Breaking the Ice – Using ice as a renewable energy source

Mike Plaster
Tuesday 27th February, 2018

It causes chaos on our roads during bleak winters, but ice might just provide the answer to rising demand for green energies and the reduction of costs for consumers.

Last year, the UK made a breakthrough in a presumed first for a residential property when heating and refrigeration solutions manufacturer Viessmann installed an ice store system in a show home. It recovers energy from renewable sources to heat or cool buildings, as well as heating domestic hot water.

How does the energy storage system work?

The first-of-its-kind technology has been implemented at a Huf Haus sustainable demonstration home in Brooklands, Surrey. It uses a heat pump to take heat energy from water kept inside an ice store and heats or cools the building depending on the time of year. Here’s the science bit: the water temperature falls as more heating is required and more energy used, until it freezes. However, in this process, additional latent heat energy is released that can be collected, meaning the system can keep on taking heat from the ice[1].

Viessmann claims that an ice store covering a standard 10m3 for a detached house can generate a heat gain equivalent of roughly 100 litres of fuel oil, and can achieve 10kW of heating output. This process is also said to demonstrate 100% energy transfer, as there are no losses throughout[2].

During the summer months, the ice store acts as a natural cooling instrument for the building. In cooling mode, the ice – solidified now following the winter – is melted using heat which is drawn from the heating system through an extraction heat exchanger, and consequently cools the heating circuit within the home. But the ice store is also capable of drawing energy from the ground surrounding it, so if the ground has a higher temperature, heat is regenerated out of the winter heating period[3].

Water the benefits?

Up until recently, such technology wouldn’t have seemed out of place in a silver-screen sci-fi effort, but the fact is that while it might still be in its trial-and-error phase now, this is a very real, very achievable concept. This ice energy storage could be set to become big news.

Those in favour of the technology speak of its simplicity compared to standard geothermal systems, given that there isn’t the usual requirement for ground probes and excavation works – the tank isn’t buried deep into the ground, so there’s less chance of the complications that come with the installation of geothermal probes[4].

However, one of the biggest advantages of the ice storage cooling system is the sheer volume of energy it is capable of storing, and in such a limited space too, making it ideal for building plots with restricted space[5].  

The Ice Age

Are ice storage systems the answer to reducing energy consumption and easing the pressure on overworked power grids? It’s certainly a major leap forward in saving money (among households, but also eventually perhaps large companies), and is, of course, a huge benefit to the environment.

The UK in particular offers ideal conditions for such technology because of its climate and lack of deep ground frosts in winter[6].

A permanent move towards sustainable energies promises to have a hugely positive effect on the environment, namely in reducing carbon emissions. But the challenge now comes in making these energy storage technologies affordable for everybody, if it is to have a much greater impact.

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