Battery Energy Storage System concerns

The safety issue reported relates to a Battery Energy Storage System (BESS) which was built and commissioned in 2018.

Due to the drive to decrease reliance on fossil fuels and limit carbon emissions, renewable energy sources are increasingly being used. This increase in renewable energy comes with several challenges, one of which is that often renewable energy is produced when the grid doesn’t require the energy. This means the potential energy being created is either lost or stored for use when the grid requires it. For the latter case, there was a National Grid policy on Enhanced Frequency Response (ERF) which evolved into the Dynamic Containment system. This need for storage means an increase in BESSs to store energy when the demand in the grid increases.

The reporter is of the opinion that the application of Approved Document B (ADB) to meet the functional requirements of Building Regulations is not always sufficient for certain types of buildings, considering that BESSs should be considered as 'complex' situations. They think the technology in relation to BESSs is changing and evolving at a fast pace, and can potentially outpace current fire safety guidance or legislation.

To cater for these cases, the reporter considers it helpful to share some of the lessons learned from the project, so that practitioners can be aware of them and address the issues accordingly should they be encountered. The reporter raised three issues regarding their experience with the installation.

Firstly, a fire hydrant has not been provided within 90m of the site, and this was never picked up on in the consultation with the Fire and Rescue Service (FRS). In this case, that means that the nearest fire hydrant is some 1.7km from the site.

Furthermore, there is no Emergency Water Supply (EWS) at the site. It has been suggested that attenuation ponds can be used as an EWS but, in the reporter’s opinion, they cannot. This is for the following reasons: the attenuation ponds are seasonal and often there is no water within them, making them an unreliable solution; the attenuation ponds are also not deep enough for a fire appliance to obtain a lift; finally, there is no penstock which means it is not possible to contain water within the pond to provide an adequate depth.

This is of concern to the reporter, because should a fire situation occur at the BESS it is likely the delay in obtaining an adequate water supply could result in the fire spreading to include other electrical infrastructure. This is because it is accepted in the reporter’s circles that water is the best firefighting medium for the containment of a BESS fire. Large volumes of water could be required should an incident occur, though it should be clarified that this is not to extinguish the fire but to prevent it from spreading to adjacent installations or buildings.

The other issue raised by the reporter is that signage is often poorly displayed at the BESS. This means a first responder attending an incident may not be able to identify the message of the sign. In this case, the ‘Danger of Death’ signage displayed at the access points is not on a yellow background, only the inner portion of the triangle is yellow. Additionally, the signs have been placed on a brush steel effect background. Operators of BESSs, and FRSs, need to be made aware of the Electricity, Safety, Quality and Continuity Regulations 2002 in which Schedule 1 - Design, Colours and Proportions of the Safety Sign states:

'The triangle, symbol and text shall be shown in black on a yellow background.'

These sites are often remotely monitored – in the reporter's case the site is remotely monitored in another European country. Initially, however, the Automatic Fire Detection would only raise the alarm abroad and the monitoring company was able to summon the local FRS. This has now been resolved by the Automatic Fire Detection system being linked to an Alarm Receiving Centre in the UK. The Alarm Receiving Centre will contact the Centre in the other European country should a signal be transmitted to confirm a fire or false alarm.

The reporter made several suggestions that could potentially resolve many of the issues recognised in this report:

• To avoid similar issues from occurring in other BESS installations, it is crucial that the FRS and proposers of BESS to engage early in their design process. For this engagement to be meaningful, the FRS should acknowledge the BESS should initially be seen as a 'complex' situation (hence the application of only ADB rules for such premises not being acceptable to the reporter)
• Designers of BESSs within the UK should consider the usefulness and appropriateness of any rules found in NFPA 855 – Standard for the Installation of Stationary Energy Storage Systems. In the reporter’s experience, some suppliers, developers and designers have recognised the benefits of applying concepts of NFPA 855 to certain aspects of their design
• Operators of BESSs need to produce Emergency Response Plans (ERPs) for First Responders (firefighters). The ERPs need to be developed with the design specification of the BESS, but also in collaboration with the FRS that has responsibility for the BESS
• FRSs in England should provide guidance on the design specifications for EWS within their jurisdiction. This could be similar to the fire appliance access table e.g., the specifications for an above ground EWS to include connections for the FRS to discharge and resupply, a low-level alarm, or trace heating to prevent freezing
• More guidance is needed on the design specification for a BESS within England, considering that a document like NFPA 855 would be a beneficial tool for designers and reviewers