Power generation and energy storage fires can be very costly, potentially resulting in a total write-off of the facility. Fires happen quickly and may spread fast, destroying critical company assets. Passive fire protection may lower risk but ignition sources and fuel supplies remain.
Remote and unoccupied spaces with indoor and outdoor switchgear, transformer equipment, turbine rooms, generator rooms, electrical cabinets, converters/ inverters and lithium-ion batteries are real fire hazards where active fire protection is needed.
Battery Energy Storage Systems
Renewable Energy technologies such as solar and wind are at the mercy of the prevailing weather conditions, only able to operate intermittently, creating a problem of balancing supply and demand.
Solutions that have been developed in recent years are Battery Energy Storage Systems (BESS), having the ability to capture and store excess generated electricity for delayed discharging. A BESS can also be standalone, connected directly to the grid.
BESS as an industry is still very much in its infancy but 2018 saw the start of rapid deployment throughout the UK and all forecasts point to exponential growth on a global scale. Nobel has been at the vanguard of this emerging sector, providing:
- Stat-X fire protection to a 41MW grid-scale in-building BESS in the West Midlands on behalf of leading BESS integrator, GE.
- Stat-X fire protection to containerised BESS units for European energy companies in Germany and the Netherlands.
- Stat-X fire protection to a containerised BESS solution in Greece on behalf of a major US BESS integrator.
- Consulting and maintenance work on behalf of BYD, the major Chinese Lithium-ion battery manufacturer and BESS solutions provider operating in the UK.
By far the most dominant battery type installed in an energy storage system is Lithium-ion, which brings with it particular fire risks. Think spontaneously exploding mobile phones and laptops on planes that have hit the headlines in recent years.
- Lithium-ion batteries are especially at risk of ‘thermal runaway’, a self-perpetuating chain reaction in which excessive heat keeps creating more heat, potentially spreading from one battery cell to the next and causing widespread damage.
- During thermal runaway, oxygen is believed to be selfgenerated during cathode consumption, plus there are multiple internal sources of fuel in a lithium-ion battery (metals, plastic, electrical, flammable gases and liquids).
- Lithium-ion battery fires are ‘deep-seated’, as the materials involved in the ignition and propagation of the fire are tightly integrated into a cell, making fire-fighting a challenge.
- Lithium-ion battery fires are at risk of ‘re-flash’, hours or even days later having seemingly been put out.
- Fire fighters and other emergency services have little or no experience of this type of hazard, which presents risk of fire, electricity and fume toxicity, with the use of water potentially perpetuating the battery fire by additional cell shorting. It goes without saying that water damage results in the total loss of asset, which at scale have a capital cost of tens of millions of Pounds with attendant insurance issues.
- Lithium-ion batteries must be handled with care, in transport and during installation, as they are very sensitive to mechanical damage (such as crush or puncture) and electrical surges, which can result in short circuits leading to internal battery heating, battery explosions and fires.
- Battery management control systems can be faulty or fail, leading to an inability to monitor the operating environment, such as temperature or cell voltage, with the potential for overcharging.
Regulations and Fire Testing
As recently as 2014, private safety standards firm Underwriter’s Laboratory (UL) published the first safety standards relating to energy storage; UL 9540.
UL is the underlying standard on which many international and national organisations base their regulations and fire codes. In addition, UL 9540A was drawn up in November 2017 to specifically address ‘Thermal Runaway Fire Propagation in Battery Energy Storage Systems’. Three further iterations of the standard have been published in the intervening period, demonstrating a rapidly evolving regulatory environment. Furthermore, more recently the National Fire Protection Association of the US published its own standard for the ‘Installation of Stationary Energy Storage Systems’, NFPA 855, which specifically references UL 9540A. The International Fire Code (IFC) will also publish its most robust ESS safety requirements in the upcoming 2021 edition.
However, in parallel with these regulations and anticipated future developments, Stat-X has undergone private and commercial testing with lithium-ion battery OEMs and BESS integrators; so far with success and subsequent deployment in the field. Nobel believes Stat-X is the optimal ‘first responder’ suppression system to address the threat of a BESS fire. To provide cooling and aid extinguishment in the event of a lithium-ion battery fire and attendant thermal runaway, Nobel recommends the installation of an external fire brigade pumping-in breech linked to deluge mist nozzles within the BESS for water back-up as required.
BESS assets can be found at all scales, from in-cabinet to container to in-building.
Although an energy asset, Battery Energy Storage Systems are not the preserve of traditional power and utility companies accustomed to dealing with the specialised operational demands. BESS developers and end use customers are as likely to be financial investors, property developers, industrial parks, factories or councils with limited understanding of the inherent risks and dangers.
As such, it is critical to work with BESS owners, contractors and integrators at the initial design stage to fully understand all aspects of fire risk and associated hazards specific to the site. Stat-X fire suppression generators are the first and principal line of defence against a Lithium-ion BESS fire, however, there is a suite of additional solutions to consider in monitoring, protecting and managing fire risk:
- Control Panel technology
- Detection; fire and gas
- Ventilation control
- Battery Separation and Containment
- Interface with customer house alarm and systems
- Emergency procedures, including warning signs, sounders and manual release facility
- Water back-up
- Maintenance, servicing and ongoing customer support
- Installation protocol – all BESS fire protection installations carried out by dedicated team of experienced Nobel engineers
The Benefits of Stat-X
Stat-X is an innovative, self-contained, environmentally friendly suppression system, proven to be extremely effective where there is a need to protect critical areas and high value enclosures.
- Stat-X is a condensed aerosol fire suppression system; it is compact and requires no pipework or nozzles with the generators being placed directly on or in the risk being protected.
- Stat-X systems are bracket mounted within the BESS on the ceiling or walls, taking no valuable floor space.
- There is no cylinder weighing or hydro-static testing required.
- The potassium-based suppressant works in a similar way to gas but, unlike gas, the aerosol remains in suspension for up to an hour providing extended postfire security against re-ignition.
- Gas requires an airtight enclosure, which can only be ensured by passing a Room Integrity Test. Stat-X has no such restrictions – calculations allow for un-closable openings.
- Stat-X provides fast and secure knockdown of lithium-ion battery fires, avoiding the associated damage to equipment and site of sprinklers or other water deluge systems. In the event of thermal runaway, the option of deploying a water back-up system is provided via a fire bridge pumping-in breech.
- 10-year service life.
Contact us for more information about condensed aerosol systems.