Part of the BRE Trust
A Fire Safety OverviewBRE Trust/BPVA WorkshopPhotovoltaics and Fire: Separating fact from fiction 12th July 2011, BRE, Watford
Martin ShippTechnical Development Director, Fire Safety, BRE Global
Electricity can cause fires
Fire Statistics; electrical firesAll dwelling fires: proportion of electrical and non-electrical fires
electrical fires
chip/fat pan fires
other fires
All dwelling fires: proportion of electrical and non-electrical fires .
electrical fires
chip/fat pan fires
other fires
Fire Statistics; electrical firesElectrical fires in dwellings: proportion of fires due to different causes
faulty fuel supply
faulty lead
faulty appliance
misuse
play or carelessness
heat source too close
other cause
Electrical fires in dwellings: proportion of fires due to different causes
faulty fuel supply
faulty lead
faulty appliance
misuse
play or carelessness
heat source too close
other cause
Fire Statistics; electrical firesElectrical fires in dwellings, proportion of fires from different items first ignited
Electric cookers
Microwave cooker
Other electric cooking appliance
Electric space heater
Electric central heating
Electric water heating
Electric welding & cutting appliances
Electric blowlamp
Washing machine
Dishwasher
Refrigerator
Tumble driers
Spin driers
Lighting
Blanket or bedwarmer
Television
Iron
Audio visual
Computer or VDU
Kettle,Urn,etc
Other electrical
Electrical fires in dwellings, proportion of fires from different items first ignited
Electric cookers
Microwave cooker
Other electric cooking appliance
Electric space heater
Electric central heating
Electric water heating
Electric welding & cutting appliances
Electric blowlamp
Washing machine
Dishwasher
Refrigerator
Tumble driers
Spin driers
Lighting
Blanket or bedwarmer
Television
Iron
Audio visual
Computer or VDU
Kettle,Urn,etc
Other electrical
Many new sustainable/environmentally friendly technologies have fire safety implications
• Modular construction
Many new sustainable/environmentally friendly technologies have fire safety implications
• Modular construction
• Timber frame
Many new sustainable/environmentally friendly technologies have fire safety implications
• Modular construction
• Timber frame
• Structural Insulated Panel Systems
Many new sustainable/environmentally friendly technologies have fire safety implications
• Modular construction
• Timber frame
• Structural Insulated Panel Systems
• Engineered joists
• Cladding systems
• Wind generators
Many new sustainable/environmentally friendly technologies have fire safety implications
• Do all new technologies introduce new fire risks?
The issues for PVs
– PV systems can cause fires: fact or fiction?
– PV systems exacerbate fire hazards: fact or fiction?
– PV systems present new electrical risks to firefighters: fact or fiction?
With the permission of Bodo Wolters
PV systems can cause fires: fact or fiction?
– DC not AC
– Installation requires new skills
– Quality of installation critical
– Risk of “cowboy” installers?
– Maintenance important
î
PV systems exacerbate fire hazards: fact or fiction?
– Falling glass
î
PV systems exacerbate fire hazards: fact or fiction?
– Falling glass
– Roof loading (added risk of structural collapse due to weight of panels)
î
PV systems exacerbate fire hazards: fact or fiction?
– Falling glass
– Roof loading (added risk of structural collapse due to weight of panels)
– Poorly installed panels may obstruct/restrict use of roof windows as means of escape
– windows as means of escape
– Fire spread to other properties from panel materials
PV systems present new electrical risks to firefighters: fact or fiction?– Potentially very high DC
voltages (1000 volts?) - more dangerous than normal electrical installations
– Always live – can only shut off utilities, not supply to the inverter
– Shock risk if cables or conduits are cut
– Shock risk from batteries– Shock risk down water jet– (e.g. Switzerland 2002) î
PV systems present new electrical risks to firefighters: fact or fiction?
– Fire fighters may not recognise PV system – lots of different types
– Fire fighters not used to dealing with DC
– Don’t know what to expect
PV systems present new electrical risks to firefighters: fact or fiction?
– Fire fighters may not recognise PV system – lots of different types
– Fire fighters not used to dealing with DC
– Don’t know what to expect– AC detectors will not detect
DC?– Will there be an emergency
switch?– Where?– What if not ?
PV systems present new electrical risks to firefighters: fact or fiction?– Fire fighters may not recognise
PV system – lots of different types
– Fire fighters not used to dealing with DC
– Don’t know what to expect– AC detectors will not detect
DC?– Will there be an emergency
switch?– Where?– What if not?– Confusion with solar thermal?
Heavy metals released: fact or fiction?
– Cadmium Telluride? CdTe
– Only a problem if exposed to very high temperatures? 1100 deg C – seldom reached in uncontained fires.
– Gets encapsulated by glass?
Stories from US
– Firefighters cut through panels to vent fire -electrocution
– Panels prevent venting
– Panels may be slippery – hazard for fire fighters on the roof
– May limit access to and use of roof
– Looking at use of portable covers
Stories from Germany
– 1000 volts DC down hose?
– German firefighters refused to fight fires involving PVs
PV systems can cause fires?
– Installation guides recognise fire risks
PV systems can cause fires?
– Installation guides recognise fire risks
PV systems can cause fires?
– Installation guides recognise fire risks
– Cut off switches on the market
PV systems present new risks to firefighters?
– Other countries have produced guidance– US– Germany
PV systems present new risks to firefighters?
– Other countries have produced guidance
– Not aware of any problems/issues in UK (yet)
– Problem for fire risk assessors – how to assess risk?– risk assessors need
guidance– UK needs guidance to reflect
UK firefighting practice?
Fire and Rescue Service Operational GuidanceGRA 3.1 Fighting fires in buildings
– ELECTRICAL SYSTEMS ON EXTERNAL BUILDING FASCIAS
– Electrical systems may be found in external positions on buildings.
– These may include photo-voltaic panels and shop signs etc which present an electrical shock hazard, or shock track (electric) bird abatement systems, which although only being low voltage, may be hazardous if a firefighter were to touch it whilst at the head of a ladder.
Conclusions
– We need to ensure that all innovations in designs, products and materials that are supporting more sustainable and environmentally friendly buildings do not introduce unexpected fire risks.
– There may be some new fire risks associated with photovoltaics.
– Some of the concerns may be unfounded; others may need a response.
– We need to all work together to ensure that the fire issues are dealt with logically and professionally and not subject to simple commercial pressures.
– We need to all work together to develop practical solutions, and practical guidance.
Thank you
Martin Shipp, Technical Development Director, Fire SafetyBRE GlobalT: +44 (0) 1923 664960E: [email protected]: +44 (0) 1923 664910W: www.bre.co.uk/fireBRE, Garston, Watford WD25 9XX, UK