Energy minister Paul Wheelhouse joined representatives from thermal energy storage technology firm Sunamp and Castle Rock Edinvar Housing Association at an event to mark the successful completion of Phase 2 of a unique project that is already cutting fuel costs for over 2,000 residents across Edinburgh and the Lothians.

With £3.2 million of funding from Scottish Government’s Local Energy Challenge Fund (LECF), the EastHeat project to install solar panels and trial heat storage batteries in housing association properties was completed on time and within budget, creating employment for up to 70 people.

It is estimated that gas and electricity fuel costs will be cut by at least £120,000 per year across the project, and homes fitted with Sunamp’s heat storage batteries will benefit from up to £300 savings on hot water and heatingbills each year.

Sunamp Heat Batteries efficiently store heat energy using low-cost, off-peak electricity, or ‘free’ electricity from Solar PV. They release the heat when needed to provide hot water or home heating, all without the need for an immersion heater or hot water tank and provide a unique and valuable bridge between legacy heating systems using gas boilers and zero-carbon heat from solar and heat pumps. The non-toxic heat batteries use a novel phase-change material developed with the University of Edinburgh to store three to four times more heat than hot water tanks of the same size.

On average the solar PV generates 2500 kWh per year of which about 1000 kWh directly reduces electricity bills by around £150 per home per year. The SunampPV heat battery, installed in these homes, is proving it can more than double the self-consumption of solar electricity via the heat batteries, dramatically reducing the amount of gas or electricity used to make hot water.

Mr Wheelhouse visited retired couple John and Margaret Murphy at their 2-bed terraced home in Newtongrange, fitted with solar PV and a SunampPV heat battery, to find out how the new technology is working for them.

The minister said: “This innovative project uses solar panels and heat storage batteries to cut fuel costs for hundreds of housing association residents. I am pleased to see the first part of this novel scheme reach completion here in Newtongrange and I wish Sunamp and Castle Rock Edinvar Housing Association the very best of fortune as their work to use innovation in energy storage to reduce fuel poverty continues.

“More homes and businesses across Scotland are seeing the benefit of renewable heat. New figures published by the Energy Saving Trust, on behalf of the Scottish Government, estimate that last year saw the largest annual increase in renewable heat output since measurement began in 2008 – up by over 1,100 GWh in a single year.

“There remains more work to do to reduce demand, supply heat more efficiently and increase the role renewable heat plays in Scotland’s energy mix. More than half the energy we use in Scotland is used to provide heat and that’s why we continue to develop new and existing avenues of support in this important area and this will be reflected as a key priority in our forthcoming Energy Strategy.”

Sunamp founder Andrew Bissell said: “We are super-excited that we’ve been able to work with our partners including Scottish Government, Local Energy Scotland and Castle Rock Edinvar to develop and deliver the world’s most advanced heat battery energy storage into over a thousand homes, increasing comfort and reducing bills. One of the aims of this project is to make sure it is replicable. We already have interested social landlords across the country who want to bring the benefits of heat batteries to their own tenants. We look forward to working with them.”

Castle Rock Edinvar head of property, Richard Jennings, added: “Addressing fuel poverty is a priority for us, as is the comfort of our tenants, and we realised we would have to be innovative in our approach if we are truly to have an impact. We are grateful to Scottish Government for awarding us grant support. Everyone involved stepped up to the challenge of delivering a large scale installation within a short timeframe and we are very pleased with the result. EastHeat has proved to be a highly replicable model that will allow social housing providers to meet the Energy Efficiency Standards for Social Housing.”

Energy efficiency improvements were made at a total of 1190 properties across Edinburgh, the Lothians, Falkirk and Stirling. In other parts of the project Sunamp replaced hard to control, costly electric heating systems (including night storage heaters) with comfortable, controllable radiator-based systems equipped with heat batteries to allow the use of cheap, off-peak electricity.