A. Haring PV & Fire Safety--Experinece in Germany

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


1 Situation

2

3 Firefighting operations with and without PV installations

4

5

Firefighting procedures during nighttime

Scenarios

Conclusion and outlook

Agenda

2


1 Situation

2


4

5


Scenarios


Agenda

3


• 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


1

Scenarios2


4

5


Situation


Agenda

5


• 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


• 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


• 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


• 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


1

Firefighting operations with and without PV installations

2

3

Situation

4

5


Scenarios


Agenda

10


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?


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



Firefighting under uncertain conditions

Presumed isolation of circuits

Circuits are checked

Safe operation without limitations

13



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?


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



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



• 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


1


2


4

5

Situation

Scenarios


Agenda

18


• 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


1


2


4

5


Scenarios

Situation

Agenda

20


• 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


21


Thank you for your attention!> Source: Homepage Fa. Energie-Concept