a. haring pv & fire safety--experinece in germany
TRANSCRIPT
SMA Solar Technology AG
PV and Fire Safety – Experience in Germany
Source :Homepage KBI Kötzting
Dipl. Ing. Adrian Häring, SMA Solar Technology AG 12.07.2011
SMA Solar Technology AG
1 Situation
2
3 Firefighting operations with and without PV installations
4
5
Firefighting procedures during nighttime
Scenarios
Conclusion and outlook
Agenda
2
SMA Solar Technology AG
1 Situation
2
3 Firefighting operations with and without PV installations
4
5
Firefighting procedures during nighttime
Scenarios
Conclusion and outlook
Agenda
3
SMA Solar Technology AG
• PV cells and modules operate as long as they are illuminated by a light source
• In case of fire or structure collapse, faults in PV systems are possible
• Correct and safe installations according to the technical standards can get
dangerous
The following questions regarding risk to firefighters needed to be answered:
• Is there danger for firefighters when buildings have PV systems?
• Is it possible to get an electric shock from the generator during nighttime,
caused by artificial illumination?
Situation: Risk of electric shocks during firefighting operations
4
SMA Solar Technology AG
1
Scenarios2
3 Firefighting operations with and without PV installations
4
5
Firefighting procedures during nighttime
Situation
Conclusion and outlook
Agenda
5
SMA Solar Technology AG
• Risk of an electric shock can be managed
• Parts of the PV plant readily identifiable
Firefighters can keep a minimum distance from the
plant,
e.g. in accordance with DIN VDE 0132 (Germany)
1m - 5m, depending on nozzle of fire hose
1m from (possibly) live parts
identical procedure to buildings
without PV systems
Source: Homepage KBI Kötzting
Scenarios: Firefighting outside a building
6
SMA Solar Technology AG
• Parts of a PV plant (such as cables) possibly
not identifiable because of smoke
• Perhaps not enough space to keep distances
due space constraints
• Recommendation:
Avoid touching hazardous DC voltage
inside a building during fire
7
Scenarios: Firefighting inside a building
Source :Homepage FireDepartment Munich
SMA Solar Technology AG
• Immersed DC installations in case of flooding
Probable: short-circuit caused by water in inverter
No risk of electric shock
• Entry of water into components of one polarity
(e.g. connectors)
• Electric potential of water
Minimal chance of electric shock if a second fault
is
touched simultaneously
8
Scenarios: Flooding
Source :Homepage FireDepartment Munich
SMA Solar Technology AG
• Accident involving people in the area of the generator
• E.g. car crashes into a building with integrated PV plant
• Cells and modules are still operating due to ongoing illumination
• Rescue operations in the area of the generator
• Measures at module level or at SELV level
• Likelihood is minimal
• Potential threat e.g. at plants along roads
9
Scenarios: Rescue operations near a generator
SMA Solar Technology AG
1
Firefighting operations with and without PV installations
2
3
Situation
4
5
Firefighting procedures during nighttime
Scenarios
Conclusion and outlook
Agenda
10
SMA Solar Technology AG
1. First attack and rescue operations, when the building is still not isolated
from the grid
• Following standard rules for firefighting and rescue operations at electric
plants under voltage
• Mostly protection devices have isolated the circuits under voltage
• Risk of electric shock very small
11
What is the firefighting procedure without PV installations?
SMA Solar Technology AG
2. After first activities, the firemen attempt to isolate the affected circuits.
• Circuit breakers are switched off
• Without checking if the circuit is voltage-free or not
> situation is still unclear
> But in most cases the firemen trust in the isolated system
3. After an electrician has checked the situation, the system is “officially“ isolated
• Now the system is safe
• The firemen can work without the limitations for systems under voltage
12
What is the firefighting procedure without PV installations?
SMA Solar Technology AG
Firefighting under uncertain conditions
Presumed isolation of circuits
Circuits are checked
Safe operation without limitations
13
What is the firefighting procedure without PV installations?
SMA Solar Technology AG
1. First attack and rescue operations, when the building is still not isolated from the
grid
• Following standard rules for firefighting and rescue operations at electric
plants under voltage
• Until this point, it is still the same!
• Hence the situation is nearly similar
• In PV systems no protection devices have isolated the circuits
> Chance of electric shock is higher
• In ungrounded systems the risk is reduced a lot,
> because of a minimal chance that both poles are touched simultaneously
• First attack under rules for firefighting electric plants
> With a higher risk to touch a dangerous voltage14
What is the firefighting procedure with PV installations?
SMA Solar Technology AG
2. After first activities, the firemen attempt to isolate the affected circuits.
• At PV systems this is usually not possible
• In comparison to a building without PV
> the firemen still don‘t trust in the system
3. After an electrician has checked the situation, the system is “officially“
isolated
• An electrician has to isolate at the modules and check the safety of the
system
• This procedure requires more time
• Now the system is safe
• The firemen can work without the limitations for systems under voltage
15
What is the firefighting procedure with PV installations?
SMA Solar Technology AG
Same, but changed risks
Usually not possible
Requires more time
Same
Firefighting under uncertain conditions
Presumed isolation of circuits
Circuits are checked
Safe operation without limitations
Without PV installations With PV installations
16
What is the firefighting procedure with PV installations?
SMA Solar Technology AG
• Additional measures can reduce risks and time delay
• Create the same level of safety as buildings without VP installations
> see following presentation from David Wedepohl, BSW
17
Additional steps can reduce differences
SMA Solar Technology AG
1
Firefighting procedures during nighttime
2
3 Firefighting operations with and without PV installations
4
5
Situation
Scenarios
Conclusion and outlook
Agenda
18
SMA Solar Technology AG
• There are often discussions about risks when
fighting fire at nighttime
• Are there “dangerous“ voltages
over 120V DC because of artificial
illumination?
• Are the risks the same as during daytime?
• A PV cell is a source for a current!
• The maximum current is limited by lighting
• Only a limited current possible over a body
• Tests in Switzerland and France showed
that it is almost impossible to get a current
at dangerous levels
Firefighting buildings with PV installations: “busting a myth”
SOURCE: CAMPAGNE DE TESTS NOCTURNES SUR LA PLATEFORME
PHOTOVOLTAÏQUE QUALIPHOTON® DE TRANSÉNERGIE; G. Moine,
M.-A.-Serve, TRANSENERGIE
VOLTAGE
CURRENT
Irradiance
19
SMA Solar Technology AG
1
Conclusion and outlook
2
3 Firefighting operations with and without PV installations
4
5
Firefighting procedures during nighttime
Scenarios
Situation
Agenda
20
SMA Solar Technology AG
• Correctly installed PV systems can be extinguished in case of a fire
• Physics are the same – worldwide
• But national differences in tactics and rules for firefighting
• German experience: Missing information and rules for this issue in time
• Escalation in media and press
• Creating confusion at the fire departments
• Resulting in wrong behavior
Need for rules for firefighting PV
“Translating“ specific characteristics of PV systems into rules for firemen
In comparison to similar situations (USV, unclear situations, electric plants, …)
To find consistent standards
Conclusion and outlook
21