Wetenschap - 14 november 2013

Ultra-coldroom replaces energy guzzlers

Albert Sikkema

Clustering freezers saves hun­dreds of thousands of euros.
Heat captured for use in offices.

It does not seem too complicated. You just replace a large number of local energy guzzlers with one central, well-designed facility. That can be pretty lucrative, as they now know at PSG, where the new Radix Polaris freezer centre is delivering annual energy savings of around two hundred thousand euros. Tijs Breukink came to open the new coldroom officially on 5 November.   

Freezers are necessary in plant sciences as researchers are constantly working with DNA, plasmids, proteins and other materials that need to be stored at -80 degrees Celsius. Until recently the department had hundreds of different freezers, spread around the building. The freezers produced heat as a by-product, which meant they had to work even harder to keep the materials cold. That gobbled up energy.

Hence the idea of creating a freezer centre, a series of freezers in a separate coldroom, whereby the heat produced by the freezers is captured and channelled away for reuse in heating offices. The people behind the centre, Arjo Meijering and Sjaak van Brugge, had to figure out how to do this themselves because there were no examples in other research institutions. They developed Radix Polaris in partnership with Van den Berg Koeltechniek. ‘This is innovation that came from the workers,’ said Tijs Breukink. ‘It’s all about smart combinations of existing applications.’


The freezer centre is replacing 34 old freezers, which in itself saves two hundred thousand euros a year in energy costs. And Polaris also reduces the risk of downtime. In the past, freezers would break down occasionally. Such faults had to be detected and dealt with within four hours as otherwise the plant material would have to be thrown away. The freezer centre has much better insulation and the temperature will only rise above the critical level after five days. It also has sensors that flag a fault immediately.

PSG has got the bug now and wants to build some smaller versions of Polaris to replace the remaining freezers. Ton van Scheppingen, director of operations at PSG, has ambitious targets for energy saving: he wants the sciences group’s gas and electricity consumption to be halved by 2018. That will require more sustainable innovations, including in the greenhouses behind Radix.