Storing Heat Energy from Renewable Sources

Redesigning heating systems by using excess heat energy from summer, and improving the logistics around efficient use of excess heat from a steelworks

35 t
Est. annual reduction in carbon
emissions (tonnes CO2 eq)

A handful of energy – Salt In Matrix (SIM) heat storage materials
The SHED – Solar Heat Energy Demonstrator, Margam, South Wales
Waste Stream at Tata Steel Port Talbot

Our story

Dr Jonathon Elvins, Swansea University
When people think about renewable technologies, the images conjured up are of solar panels, wind turbines and electric cars. The next generation of heating has not been prominent in the public consciousness over the past 15-20 years, but this is changing with the current surge in interest in the climate change agenda, and a shift in government focus. The future of heating is now coming to the fore in both a technological and political sense. Heating accounts for approximately 37% of carbon emissions in the UK and therefore the decarbonisation of this area can have a significant impact upon the global climate change targets.

We will always need heating, particularly in the climate we have in the UK and at peak usage we use 4½ times more heat energy than electrical energy. However, gas supplies are running low and most viable alternatives utilise electricity - which we currently do not have the capacity for.

Therefore we are looking for a way to provide low Carbon space heating. Our research activities are focused on the storage and reuse of heat using a simple composite material known as salt in matrix (SIM). The materials are non-toxic and utilise simple chemical reactions to store heat energy in a simple, yet efficient manner. These materials, and the system surrounding them can be coupled with traditional heating options (such as gas, LPG etc) or renewable sources to store excess heat energy when not it’s required and deliver it back as space heating on demand.

Our ultimate goal is to be able to store excess energy from summer, generated via renewable solar thermal systems integrated in buildings, and then use that energy when required during the winter to warm the building occupants. Research activities are spread across multiple technology readiness levels with laboratory scale research focused upon optimising materials through to full scale building demonstrations at the SPECIFIC IKC SHED (Solar Heat Energy Demonstrator). Components are readily available and cheap, hence the cost base for storage is quite low and development is ‘future proofed’.

Alongside these developments, we’re working on a large project called MESH (Mobile Energy Stored as Heat), funded through the IDRIC (Heriot-Watt University) and Flexis (Cardiff University) programmes in partnership with University of Birmingham and Tata Steel. We are looking to develop materials to capture the waste heat produced by Tata Steel UK at Port Talbot Steelworks, Trostre Steelworks in Llanelli, and Shotton Steelworks, Deeside.

Typically, Tata is very proficient at utilising its waste heat. However, there are some elements which are too expensive to capture using current technology, or the available energy levels are not usable in an efficient manner. So, our materials can potentially capture those elements which are not being utilised and supply that heat elsewhere for space heating.

Our advice

Before starting, we looked at research activities outside the UK, at Boreskov Institute of Catalysis and TNO in Holland; and in the UK, the work of Birmingham, Nottingham and Loughborough Universities. These groups had a lot of interesting research on the fundamentals which got me intrigued and stimulated my scientific curiosity. Having said that, it’s sometimes the really simple things that draw you in.

The first time I mixed a salt into water and it generated heat, it showed me both the simplicity and effectiveness of the concept. This is a hook that I’ve used multiple times to get both scientists and non-scientists interested in the work we are doing. You need to demonstrate its effectiveness and potential - let people actually see it in use. They need to believe that the systems are relevant, working well and can have a serious effect on the decarbonisation of the UK. It’s good to get feedback on how they think the system would potentially work in their houses, and to provide information to them on how we think it will work.

Also, take the opportunities when they arrive. We should build on the current swing in favour of renewables and get the younger generation interested in science and technology - the kids in school and universities.

Our team has grown from four at the start to ten currently. Over the years, my recruitment approach has changed to ensure that the technical understanding and team dynamic are both equally important. The benefit of having a group of people that are willing to work together is massive, this approach aids with problem solving and has definitely accelerated our developments.

Our metrics

  • Provision of heat without the use of a gas supply (or other traditional source!)
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