 45% by the German Federal State of North Rhine-Westphalia, which contributed almost 2.5 million each, and the remaining 10% by German research institutes.
