BESS Health and Safety
Health and Safety Guidance for Grid Scale Electrical
Energy Storage Systems
March 2024
Prepared for: Department for Energy Security and Net Zero
Grid scale applications
consist of multiple containers, connected via multiple inverters, transformers and switchgear under a single
point of connection to the electrical grid.
Prior to completing any work or activity, the stakeholder(s) should determine and assess the risks and
opportunities that are relevant to the intended outcomes of the management of H&S. The stakeholder(s)
should maintain documented information on risks and opportunities as well as the processes and actions
needed to determine and address its risks and opportunities to the extent necessary to have confidence
they are conducted as planned.
- Definition of the project,
- Identification of hazards,
- Estimation of risk,
- Evaluation of risk.
If the risk is deemed tolerable after these 4 steps, then it can be validated and documented. However, if it is
deemed an intolerable risk then the stakeholder should proceed to risk reduction, and then the re-
estimated and re-evaluation of the risk until it is deemed tolerable. Evidence and documentation of
completion of the sequence should be kept, and eventually validated to complete the risk assessment.
Risk management should be conducted through three main approaches
- Inherently safe design,
- Guards and protective devices and,
- Information for end users.
Equipment certification – having battery components tested under standards such as IEC 62619 and UL9540A3 is a key step in ensuring the robustness of battery installations. However, project integrators should not fully rely on test compliance, and ensure that their own specific system configuration matches standard test conditions.
Potential issues may include:
– Insufficient segregation or partitioning between battery modules, where adjacent modules may drive an increase in temperature increase.
– Ineffective management of off gases between racks within a container.
– Insufficient separation between containers
Designing for location weather – consideration should be given to how weather at the selected battery site may impact operating capabilities or asset degradation. Obvious examples include ambient temperature and how this might change over time (including the impacts of climate change and the possibility of extreme heatwaves). This could impact asset operation and cooling requirements.
Other considerations include locations near the coast, where coastal ‘salt air’ can accelerate corrosion.
An emergency response plan (ERP) should be produced detailing key actions and arrangements for foreseeable emergencies, including:
Response to fire incidents, including the firefighting strategy for large scale fires.
Management of potential chemical release (e.g. assessment of smoke plume impacts during fires, water and drainage management, including for contaminated run-off).
Response to severe environmental hazards such as flooding and operating in high winds (including responding to emergencies in these conditions).
Access/egress routes for staff, emergency responders and vehicles during emergencies including routes in and out of site, access to key equipment, out-of-hours response, site visibility particularly in dark conditions, sufficient turning circles secondary routes available if primary routes are blocked.
Emergency Response Planning
The emergency planning work undertaken at the Design & Planning stage should be subject to regular
review to ensure it remains fit for purpose throughout the lifetime of the BESS site. This should include:
Regular staff training, including evacuation drills, new starter briefings and refresher courses;
Testing and recertification of safety equipment, such as alarms and fire suppression systems;
Periodic review of emergency response plans, especially if site equipment or layout is modified or if the
site’s immediate neighbours or local access routes change;
Regular engagement with local Fire and Rescue Service to ensure they remain aware of current hazards
at the site – approaches to tackling these hazards may change over time.
Staff training – it is important that health and safety principles are embedded in training plans and that
training is delivered to all relevant staff, including contractors and temporary workers. This should cover
general risks and processes for working on site, specific risks to the tasks they will be undertaking and
points of contact for reporting or queries. Keeping accurate records of staff training is also important, as
it allows the organisation to plan for refresher courses as needed and demonstrate to external parties
that required training has been delivered.
Decommissioning and Repowering
The decommissioning of a BESS site presents similar health and safety risks to its commissioning, due to
changes in the site’s operation and potential removal of safeguards. Considerations at this stage include:
Disconnection from grid – the relevant TO/DNO should be consulted where work to remove grid
connection equipment is planned, to avoid disruption to the wider network.
Life extension/Repowering – it may be desirable to extend the working life of the site through
refurbishment or replacement of some equipment, such as degraded battery cells. Developers should
consider the rated lifetimes and condition of their equipment (e.g. the electrical distribution and
protection equipment that may be reused) and seek expert advice on potential safety risks from the
integrating new battery options.
New risks may also be introduced where storage equipment is repurposed, relocated or used in second life
applications.
Many of the principles described in earlier sections would apply for risk assessing these
applications.