Battery-related concerns are increasingly in the spotlight — but modern BESS are designed to be exceptionally safe, reliable and efficient. In this blog, we put those concerns into context, explore how they inform choices for smaller-scale, behind-the-meter BESS installations, and ask: how can customers benefit from understanding grid-scale insights – and know that we’re already ahead of the game?
Battery Energy Storage Systems (BESS) are a crucial part of the UK’s energy transition, helping businesses and the grid store renewable energy, maintain power resilience, and optimise energy efficiency. The Clean Power Action Plan anticipates a huge increase in the need for battery storage – from 4.5 GW last December to 23-27 GW to meet its 2030 targets. Much of this growth will come from grid-scale batteries, with small-scale BESS playing an important role. At the same time, public awareness of lithium-ion battery safety is increasing, especially around fire safety.
The batteries used in BESS
This June’s House of Commons Research Briefing, by Georgina Hutton and Iona Stewart, notes that lithium-ion batteries account for more than 90% of grid-scale UK installations between 2020 and 2024[1]. These can be subdivided into lithium-ion-phosphate (LFP) and lithium-nickel-manganese-cobalt-oxide (NMC), with LFP accounting for approximately 60% of the UK market in 2022 due to lower costs and greater efficiency. In these batteries, energy is stored and then discharged: positively-charged particles of lithium ions move from the cathode to the anode, where they are stored while the battery is charging. When needed, these ions move back to the cathode, releasing electricity to the grid or to a specific device. This cycle occurs continuously, making lithium-ion batteries efficient, reliable, and ideal for both grid-scale and behind-the-meter applications.
A 2022 research paper, examining the challenges facing grid-scale battery storage, explains how lithium-ion BESS incidents can occur: if a single cell catches fire and is not properly insulated from the rest of the battery, it can trigger a chain reaction known as thermal runaway, which leads to adjacent cells catching fire[2]. If a part of the battery is damaged or faulty, decomposition produces heat, leading to further decomposition, further heating, and – without sufficient cooling mechanisms in place – this can result in fire.
However, this doesn’t mean there is a high level of risk. In 2023, The Faraday Institution found that only one in 40 million battery cells in operation experience the level of failure that leads to fire[3]. So while battery-related fires occasionally make headlines, they are extremely rare in properly designed BESS.
Battery safety in context
While media coverage of battery fires has increased, it’s important to put the numbers into context. Business insurer QBE made a FOI request in May this year to UK fire services. The headline stats seem worrying: at least three lithium-ion battery fires per day requiring fire brigade attendance – a 93% increase from 2022 to 2024[4].
But, behind this top line, this rise largely reflects the growth in EVs and electric scooters, and the general ubiquity of lithium-ion batteries in everyday use – such as smartphones and laptops. And this domestic use and possible misuse may have led to the exponential rise in battery-related fires:
- Incidents involving e-bikes have doubled from 2022 to 2024, with an e-bike fire nearly every day
- E-car fires rose by 77% during the same two years (though the volume of e-cars more than doubled in this period)
- E-scooters and electric mobility scooter fires grew by 32% and 20%, respectively
- Electric scooters have been banned on Transport for London’s network, with the risk of £1,000 fine for non-compliance[5].
Related, the UK Parliament Research Briefing authors raise potential concerns over ‘second-life batteries’ – generally from EVs – being used in BESS units. They note a recently-commissioned government study that suggests,
“Second-life batteries could pose a greater risk than new batteries because they could have experienced damage or contain cells from different sources, which could result in electrical failure.”[6]
Grid-scale BESS – lessons learned
Grid-scale incidents involving BESS are extremely rare, but can provide valuable lessons. While the UK has seen two recently-documented incidents of BESS fires: a fire in Liverpool in September 2020 and one at a project under construction in Essex this year, the Electric Power Research Institute (EPRI) observes that BESS design has improved since the installation of the Liverpool BESS in 2018,
“the overall rate of incidents has sharply decreased, as lessons learned from early failure incidents have been incorporated into new designs and best practices.”[7]
By applying these lessons, behind-the-meter BESS installations are safer, more reliable, and better optimised for efficiency. Advanced design, digital modelling, and rigorous testing ensure potential issues are identified and resolved before commissioning.
Causes of grid-scale BESS incidents
The good news is these insights directly inform best practices for behind-the-meter BESS, helping installations be safer, more reliable, and efficient.
In a 2024 white paper, EPRI collated insights from their BESS Failure Incident Database as an analysis of the root causes of failure. Although cause could not be determined for many incidents due to a lack of historical information gathering, they considered a range of causes in their report: design; manufacturing; integration, assembly & construction, and operation. The white paper also considers failed elements: cell/module; controls, and balance of systems (BOS) – e.g. busbars, cabling, enclosures, fire suppression systems, transformers and HVAC.
The analysis shows that integration, assembly, and BOS components are the most common areas where attention is required. EPRI notes:
“Integration is the most common root cause of BESS failures, and the vast majority of incidents with this classification involved BOS components. These components included DC and AC wiring, HVAC subsystems, and safety elements such as the fire suppression system. Lithium-ion BESS contain components from multiple suppliers, which are not necessarily designed to work together. Integration is a critical part of the deployment and installation process to ensure all interfaces are compatible and functional.”[8]
Crucially, these findings have already informed industry best practices. Modern BESS designs incorporate robust thermal management, high-quality fire suppression, and meticulous commissioning to ensure all components work seamlessly together. EPRI further highlights that as BESS deployment grows, training, quality control, and adherence to best practices are key to success:
“As deployment increases, many more individuals and organizations are working on BESS for the first time. New products without long operational histories are entering the market… Global storage deployment is expected to grow exponentially, and many new entrants to the industry are expected. Sufficient training for manufacturers and integrators/developers and more extensive product quality control systems are needed to prevent integration, assembly, and construction failures going forward.”[9]
For behind-the-meter BESS, this means that working with experienced experts ensures installations meet the highest standards, combining lessons from grid-scale deployments with meticulous design, testing, and integration processes.
How does this relate to behind-the-meter BESS technology?
Research and development continues at the large-scale, grid-scale needed to meet both the global demand and, more locally, the UK-wide demand to achieve the storage capacity needed to meet the Clean Power Action Plan.
But UK manufacturers, data centres, hospitals – generally, large sites and/or energy-intensive businesses – need to maintain power resilience and maximise the benefits of investment in renewable energy assets. These businesses may already rely on BESS as a critical energy management asset, or they may be considering it as a means to improve energy efficiency and flexibility; to maintain power resilience in the event of disruptions to grid supply, or to help reduce emissions and improve sustainability.
Why choose Powerstar for behind-the-meter BESS?
As behind-the-meter BESS experts, Powerstar design, manufacture, install, and maintain our own bespoke units, with a power range from 50 kw to 10 MW, and capacity range of 200 kWh to 20 MWh. Our business processes, combined with UK design and manufacture, demonstrate our commitment to ensuring the highest safety standards, and the reliability and efficiency of our BESS solutions for customers across the UK.
Seamless integration
Where integration issues are a major issue at the grid-scale, at Powerstar we work with customers to ensure their behind-the-meter BESS integrates into their existing infrastructure, seamlessly.
Feasibility study: This the first step in our process – to mitigate risk, evaluate internal and external factors, and ensure that a BESS is the optimum investment for your business.
Digital twin stress testing: Where we create a digital twin of your site, we can then assess how a BESS might perform under a range of conditions, which means we can identify and address potential issues during the design stage of the project.
Grid emulators: We are one of a very few non-university entities with genuine grid emulators. This means that we can provide real-time, accurate grid supply simulations based on your specific project parameters and digital twin, ensuring precision in the commissioning process for your BESS project.
Conflict resolution: Through digital modelling, we can identify and resolve possible conflicts between your existing infrastructure and the installation and operation of a BESS.
Testing, quality assurance, and servicing and maintenance
Industry bodies – including EPRI – have observed the influx of newcomers into the BESS market. As a critical part of the energy transition, there is a clear demand for BESS. Whether at grid-scale or behind-the-meter, working with experts is crucial: for safety, for risk management, and to ensure the commissioning of safe, reliable, cost-effective and efficient assets that demonstrate a return on investment. Powerstar BESS units undergo rigorous testing, including specialised Factory Acceptance Tests (FAT) in our microgrid test bay. And each Powerstar BESS meets BS EN 62933-2-1:2018 requirements.
For optimal performance, we offer full maintenance and servicing support, including remote monitoring: instant alerts for errors; real-time equipment monitoring to detect any maintenance needs, and data to help identify performance improvements.
Achieving Net Zero – with tried and tested BESS technology
More than 20 years’ experience in providing energy management solutions, with British manufacturing underpinning all our core technologies, we offer the reassurance companies need when looking at behind-the-meter BESS: expertise in product design, materials, and assembly; expertise in integration, and ongoing support and monitoring.
BESS is a critical aspect of the UK’s Net Zero goals, both at grid-scale and behind-the-meter, and our expertise and commissioning processes help mitigate concerns around fire safety. Powerstar are experts in helping UK companies address their own agendas: more resilient power, greater energy efficiency, and higher cost-savings.
[1] https://researchbriefings.files.parliament.uk/documents/CBP-7621/CBP-7621.pdf
[2] https://advanced.onlinelibrary.wiley.com/doi/full/10.1002/aenm.202202197
[3] https://www.faraday.ac.uk/wp-content/uploads/2023/07/Faraday_Insights_17_July2023_FINAL.pdf
[4] https://qbeeurope.com/news-and-events/press-releases/fires-caused-by-lithium-ion-batteries-double-in-two-years/
[5] https://tfl.gov.uk/modes/driving/electric-scooter-rental-trial
[6] https://researchbriefings.files.parliament.uk/documents/CBP-7621/CBP-7621.pdf
[7] https://www.epri.com/research/products/000000003002030360
[8] Ibid, p.11
[9] Ibid, p.12
