Impact case study database

Figure 1. Timeline showing development of impact from the underpinning research described in Section 2 (blue lines/text refer to outputs referenced in Section 3) [S1].

Based on the new stable formulation of salt hydrate PCM developed by EaStCHEM Professor Colin Pulham, Sunamp Ltd has brought to market the world’s first commercially viable residential heat batteries, allowing the company to grow quickly to reach worldwide orders worth GBP50,000,000. In homes, Sunamp heat batteries maximise the use of locally generated renewable energy and off-peak electricity and increase energy efficiency, thereby reducing carbon emissions and saving households money. Installations in social housing properties have shown the particular benefit that heat battery use brings to residents at the greatest risk of fuel poverty, and given social housing providers a valuable, low-maintenance solution for decarbonisation.

Economic and commercial impact of the world’s first commercially viable PCM-based residential heat battery

Based on the patented formulation for SAT PCM [R4], originating from Pulham’s research, Sunamp Ltd has developed the world’s first commercially viable residential thermal energy storage systems (i.e. heat batteries). The company attributes this achievement in large part to the EaStCHEM research that allowed them to “ harness the potential of salt hydrates as a heat store”, confirming that “ Sunamp would not exist without Pulham’s research” [S1, p10].

Sunamp’s residential heat batteries [S2] (typical installation shown in Figure 2) provide efficient, high density heat storage with an advertised lifetime of over 50 years and at a cost that is competitive with conventional systems – all properties that stem from EaStCHEM research to enable the long-term stability of salt hydrate PCM and reduce its cost [S1, p4-5].

Figure 2. Sunamp heat battery (right), showing space saved compared to traditional hot water cylinder (left).

Since August 2013, Sunamp has grown rapidly from development of the early SunampPV model, primarily deployed in large UK trials from 2014 (1,000 units sold) [S1, p4] to full commercialisation of the UniQ model, available worldwide since 2018 (5,000 units sold to 12-2020, 20% beyond the UK) [S1, p9]. The resulting economic success for Sunamp includes the following [S1, p6-7]:

• Total investment of GBP12,000,000 raised

• Total revenue of GBP10,000,000

• A twelve-fold growth in orders between 2019 and 2020 – and a current order book worth GBP50,000,000, despite the impact of the Covid-19 pandemic. Major purchase orders have been signed with partner companies in the UK, Netherlands, France, Germany and South Korea (Figure 1).

• Agreement, in 2020, for the lease of a factory in South Korea, with an annual capacity to produce up to 60,000 units, which will meet initial demand from Asian markets.

Sunamp has created 52 jobs (headcount: 52; FTEs: 50) [S1, p8]. Economic benefit extends to more than 60 distributors, resellers and installers across the UK, along with partners in the UK, Europe and South Korea who distribute Sunamp products under their own brands [S1, p6-7]. Partner Fischer Future Heat confirms the technology as a “ must have” hot water solution, providing capabilities unique within the market and popular with customers, and credit its role in driving their business growth and maintaining a strong market position even through the economic challenges of 2020 [S3].

Grant funding of GBP7,700,000 to Sunamp, underpinned by further PCMs developed through Pulham research, has enabled the company to extend their technology into new applications [S1, p11]. These include automotive (business unit since 2018, developing heat management innovations for engine warm-up, cabin heating, and electric vehicle range consistency) and commercial/industrial applications (business unit since 2019, for greater control, reliability and security of supply and recovery of waste heat) [S1, p11-12]. Sunamp also worked with Pulham to respond to the Covid-19 pandemic; in 12-2020, Sunamp brought to market the Permafrost VacSafe, providing long-lasting -70°C storage for the distribution of vaccines [S1, p12].

Environmental and economic benefit through the use of heat batteries

For domestic users, Sunamp heat batteries provide highly efficient heat storage and enable increased use of locally generated renewable energy and off-peak electricity, thereby reducing use of conventional fossil energy sources and carbon emissions and saving households money.

Sunamp heat batteries greatly reduce heat loss compared to traditional hot water cylinders. Analysis of the emissions saved through this effect, across all devices installed to the end of 2019, shows that 4.6ktCO₂ have been saved as of late 2020 [S5, p9]. For each device, this is a saving equivalent to 26% of the UK annual per capita residential emissions [S5, p10]. Even taking into account the carbon footprint arising from manufacture of the heat batteries, all devices installed to the end of 2018 have achieved carbon payback and a net reduction in carbon emissions [S5, p9]. Reduced heat loss also saves homeowners money on bills – in trials, a saving of GBP67 per year for every household [S4, p6].

In homes previously struggling with inefficient heating from electric boilers and wet radiators, Sunamp heat batteries have delivered a steady supply of heat charged almost entirely with off-peak electricity [S4, p10]. This has increased comfort and reduced the need to overheat, resulting in 35% reduction in energy usage [S4, p32; S4, p79]. Sunamp heat batteries have also been installed in combination with solar photovoltaics (PV) to displace gas burn in a combi boiler, providing between 55-63% of hot water free of charge [S4, p10].

Ultimately, Sunamp heat batteries offer an energy-efficient, affordable and fully controllable route by which households can move to all-electric and renewable energy solutions, providing an immediate viable alternative to the use of fossil fuels for heat. They can be easily retrofitted to decarbonise heating in existing housing, and provide the enabling technology needed to introduce heat pumps to existing properties without excessive, costly and impractical insulation. With heating and cooling consuming almost half of total energy use in the UK, and more than 80% in every home, heat batteries can make a major contribution to reducing CO₂ emissions.

Reduced fuel poverty and operational improvements for social housing providers

Sunamp’s work with UK housing associations, which has seen heat batteries installed in 1,500 properties since August 2013 [S1, p6], has shown the particular benefit that heat battery installation brings to residents experiencing fuel poverty. Fuel poverty affects around 4.5 million households in the UK, with residents struggling to pay bills, unable to maintain comfortable temperatures in their homes, or unable to use heating or hot water at all.

Figure 3. Housing association resident and heat battery recipient Joan, who has noted valuable savings and increased comfort [S4, p20; S6].*

Testimony from residents who have received Sunamp heat batteries confirms the improvement to their quality of life: "It saves a lot of money, put it that way. You’re getting your hot water for free. Before that, this house was a really cold, cold house…It makes a lovely difference.” (Figure 3) [S6].

Castle Rock Edinvar housing association, who have had Sunamp heat batteries installed in hundreds of properties, confirms their significance as a “ genuine solution to fuel poverty” [S7]. The association has also seen multiple other improvements to their operations as a result of heat battery installation. Reduced heat loss helps them meet statutory obligations under the Energy Efficiency Standard for Social Housing. In addition, with both gas safety checks and legionella testing no longer required when heat batteries replace gas boilers and water tanks, money is saved as well as safety increased [S7]. This is a valuable contribution to mitigating the cost burden of compliance – their biggest growth area in expenditure [S7]. Castle Rock Edinvar also confirms the important influence that the availability of Sunamp heat batteries has had on their strategic thinking around decarbonisation, providing “ a solution for future legislation” and technology to “ disrupt our approach in a safe way” [S7].