***April Fools’ Day Alert***
Don’t worry, we are aware of the limitations of sugar based thermal energy stores, we’ll keep Andy’s sugary snacks for eating or handing out at conferences, not for thermal storage!
Breakthrough in energy storage
An Inverness-based engineering firm has attracted attention after outlining a novel approach to thermal energy storage using a proprietary material system developed in-house.
At a time when large-scale battery proposals at Essich and Torvean continue to generate debate, the team at 4c Engineering has proposed an alternative concept based on locally sourced, high-density phase change materials. The internal project, titled Gran’s Grid, centres on their new storage material referred to as Thermally Activated Bulk Latent Energy Transfer (TABLET) medium.
“We are aware of ongoing public concern around lithium-ion systems and wanted to explore credible alternatives using materials with established supply chains,” said Managing Director Andy Hall. “The TABLET medium offers a dense crystalline structure and a useful working temperature range. As a phase change material, it provides latent heat storage capability alongside sensible heat capacity, making it well suited to distributed heat storage applications.”
The Numbers Behind the Sugar Rush
4c Engineering has released eye-catching metrics for their prototype storage unit:
• Massive Payload: A standard 20ft container packed with tablet holds approximately 20 tonnes of the TABLET medium.
• Highland Heating: Using the tablet’s specific heat capacity (1.3 kJ/kg.K), one container holds approximately 1.5–2 MWh of thermal storage. Allowing for heat exchanger efficiencies that gives just over 1 MWh of usable thermal energy.
• The Household Impact: With the average UK home using about 11,500 kWh of gas per year, just one of these “Sweet Stacks” could provide a typical Inverness semi-detached house with over a month of heating.
The news follows a string of energy developments in the region, including plans for a Hydrogen facility at the Longman and ongoing debates over pumped storage hydro on Loch Ness. However, there’s still work to be done. “We are continuing to refine system efficiency,” Hall added. “Early-stage testing on prototype 01-04 identified unanticipated thermal losses associated with informal product sampling during cooldown phases. Mitigation measures are now in place.”
The company plans to pilot the first “Confectionery Kilowatt” unit near the Inverness Campus later this year—provided they can stop the staff and local students from eating the inventory.
Thermal storage TABLET prototype recipes 01-04
