BSI - PAS 63100:2024 - Protection Against Fire of Battery Energy Storage Systems for use in dwellings - Specification
Published: September 2024. This Publically Available Specification (PAS) from the British Standards Institution (BSI) was sponsored by The Department for Energy Security and Net Zero. This is not a British Standard and the guidance was developed in response to an urgent demand for clarity as to good practice across the industry including product, service and process standards.
The full document came into effect on the 31st March 2024 and can be downloaded free here: BSI - PAS 63100:2024 - Protection Against Fire of Battery Energy Storage Systems for use in dwellings - Specification
The provisions within the document are intended both to reduce the risk of energy storage batteries being a source of fire ignition as well as limiting the impact of a fire ignited elsewhere within a domestic environment should it come into contact with energy storage batteries.
Who is PAS 63100 for and to whom does it apply?
The PAS is guidance for both by new consumers and competent designers and installers of low voltage residential battery energy storage systems to help ensure that the risks of energy storage systems are understood and that they are installed as safely as possible with regards to fire safety.
 |
PAS 63100:2024 is a generally well researched and comprehensive document incorporating valuable input from across the industry and citing many sources of additional research and information. Essential reading for anyone involved with the designing and or commissioning of a battery based energy storage system. The guidance applies to domestic dwellings with a floorspace up to 200m2, and does not apply to batteries up to 150Wh such as those found in fire alarms, intruder detection systems and pluggable UPS systems. NB: Owners of Existing Battery Storage Systems: This guidance has been a long time in coming and we know that there are plenty of battery energy storage systems installed in the UK (particularly in lofts) that would not meet the current guidance published (but not supported) by the BSI, if installed today. As with all changes to regulations, standards and guidance, this cannot be applied retrospectively to existing installations. It is also important to note that this document doesn't differentiate between the different types of batteries and battery chemistries that are on the market today, each type having a very different risk profile when it comes to fire safety. |
We do however encourage owners of existing systems, particularly if concerned about the fire safety of their installation to read through the guidance below. It might not be practicle or realistic to implement every recommendation but it does contain some useful ideas and we've added some of our own, as to how fire safety in relation to energy storage batteries could be improved, this could include the installation of a fire detection system, installing an air vent, moving batteries into a fireproof enclosure, moving batteries off a timber joist floor and mounting securely to a wall, installing fire doors or moving the batteries and or inverters to a more suitable location.
Where should energy storage batteries be installed?
The basic assumption throughout PAS 63100 is that the best location for energy storage batteries to be installed is outdoors, away from habitable rooms and fire escapes. Garages and outbuildings that are either detached or separated by a suitable main wall for the purposes of this document are classed as outdoors and are often suitable locations, when this isn't practicable and batteries are installed inside a dwelling, the following principles apply:
 |
Energy storage batteries should not be installed in the following locations:
|
Mechanical Impact: When energy storage batteries are installed on external walls, on driveways, inside garages or in any other location where they might come into contact with cars or other sources of mechanical impact, additional attention should be paid to the suitability and strength of enclosures and impact barriers.
External Walls: When energy storage batteries are installed within enclosures on an external wall the installation must not compromise the fire performance of the wall including service penetrations. Suitable fire stops and barriers should also be installed in wall cavities to prevent access to combustible materials.
Airing Cupboards & Storage Cupboards
On the basis that adequate fire detection, fire containment (which might include a fire door) and fresh air ventilation is available and the airing/storage cupboard doesn't open out into a room where people are intended to sleep, these could potentially be suitable locations to install energy storage batteries, particularly if the batteries were mounted in a fire resistant enclosure and able to be secured to the inside of an external wall. Particular attention will need to be made to ensure that in the event of a fire that escape routes would not be impeded.
Under-stairs Cupboards
As a battery fire under the stairs could impede a protected escape route, new battery energy storage systems shouldn't be installed under stairs. For those with existing systems installed under stairs, in the first instance our advice would be to see if batteries could be moved to a different location.
If moving the batteries isn't an option, the risk of mechanical damage could be reduced and fire performance improved by installing the batteries in a fire-resistant enclosure. A smoke/fire alarm installed near the batteries would improve the chances of alerting people to the fire, allowing time to address the fire and or get people out. Installing an air vent would allow problematic or overheated batteries to off-gas and or cool down and help avoid fumes entering the home.
Voids, Roof Spaces and Lofts
Although for different reasons we've never needed to install batteries in roof spaces and lofts, as we regularly test and repair these systems, we know that plenty of people have. Although it's fair to say that many installers care more about installing new systems then repairing or maintaning them, it's also fair to say that although we don't get to see many new ones, that the majority of the systems that we do see, that have been professionally installed into roof spaces and lofts have been designed sensibly with regards to fire mitigation and have been installed well.
It is also our opinion that when installed correctly and with the right precautions inline with the stated intentions of PAS 63100 that we are exploring here, if this new document didn't specifically try to prevent us from doing so, that a roof space or loft after an evaluation, employing an appropriate technology might otherwise prove to be the best and most logical location in terms of fire safety to locate energy storage batteries. PAS 63100 is a starting guidance document onto which we expect further standards and regulations to be built. We anticipate that before too long this guidance will develop and finesse further, incorporating feedback and input from other equipment manufacturers with safer battery technology, other industry players and the different real world scenarios we find with the different battery types and the unique locations in which we find them.
Although fire safety can likely be improved with many systems and we welcome this guidance, we appreciate that the guidance itself can, should and will hopefully be improved upon and that the introduction of PAS 63100 doesn't all of a sudden make battery storage systems installed in lofts that have been working perfectly fine until now, inherently unsafe. Clients with battery storage systems installed in roof spaces and lofts are welcome to contact us to discuss any concerns or to discuss how their systems in relation to the issues raised in PAS 63100 and fire safety might be improved.
How much battery Energy Storage can be installed serving a single dwelling?
PAS 63100 states that the total stored energy of all units in an individual dwelling house shall not exceed:
- 80kWh where energy storage batteries are installed in outbuildings, detached garages and attached garages with adequate fire separation
- 40kWh in all other cases
Where are warning labels and notices needed?
 |
When a battery energy storage system is installed, particularly if it's capable of backing up a property's power supply (either in full or in part), it's vitally important that in the event of a fire that the firefighters are aware of the presence of the Battery Energy Storage System (BESS). Warning labels and notices should be installed at the following locations:
|
When and where are fire alarms/detectors needed?
When batteries, inverters and other Power Conversion Equipment (PCE) are installed in lofts, store cupboards and other infrequently visited locations a fire/smoke detector/alarm should also be installed in that location. The detector/alarm should be integrated with the rest of the property's fire/smoke detection system.
Premises whose electrical installation incorporates a Battery Energy Storage System (BESS) should have an appropriate fire detection and fire alarm system of at least Grade D2, Category LD2.
A Category LD2 system incorporates smoke detector/alarms or multi-sensor fire detector/fire alarms covering any specified rooms or areas that present a high fire risk to occupants in addition to covering means of escape.
General electrical installation and prevention of fire and burns from DC arcs
Where battery assemblies are connected in parrallel strings, and are in one or more separate enclosures, common protection from overcurrent shall be provided. Batteries shall comprise non-combustible enclosures containing the overcurrent protection with the cells/monoblocs.
|
It shall not be possible to remove DC power connections without:
Fuses for DC circuits of batteries shall be:
The image to the left shows examples of a compliant and a non compliant system. |
System Controls & Mechanical Safety
 |
|
Solar PV Systems & Equipment, including Electrical & Roofing Systems
Grid-tie inverters, Hybrid Inverters, AC Coupled Inverters, Battery Storage Inverters, Off-Grid Inverters, Charge Controllers, Transfer Switches, Hot Water Controllers, Optimisers, Lithium Batteries, Lead Acid Batteries, Solar Panels, Mounting Systems, Test Equipment, Earthing Equipment, Electrical Distribution Equipment, Cable and Accessories
 |
Deliveries to anywhere in the UK are quick, tracked and accurate, technical support (by phone and on site if needed) and design/product advice is available before, during and after installation. The recording and collating of serial numbers, factory and other test results, manuals any other information required for equipment warranties, add ons and extensions is included. Trade, DIY and Retail Clients Welcome. |
Bespoke system design, equipment testing and integration support as well as on-site technical support and job/equipment specific training is available for off-grid, hybrid, larger and or more complex systems.
Mains/Grid Isolation and Surge Protection
 |
A whole house surge protector is installed to provide protection from transient overvoltages originating from the mains/grid. A whole house surge protector is installed directly inline and as close as possible to the incoming mains/grid supply meter, this allows for surge protection for all circuits and equipment including solar inverters, routers, stereos and other sensitive electrical equipment within the network. The addition of a 100Amp lockable isolator also allows for safe and convenient isolation of all electrical equipment within the network including consumer units, solar inverters, battery storage units and EV chargers from the mains/grid in one place. Surge protectors are in compliance with the recently updated 18th edition amendment 2 of BS7671. |
Solar PV Surge Protection (DC Surge Protection)
 |
DC surge protection devices (SPDs) are installed between the solar panels and the solar inverter to protect both the solar inverter and the downstream electrical equipment from transient overvoltages of an atmospheric origin impacting the electrical system via the DC side of the system / the solar panels. DC Surge protectors are in compliance with the recently updated 18th edition amendment 2 of BS7671. |
Articles: Further Information, Calculators & Solar Inverter Fault Codes
Lots of articles, calculators and technical information including links for further reading. Covering a range of topics related to the installation and maintenance of solar photovoltaic and electrical systems in the UK.
.jpg) |
Engineering Recommendation G98Grid Connections for Micro-Generators including Solar PV Systems and Elecricity Storage Systems in the UK. Under 16Amps Per Phase, grid synchronised. How to provide power to a house using a portable generatorIn this article we show you how to power your home using a portable diesel, petrol or LPG generator. We look at changeover switches, the importance of earthing, generator loadings, how to isolate non essential loads. We ask where to locate the generator when it's in operation, how best to safely isolate the grid/mains power supply and switch to a generator supply. Ground Faults, Isolation (ISO) Faults, RISO low Faults and Insulation Resistance Faults with Solar PV SystemsAfter a number of years exposed to wind, rain, snow, ice and sometimes animals; solar panel systems can start to develop faults. The most common faults we find related to exposure are ground faults, isolation (ISO) faults, RISO low faults and insulation resistance faults. In this article we take a look at what these faults are, the possible causes and what steps are taken to identify and resolve them. |
Areas Served:
We are located in Wanborough, very close to Swindon in Wiltshire, Southern England, UK. From here we service clients within a 90 minute driving radius including the towns, cities and regions below:
Swindon: Abingdon, Aldbourne, Amesbury, Andover, Banbury, Basingstoke, Bath, Berkshire, Bicester, Blunsdon, Box, Bracknell, Bradford on Avon, Bridgwater, Bristol, Buckingham, Burford, Burnham on Sea, Calne, Camberley, Cardiff, Carterton, Cheltenham, Chippenham, Chipping Norton, Chipping Sodbury, Cirencester, Corsham, Cricklade, Devizes, Didcot, Evesham, Eynsham, Faringdon, Frome, Fleet, Glastonbury, Gloucester, Gloucestershire, Hampshire, Henley-on-Thames, Highclere, Highworth, Hook, Hungerford, Keynsham, Kingsclere, Lambourn, Lechlade, Ledbury, Ludgershall, Lyneham, Maidenhead, Malmesbury, Marlborough, Marshfield, Melksham, Minety, Newbury, Newport, Oxford, Oxfordshire, Pewsey, Purton, Ramsbury, Reading, Ross on Wye, Royal Wootton Bassett, Salisbury, Shaftesbury, Shalbourne, Slough, Southampton, Stow, Stratford upon Avon, Stroud, Swindon, Tewkesbury, Thatcham, Tidworth, Trowbridge, Wanborough, Wantage, Warminster, Weston Super Mare, Wiltshire, Winchester, Windsor, Witney, Wokingham, Worcester, Wroughton and Yate.
Privacy: None of your data will be collected and nothing will be installed on your device.
We do not use cookies, trackers, fingerprinting or embedded scripts on this website.
©2007-2024 - In Balance Energy