Dec 5, 2014 - FIRE IGNITION AND SPREAD ANALYSIS ON PHOTOVOLTAIC ... FEU Meeting 1/2011 Conference, Cyprus http://www.ifv.nl/kennisplein/Documents/20110525-feu-ppt-photovoltaicfires.pdf ... Ignition Handbook, V.Babrauskas.
FIRE IGNITION AND SPREAD ANALYSIS ON PHOTOVOLTAIC BUILDING ROOFS V. Puccia, P. Cancelliere, & M. Caciolai Ministry of Interior, Italian National Fire Brigades and Services (CNVVF) Introduction Photovoltaic technologies represent one of the most diffused green energy source. Moreover, various accidents resulted in large fires on roof mounted photovoltaic plants, with the ignition of the building covering and the spread of fire inside the building throughout the roof openings.
Main PV causes of fire ignition
FIRE RISK in PHOTOVOLTAIC (PV) SYSTEMS:
•Resistive (Joule) heat release on PV modules
- As a cause of fire … mechanisms of fire ignition … electrical fire ignition (overload, short circuit, arcing, hot spot, mismatch)
•Mismatch on single or multiple cells
- As a victim of a fire because of an external fire … it
•DC Arcing
contributes (panels or PV modules) to fire spread … performances referred principally to 479
500
463
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300 250 200
136
100
PV MODULE HOT SPOT MECHANISMS
66
50 0
HOT SPOT EVIDENCE
•HOT SPOT
ble to turn off the whole power system in order to guarantee that all the components are de-energized while PV module and panels are exposed to solar or artificial light … Then …. electrical hazards to firefighters involved in the mitigation of a fire concerning photovoltaic modules!
350
150
• bypass and string diodes
PV panels (backsheets) - Furthermore … during a PV fire event it is not possi-
382
400
•Reverse currents
reaction to fire of
1
2
3
2002
2003
2004
8
13
2005
2006
34
26
2007
2008
2009
2010
2011
2012
2013
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2015
According to a recent survey of the Italian National Fire Brigade (Italy), around 2500 fire-related accidents have occurred in the nearly 650.000 PV plants currently installed in Italy
Fire Investigation evidences Junction Box Fire Ignition Mechanisms
Ribbon to cell Interconnections Failure [1]
Ribbon Connections with evidence of thermal effect of overcurrents
The effect of a DC arc induced during a test (Courtesy of Trento Fire
Holes in the metallic upper sheet of a sandwich roof panel, effect of DC ground arcing
.
Aligned bubbles on ribbon, Joule's Effect of internal over currents rather than convective heat transfer from fire smokes
Training School)
Comparison of the electric power generated from two twin arrays of the PV plant identify over any doubt the origin power inv3-inv2
1.5
-0.5 0
5
10
15
20
25
30
35
-2.5
kW
-4.5 power inv3-inv2
-6.5
-8.5 9500,00
-10.5 9000,00
-12.5 giorni
Post incident inverter data analysis
8500,00
inverter 2 inverter 3
8000,00
inverter 1
7500,00
7000,00
6500,00 0
5
10
15
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25
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35
gi orni
A roof fire ignited from a PV plant: relevant dark smoke plumes are a source or public concerns with regard to pollution and public health issues
Conclusions An accurate survey of the construction products once installed coupled with the simplest scenarios of PV plant fault could suggest, yet at stage of feasibility study, most of elements for a fire risk assessment, also with regard to cost benefit economic evaluation. The availability of remote control system could represent an early alarm of ground DC arcing, and the advances on standardization on Arc Fault Circuit Interrupters will soon give a reliable solution for fire risk reduction. The fire investigation evidences produced a growing perception and understanding of this particular scenario, both in the field of fire prevention and of firefighting operations; on the other hand the public incentives to green energy generation conducted to a huge number of PV roofs, with a challenge for the regulator authority (the National Fire Corp Technical Directorate for fire prevention) to develop guidelines for safe PV plant erection and installation.
References
EPIA - global market outlook for photovoltaic 2014-2018 – www.epia.org/news/publications/global-market-outlook-for-photovoltaics-2014-2018/
Firefighter Safety and Photovoltaic Installations Research Project prepared by Robert Backstrom Research Engineer, Fire Hazard Group, Corporate Research and David A. Dini, P.E. Research Engineer, Electrical Hazard Group, Corporate Research - Issue Date: November 29, 2011 - Underwriters Laboratories Inc (UL).
PV electrical plants fire risk assessment and mitigation according to the Italian national fire services guidelines, Piergiacomo Cancelliere, FIRE AND MATERIALS Article first published online : 5 DEC 2014, DOI: 10.1002/fam.2290
V.Puccia, Fire Involving Photovoltaic Plants, FEU Meeting 1/2011 Conference, Cyprus http://www.ifv.nl/kennisplein/Documents/20110525-feu-ppt-photovoltaicfires.pdf
V.Puccia, L.Marmo, L.Fiorentini, E.Danzi Fire risk analysis of photovoltaic plants 47th ESReDA Seminar. Warsaw 2014
V.Puccia, L.Marmo, L.Fiorentini, E.Danzi, SFPE Magazine May 2015 Issue 99: Fires in Photovoltaic Systems: Lessons Learned from Fire Investigations in Italy
Ignition Handbook, V.Babrauskas
K. Prasad, N. Marsh, M. Nyden, T. Ohlemille ,M. Zammarano ,Numerical simulation of fire spread on polyurethane foam slabs, Fire Research Division BFRL, NIST Annual Fire Conference, 2009
CEN/TS 1187:2012 Test methods for external fire exposure to roofs;
A.P. Mouritz A.G. Gibson ,Fire Properties of Polymer Composite Materials, , Springer Verlag
EN 13501-5 : Fire classification of construction products as building elements - Part 5 Classification using data from external fire exposure to roof test;
I.Kotthoffr,R. Walterf, W.Wittbecker ,Fire Performance Of Polyurethane Steel Deckroofing, , ISOPA
Kohler M. Arcing potential in contacts and plugs, Multi-Contact AG International Workshop Burgdorf CH – 31 october 2007;
Solar America Board for Codes and Standards (Solar ABCs) Report,
Kremer P. Arcing potential in fuses: missing standards for adequate testing of fuses in PV application , - Head of DKE K373 and K221.1.4 (VDE and DIN) www.solarabcs.org
Solar America Board for Codes and Standards (Solar ABCs) Impacts on Photovoltaic Installations of Changes to the 2012 International Codes www.iccsafe.org
www.solarabcs.org/interimflammability
