Berwickshire Housing Association Heat Battery Trial
The Berwickshire Housing Association Heat Battery Trial assessed the performance of innovative low-carbon technologies in domestic heating. It commenced in 2015 with innovative heating systems replacing a range of electric, gas fired and coal fired systems in seven homes, ranging from established to new built dwelling and from single bedroom to five-bedroom properties. It is believed to be Scotland’s first real-world demonstrator combining two low carbon technologies - air source heat pumps and heat batteries. These innovative systems remain in use today.
Demonstrating low carbon and lower cost heating for Scottish homes
A combination of an air source heat pump (in this case Daikin or LG) and a Sunamp phase-change heat battery replaced existing heating systems to demonstrate reduced carbon emissions and lower heating costs. Using the heat battery to store energy enabled the opportunity to change electricity consumption from peak to off-peak charging tariffs, which was a major contributor to reduced costs.
The benefits of the new system are:
— Reduced energy consumption and domestic heating costs for tenants
— Reduced fuel poverty
— Reduced carbon emissions from domestic heating
Further, the trial has enabled an innovative Scottish company to successfully demonstrate its low carbon technology.
Putting plans into action
The heat battery trial was developed by the Berwickshire Housing Association in partnership with Sunamp, the Edinburgh based developer and manufacturer of the innovative heat batteries. It was supported by grant funding from the Department of Energy and Climate Change under the Advanced Heat Storage Small Business Research Initiative competition.
The trial enabled Sunamp to successfully demonstrate the effectiveness of its heat battery technology and this has catalysed company growth. The company worked closely with the University of Edinburgh to develop its technology and the collaboration has benefitted the university through employment of four PhD students, seven work placements for undergraduate students and several master’s research projects.
Low Carbon Heat Technologies Used
Air Source Heat Pumps
These generate renewable heat by capturing low grade thermal energy in the air and then concentrating this energy for use as a heat source for home heating and hot water. The pumps are powered by grid-supplied electricity. In the trial, the pumps are used to provide low-carbon heat, either directly to the home’s heating system or to charge the heat battery.
Heat Batteries
Phase Change Heat Batteries store heat energy using safe, reliable and non-flammable proprietary thermal energy storage materials. The heat to charge them is generated, in this case, by an air source heat pump and is stored with very low heat loss for later consumption.
System Controls
Advanced controls, developed by Sunamp, run the heat pump during low-cost off-peak charging periods with the heat generated stored for later use. This reduces energy costs by avoiding operation of the heat pump during peak electricity charging periods, when electricity is most expensive.
How are Scottish low carbon heat and renewables companies benefiting?
The key beneficiary of this project are the householders, the landlords (in five cases this is a Housing Association) and Sunamp, which develops and manufactures its heat batteries in Scotland. Sunamp now employ 50 staff carrying out high value jobs.
The success of this trial has led to further developments of Sunamp’s heat batteries and, as a result, new opportunities. For example, in 2019 Sunamp was commissioned by West Highland Housing Association to supply an evolved version of the heat battery system, updated with Panasonic air source heat pumps and third generation UniQ heat batteries, to be installed as a retrofit in 145 homes to replace electric heating. In turn this led to 200 new homes having Daikin heat pumps installed for Highland Council.
This is just a fraction of the 10,000 heat batteries now made in Scotland and shipped by Sunamp, sold and installed by a network that includes leading Scottish distributors William Wilson and Scott Coppola; leading project and third sector organisation Warmworks; and installation companies including Everwarm, BRB, RM Plumbing & Heating, Merrimans and R&I Cruden.
The University of Edinburgh also gained significant benefits through its collaboration with Sunamp.
Benefits achieved
The combination of air source heat pumps, controls and heat batteries has delivered reduced energy costs and carbon emissions in all seven homes.
2013-2014
Carbon emission savings
— A 17 to 36% reduction in carbon emissions from domestic heating.
— Annual carbon emissions savings of between 1,259 - 3,634 kg CO2e per home.
For Users
— A 45 to 57% reduction in energy costs.
— A cost saving per home of between £325 to £926 per annum.
For Stakeholders
— Successful demonstration of innovative low carbon heat technologies in a domestic setting.
— Demonstration of the ability to move electricity consumption used for heating from expensive on-peak to cheaper off-peak tariffs.
— When replacing electric heating, a reduction in the total amount of grid-supplied electricity used to heat the homes.
— When replacing fossil fuels, a removal of the need to purchase fossil fuels.
— Lower levels of fuel poverty in the housing stock.
— Proved Sunamp technology could work in homes.
2019
Carbon emission savings
— Emissions further reduced, 95% down versus pre-intervention as a result of further decarbonisation of the electricity grid.
— As the electrical grid continues to decarbonise, the carbon savings achieved by these technologies will continue to increase.
For Users
— Cushioning users against the ongoing trend in energy price rises.
For Stakeholders
— Sunamp secured further equity investment and trials support of governments. (Scotland, UK, EU, USA DoE).
— Fully commercialised some key products.
— Scalability, performance and reliability proven in ~10,000 homes.
— Sunamp has OEM, MoU or Evaluation agreements with over 40 global organisations (including six in China; five in USA/Canada).
The project is being supported by the Scottish Government’s Low Carbon Infrastructure Transition Programme.
This case study has been developed with support from:
