Incident evidence for Y Bryn Wind Farm

1. Key findings for this site

• The register holds 5 incidents at grid-scale battery sites in the UK, 1 of them major. Home, farm and business batteries are counted apart (9).
• The nearest is EIR-0249, Smoke and fire incident at Battery Box, Pinhoe Road, Exeter, about 96 km from the site.
• No recorded incident lies within 50 km of the site.
• 2 battery energy storage sites within 40 km have had an application refused, withdrawn or taken to appeal. Final outcomes: 1 refused, 1 granted. The nearest is Pound Farm Lane - Battery Storage (granted after resubmission), 28 km away. 3 schemes under 1 MW are listed apart.

Counts are of incidents in the register, which is built from published reporting. They are not rates and not a complete census.

2. Grid-scale battery incidents in the UK (5)

Nearest to the site first. Distance is a straight line from the site point to the place the entry is mapped to (a town or a site).

Each incident against the NFCC guidance

What the reporting says, set against the passages of the National Fire Chiefs Council guidance that fire service consultees cite. The guidance is advice to fire services, not law, and most of these sites were built before its current edition. The notes do not say a site broke it.

4. Every recorded incident within 50 km

Measured on a map from the planning record for Y Bryn Wind Farm. Every size of site is included here, so a home battery fire nearby is shown, marked as such. Entries are found by their map point only, never by matching words in the text. 3 UK entries have no map point yet and cannot be measured.

None within 50 km.

5. Grid-scale incidents at sites of a similar size

No capacity was given, so this section is empty.

6. Lessons for a grid-scale site

The lessons written into the register's entries: every UK grid-scale incident first, then major grid-scale incidents elsewhere. No home battery lessons. Each is the register's reading of the published reporting, not a finding by an investigator.

1. BESS containers need verified automatic fire suppression that activates on detection, as the system here failed to actuate and allowed thermal runaway to continue. EIR-0638
2. A site monitored remotely must alert the local fire service as soon as its fire alarm actuates. Here the site was managed remotely by Orsted from Denmark, and that remote management did not alert the fire service when the alarm actuated. Orsted first contacted Fire Control at about 01:30, after the first crew had arrived at 00:57. EIR-0638
3. Site risk information must include BESS layout, chemistry and voltage so crews can plan defensive tactics before arrival, given the explosion and debris. EIR-0638
4. Grid connection cabinets at battery sites need routine thermal and electrical checks as well as the battery modules. EIR-0249
5. Operators should agree isolation steps with the network operator in advance so fire crews can act quickly. EIR-0249
6. Joint reviews with the network operator help separate grid faults from battery faults. EIR-0249
7. A short circuit in NMC lithium-ion cells can start a fire, so operators should fit detection systems able to isolate strings before thermal runaway spreads. EIR-0584
8. Battery management systems must be proven to detect abnormal cell voltage or temperature early, as the trigger for this short circuit was not stated. EIR-0584
9. Owners should publish cause findings after a BESS fire, as the owner did here, so other operators can check the same failure mode in their own fleets. EIR-0584
10. Lithium-ion battery container fires can spread between enclosures, so operators should verify separation distances and compartment barriers during design reviews. EIR-0058
11. Smoke from burning battery materials requires advance shelter advice for nearby residents at rural sites. EIR-0058
12. Unmanned hybrid sites need remote monitoring that identifies involved enclosures before crews arrive. EIR-0058
13. Containerised battery units must keep designed spacing during construction, as separation limited spread after a cell fault led to ignition. EIR-0109
14. Fire response plans and contacts must be agreed with local crews from the start of construction, as the site was evacuated and handed back after the fire. EIR-0109
15. Unenergised battery units remain a fire risk in the construction phase, so risk assessments must cover evacuation triggers and site handover. EIR-0109
16. Grid-scale storage in a single large building rather than separate containers requires review of total fire load and internal barriers to limit propagation between racks. EIR-0010
17. A pattern of repeated minor thermal events at a site should trigger a documented root cause review before adding further capacity. EIR-0010
18. Plan in advance for reignition during the days and weeks after the initial event, including continued monitoring and safe removal of damaged units. EIR-0010
19. Grid scale lithium ion battery fires can produce weeks of flare ups, so operators must plan for extended site security and monitoring after the initial event. EIR-0013
20. Cleanup of fire damaged lithium ion cells requires environmental monitoring and specialist disposal, so contracts and protocols should be ready before any incident. EIR-0013
21. Regulatory settlements after battery fires can impose months of reporting duties without fines, so emergency plans must allocate staff for ongoing compliance. EIR-0013
22. Co-located solar and battery sites need isolation plans that cover both electrical faults and thermal events together. EIR-0006
23. Evacuation plans for sites near schools and businesses must account for toxic smoke from lithium-ion events. EIR-0006
24. Water supply planning for co-located sites must cover sustained high volumes over multiple days. EIR-0006
25. NMC lithium-ion cells in a utility-scale BESS can produce flare-ups for days, so operators must plan for prolonged monitoring and exclusion zones after the first signs of thermal runaway. EIR-0001
26. A prior thermal event at the same BESS site raises the chance of repeat failure, so response plans must record and brief staff on that history. EIR-0001
27. NMC cells and high cell density increase propagation risk, so operators should verify that enclosure spacing and containment match the chosen chemistry in the safety case. EIR-0001
28. NOVEC 1230 fire-suppression gas combined with firefighting water at a BESS site can form PFPrA at 10,000 parts per billion, so operators should test suppression chemistry for persistent environmental byproducts before use. EIR-0643
29. Only 0.04 per cent of batteries burned at this modular containerised site, so insurers should verify that design limits fire spread compared with enclosed buildings. EIR-0643
30. Four water wells 2,500 feet from the plant were taken out of service after PFPrA detection, so operators must agree groundwater testing protocols with regulators in advance. EIR-0643
31. A lithium-ion battery at 95% state of charge releases large stored energy during fire, so operators should supply state of charge data to responders before any incident. EIR-0130
32. Opening a battery container after inert gas suppression can trigger thermal event and explosion, so procedures must set safe stand-off distances before doors are opened. EIR-0130
33. Automatic fire suppression systems may fail to stop thermal runaway in lithium-ion containers once it starts, so operators should plan for remote isolation and long-duration response. EIR-0135
34. Critical data servers inside battery containers risk total data loss in a fire, so they should be placed in a separate enclosure. EIR-0135
35. Battery fires can last several days, so emergency plans must include sustained cooling and exclusion zones rather than short interventions. EIR-0135
36. A lithium-ion BESS fire may require robotic entry to assess gases before any person goes inside, so operators should arrange remote entry tools with the fire service in advance. EIR-0025
37. Sprinkler systems in battery storage buildings are designed for containment over many days, so plans must cover prolonged water supply, drainage and run-off control. EIR-0025
38. A prior explosion at a nearby battery site led to a defensive response here, so local fire services should embed earlier incident findings in pre-plans for similar facilities. EIR-0025
39. Liquid cooling system leaks in Megapack units can cause arcing in power electronics, so pressure test and inspect every circuit after installation before energisation. EIR-0012
40. SCADA mapping latency of around 24 hours during commissioning leaves new units unmonitored, so do not energise until full telemetry and alarms are verified active. EIR-0012

7. The NFCC guidance points consultees cite

Quoted word for word from NFCC, Grid scale energy storage system planning: Guidance for fire and rescue services (approved for publication in December 2025, replacing the first edition), checked on 8 October 2026. Many consultee responses still quote the first edition (Version 1.0, November 2022), so its figures are given too, marked as such.

Scope

"This guidance relates to battery energy storage systems (BESS) which are deployed in open air environments, with an energy capacity of one megawatt hour (MWh) or greater using lithium variant batteries."

"Domestic BESS are outside the scope of this guidance."

"As such, the fire and rescue service are not a statutory consultee in planning applications for BESS sites."

Spacing between units, and to buildings

"The emergency response plan should assume that the fire will not spread beyond the BESS container of origin."

"An initial minimum distance of 30m is proposed between BESS cabinets (or associated infrastructure such as transformers and switchgear) and occupied buildings, before considering any mitigation such as blast walls."

"A standard minimum spacing between units of 6 metres is suggested unless suitable design features can be introduced to reduce that spacing."

Water for firefighting

"Therefore, an additional on-site water supply must be accessible to fire and rescue services in the event of an emergency."

"Fire hydrants provided should achieve a flow rate of no less than 25L/sec at any hydrant on the site."

"Where a flow of 25L/sec cannot be achieved, it would be prudent to provide an equivalent static supply of water on site that will provide for the same flow rate for a duration of 120 minutes. This equates to approximately 180,000L of water."

"As a minimum, it is recommended that hydrant supplies for boundary cooling purposes should be located close to BESS containers (but considering safe access in the event of a fire) and should be capable of delivering no less than 1,900 litres per minute for at least 2 hours."

Detection, alerting and isolation

"An effective and appropriate method of early fault detection within the batteries should be in place, making it possible to immediately disconnect the affected battery/batteries remotely."

"How will the BESS and associated equipment be monitored, and what is the process for alerting the fire and rescue service?"

"How the fire and rescue service will be alerted"

"Emergency shutoff or isolator locations"

Suppression and explosion control

"The suppression system, regardless of type, will have little effect on a thermal event within the battery cell."

"BESS containers should be fitted with explosion protection or deflagration venting appropriate to the hazard and battery technology deployed."

Access, neighbours and how long an incident lasts

"It is therefore preferable to have an alternative access point, taking account of the likely wind direction."

"The developer should produce a plan that identifies all sensitive receptors within a 1km radius of the site."

"The assessment should recognise that any incident may last several hours."

10. Kept apart: other battery entries in the UK (9)

Home, farm and business batteries, concerns raised where nothing failed, and events at battery sites that were not battery failures. NFCC's grid-scale guidance does not cover home batteries ("Domestic BESS are outside the scope of this guidance."), so they are listed here and not in the tables above.

12. How this pack was made and checked

1. The register is built from published reporting: news, fire service statements, regulators and court records. Each entry lists its sources on its own page. Entries marked provisional rest on thinner sourcing and are rechecked.
2. Grid-scale or not: an entry is grid-scale unless its reporting describes a home, farm or business battery, or an event that was not a battery failure. The rule is the same for every pack.
3. Distances are measured from the site point (the planning record for Y Bryn Wind Farm) to each entry's map point, which is a town or a site, never an address.
4. Planning decisions come from the government's Renewable Energy Planning Database (Open Government Licence v3.0), with corrections where a council's own record shows a later decision.
5. Desk review. The EIR editorial desk checks each bought pack within 2 working days (Monday to Friday) of the order:
   1. The site point and planning authority match the planning record, or the details the buyer gave.
   2. Each UK incident is a separate event, not one fire written twice, and sits in the right table: grid-scale sites in the main table, home, farm and business batteries apart.
   3. Each UK grid-scale incident has a note, and every quoted passage matches the NFCC text at the link given.
   4. The three nearest planning decisions match the council's own planning record.
   5. The distances to the nearest incidents look right on a map.
   6. Nothing in the pack comes from a confidential submission or names a private person.
6. If anything needs changing, the desk makes a new version and emails the link. Every version is fixed and dated, and earlier versions stay available at the same link. The method is at energyincidentregister.com/pack-method.
7. Information only. It is not engineering, fire safety or legal advice. See the disclaimer.

How to cite: Energy Incident Register, planning evidence pack EIR-PACK-D-Y-BRYN-WIND-FARM-GB-16392, data as of 29 October 2026, energyincidentregister.com.

A correction to any entry is free for anyone: corrections. Questions about this pack: editor@energyincidentregister.com.