A renewable energy company was installing a 50MW Battery Energy Storage System at the UK’s largest onshore windfarm to help balance supply and demand on the energy network. Battery Energy Storage Systems, or BESS, store surplus renewable energy and release it when demand rises, helping to balance the grid and maintain network stability.
Project summary
| Organisation | Renewable energy company |
| Asset | Battery Energy Storage System (BESS) |
| Capacity | 50MW |
| Scope | Sealing of transformer cable entry points |
| Solution | NOFIRNO® Duct Seal System |
| Completion | May 2022 |
As the UK continues its transition to low-carbon power, assets such as BESS are becoming increasingly critical. In 2024, renewable sources generated over 50% of the UK’s electricity for the first time, underlining how central wind, solar and other renewable technologies now are to the country’s energy system. As reliance on renewables continues to grow, so too does the need for resilient, well-protected infrastructure that can operate reliably in all conditions.
Protecting transformer assets was critical, not just for the site itself, but for the wider energy system and the customers who rely on consistent, low-carbon power.
In this context, even relatively small points of failure, such as poorly sealed cable entry points, can have a disproportionate impact. Water ingress or environmental damage at a BESS site can lead to equipment failure, reduced capacity and unplanned outages, affecting grid stability at times of peak demand.
Reliable sealing of large cable entry points was essential to protect equipment from water ingress and environmental damage.
The challenge
The windfarm needed to remain operational throughout the works, continuing to store and distribute renewable energy. Only two transformers could be isolated at any one time, and all entry points were located at ground level with restricted access. Several openings also required modification before sealing could begin.
The project required a solution that could be delivered within a live renewable energy environment, without disrupting energy storage, generation or distribution.
The solution
CSD worked in close collaboration with the renewable energy company to plan and deliver the works with minimal disruption. A phased programme allowed transformers to be isolated, sealed and re-energised in pairs, ensuring the site remained live throughout.
Where required, stainless steel L-brackets were installed to create suitable openings. The NOFIRNO® Duct Seal System was then installed across all transformer entry points, providing a consistent and flexible solution despite variations in opening size and shape.
CSD’s experience supporting critical energy and utilities infrastructure meant the team understood the operational pressures facing renewable assets. The NOFIRNO® system was selected for its proven performance, long-term durability and ability to adapt to non-standard openings often found across large-scale energy projects.
The outcome
The project was completed successfully without interrupting energy storage or distribution.
By protecting transformer assets at the BESS site, the works help safeguard the reliable delivery of renewable electricity at a time when the UK grid is increasingly dependent on clean energy sources.
Results
- Improved protection of critical energy infrastructure
- Reduced risk of equipment failure and outages
- Greater resilience in the delivery of renewable energy to customers
