Fire Protection for Roofs with Photovoltaic Panels
PVProtect from Minimax is the first fire protection system with VdS certification designed specifically for roofs with photovoltaic panels, as stated by the manufacturer. Its holistic protection approach is conceived to detect fires early and fight them automatically. This helps to minimize the damage caused to the roof.
The roofs of many industrial and commercial buildings have already been equipped or retrofitted with photovoltaic panels over many years to make use of solar energy. A study by the green-tech company CarbonFreed showed that in the first six months of 2024 alone around 2,700 commercial solar systems with a total power of 980 megawatts were registered in Germany. The number of new systems is on track to exceed that of last year, which had already broken the record with 4,100 systems and a total power of 1.4 gigawatts.
While this growing number is good news for the energy transition, it also increases the potential for fires on the buildings on which these systems are installed. Combustible materials and sealants in the roof construction present the biggest problem: they support the quick spread of fires, which can lead to widespread damage.
Cables, sockets and electrical components are all potential sources of fire because they are constantly exposed to the elements and age quicker, wear out, or become damaged. The high currents that flow through these components can cause sparks and easily ignite a fire. Once the roof material has caught fire, it can quickly spread throughout the entire roof. The consequences can be significant damage to the facilities and follow-on costs due to interruption of business, repairs, and purchase of replacement parts, if not the total loss of the building.
Early Detection, Automatic Extinguishing
PVProtect helps to significantly minimize or completely prevent such damages by combining a holistic early detection approach with automatic firefighting. A linear heat detector with closely spaced sensors monitors the area below the photovoltaic system. If a fire starts, the sensors will register a suspicious rise in temperature and report this to the fire detection control panel. This activates the extinguishing system immediately and sounds the alarm onsite. The fire brigade is simultaneously alerted and the exact location of the fire reported.
Rapid firefighting with special PV nozzles enables water usage that corresponds to the risk, and prevents the fire from spreading. Thus, PVProtect safeguards not only the roof, but also the complete building against fire and consequential damage. The emergency services can go directly to the location of the fire and extinguish any remaining embers.
Areas of Application
PVProtect is designed for roofs with the usual sealants such as sealing strips made of plastic, bitumen, or other sealants containing bitumen, PUR sandwich elements (of all fire protection classes) as well as flammable roof sealants and roof construction components. The list of insulation materials includes mineral wools or other non-combustible insulation materials, PUR/PIR certified to B-s2-d0 as well as PUR/PS or other combustible insulation material. The system should not be used on roofs with vegetation near the photovoltaic system because these are most probably built on an absorbing substrate.
4 Questions to Thorsten Gieseke,
Extinguishing System Manager for Water Extinguishing Systems and Head of the Fire Protection Research Center at Minimax
GIT SECURITY: Mr. Gieseke, you introduced a product some time ago that addresses a highly topical problem: fire protection on roofs equipped with photovoltaic systems. Your solution is VdS certified. First of all, how high is the risk of fire in such environments – and how widespread are roofs that were built with combustible insulation? What do you estimate the number to be?
Thorsten Gieseke: Many existing buildings were retrofitted with photovoltaic systems years ago. There was no need to use non-combustible materials when these buildings were constructed, for example for the insulation material. That is why we see a significantly increased fire risk with such retrofitted systems when a fire breaks out on a roof because of a photovoltaic system. Our own tests have shown that even materials that are considered to be ‘fire safe’ can actually catch fire under these circumstances and must therefore be extinguished. The major danger with all these fires is that they are not detected and are able to burn their way through the whole roof. A fire can spread undetected below the top layer of the roof covering. This cannot be seen with the naked eye from a distance, and is a real danger. It can happen within minutes and is then not easily brought under control.
You have developed a holistic solution. Could you summarize how it works and its advantages over other systems?
Thorsten Gieseke: PVProtect is based on a simple but ingenious construction. A linear heat detection cable is laid over the entire area of the photovoltaic system and reports any unusual temperature increase to the fire detection control panel. This immediately alerts everyone nearby as well as the fire brigade. At the same time, the extinguishing system is activated so that firefighting starts automatically. The extinguishing water is led through pipes under the photovoltaic panels to the roof and spread by special PV nozzles. The big advantage of PVProtect is that the system fights the fire before the fire brigade arrives. This prevents the fire from spreading and minimizes potential fire damage. If you only run a detector cable, you know that there is a fire and can evacuate the premises, but the fire can spread without any containment and cause significant damage before the fire brigade arrive and extinguish it.
What conditions had to be fulfilled to achieve VdS certification, and what advantages does that bring for the customer?
Thorsten Gieseke: Many different extensive tests had to be carried out in various different scenarios before PVProtect received its system approval. The system passed all the tests without exception. This seal of approval will assure customers who install this system on their roof of its function and effectiveness. Customers can also receive discounts from their insurance companies when they install the system.
You introduced this extinguishing system at the end of last year. How has it been taken up by the market?
Thorsten Gieseke: PVProtect is very versatile. It is designed for all sorts of different roof materials and constructions; it can be installed on new buildings; it can equally well be retrofitted to existing buildings. The system is suitable both for buildings with a sprinkler system and also for those without. This is one reason why the system has been taken up very positively not only in Germany but also internationally.
