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How UK weather conditions pose risks on Battery Energy Storage Systems

As battery energy storage systems continue to play a vital role in the UK’s energy transition, it is important to acknowledge the risk extreme seasonal weather patterns can pose on such projects.
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By Alastair Nicklin , 

Vice President, Power and Renewable Energy

28/08/2023 · 4 minute read

Battery energy storage systems (BESS) continue to play a vital role in the UK’s energy transition. However, extreme seasonal weather patterns can pose significant risks to BESS and require substantial planning and mitigation. 

BESS’ role in securing energy supplies

Beyond optimising wind and solar power generation, BESS can also enhance the grid’s capacity to deal with fluctuating electricity demand during the transition to green energy generation.

BESS developments are designed to provide an effective storage solution for excess energy generated during periods of low demand. Subsequently, this surplus energy will be readily available for when demand increases, providing operators with the financial incentive of receiving a higher price for stored energy. This fiscal benefit is boosted by the decrease in lithium prices witnessed over the preceding several years  ̶  making BESS projects an attractive option for utilities and developers.

However, similarly to any energy and power projects, there are various risk elements involved. Volatile and extreme seasonal weather conditions are a pertinent risk to BESS developments.

Seasonal weather risks and mitigation steps

Summer months:

During the summer months, higher temperatures can present added risks to BESS projects. While the longer, lighter days are great for other sources of renewable power generation, it can cause problems for energy storage.  Higher temperatures could potentially overwhelm the cooling systems within batteries to the point that they go into thermal runaway. In a worst-case scenario, this could lead to both fire and explosion  ̶  posing physical harm and financial risks to the operator and its employees.

During the summer months, you can seek to mitigate BESS risks through:

  • Regular monitoring of temperature, especially during heatwaves
  • Ensuring storage systems are free from humidity
  • Not charging/discharging BESS for safety during extreme heat
  • Assessing impacts to water supply during heatwaves and droughts
  • Minimising wildfire risk through vegetation management of areas surrounding BESS  ̶  especially in rural locations

Winter months:

Colder, winter months expose BESS projects to different risks. Sites become vulnerable to freezing, flooding, or excess moisture during this period  ̶  possibly leading to water reaching parts of the batteries that must remain dry. The resulting damage can be costly to repair and lead to thermal runaway events. 

During the winter months, you can mitigate BESS risks by:

  • Keeping the storage system ventilated and free of excess moisture
  • Ensuring the containers maintain a regular temperature
  • Clearing snow from BESS containers and the surrounding site as thawing snowfall can replicate the major flooding risks of heavy rainfall  
  • Establishing an intrusion protection (IP) rating of 5 or above for containers to ensure they are resistant to moisture

Further weather risks and mitigations

In addition to heat and cold extremes, heavy rain that causes flooding can threaten BESS sites. In anticipation of excessive rainfall during construction, it is prudent to ensure that all laydown areas of the site susceptible to flooding are sufficiently protected and mitigated. Additional drainage and flood barriers can also be installed to further offset the risk during the construction phase and throughout the project’s operational lifetime. For extra mitigation, the Flood Hazard Assessment provides important recommendations - using at least the 1-in-100-year flood level. As flood risk alters over time, it is critical sites review their defences periodically.

The threat of strong winds or storms also require regular checks to be carried out on BESS projects. It is crucial that construction equipment, transmission lines, nearby infrastructure, and geographical features  ̶  such as trees  ̶  are assessed to ensure safety at the site. More severe storms are a significant concern as steel-framed structures are at a heightened risk of being damaged by lightning strikes. Additionally, during some thunderstorms, hailstones  ̶  some over two inches in size  ̶  can cause serious damage to renewable energy facilities.

Next steps

BESS will continue to have a profound impact on energy systems in the UK, helping forge the path to carbon-neutral societies. However, without the right protections and mitigations in place, changing weather conditions could derail the ongoing energy transition. 

To find out more about how these risks may impact your business, reach out to your Marsh advisers.

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