A multi-award winning ice storage technology is to be used in an inner-city quarter of Nuremberg, Bavaria, to provide heating and cooling for an office building and adjacent complexes. Construction is underway at Quartier Hansapark Nuremberg on a vast ice storage tank – which has a diameter of 9.5 metres and a height of 5 metres – which is at the core of the self-sufficient, renewable energy concept initiated by the Munich-based te-group.

The relatively new technology has been in use in the housing sector since 2010 and has won over 40 different innovation and environmental awards. So how does it work? First local solar and ambient heat are fed into the water-filled storage tank, then a heat pump extracts the heat (to heat the buildings in the complex). As a result of the extraction, the temperature drops to freezing point. As the water crystallises, it releases energy (90 watt-hours per kilogramme of water) which is used for heating.

With a total volume of 300 cubic metres, the tank can generate the equivalent amount of energy as the combustion of 2,900 litres of oil in just one freezing event. Furthermore, in the summer months, the ice can be used to provide air conditioning. One of the main selling points of the technology is the substantial savings in CO2 emissions – in one earlier residential model it slashed them by 70 percent.

“We are very proud of the pioneering concept for the Hansapark quarter. It combines high energy efficiency with environmental awareness as well as attractive investment and operating costs…The ultimate goal in the implementation of our projects is to supply 100 percent of our energy from renewable sources," explains Stefan Keller, managing partner of the te group, in a press release. The tank itself is being built by the GETEC Group. The project has been financed with over EUR 27 million, most of which has been privately raised.