Hearing debates solutions to mitigate fire risks in PV systems

The Mines and Energy Committee of the Chamber of Deputies discussed, this Wednesday (6), the risks of fire in photovoltaic systems. O debate was requested by deputy Fabio Schiochet (União-SC).

The parliamentarian highlighted that such a high number of generating units requires special attention to safety aspects.

“LIGABOM (National Council of Military Fire Brigades of Brazil), which is fully aware of the occurrence of fires in this type of electrical installation, warns of the need to improve the standards that govern the matter”, he stated.

Firefighters request standards to contain fires in PV systems

Colonel Alexandre Gomes, from LIGABOM, was present at the meeting and highlighted that they are preparing standards that guarantee everyone's safety, both for users, in their homes and large buildings, and for firefighters in the event of an accident in which they have to act.

“Therefore, the integration of all interested parties is very important. Solar energy is an excellent option for the country's future and for the environment. We are constantly focusing on studying what comes in the future on this matter”, he added.

Colonel Goes, from the CBMDF (Military Fire Department of the Federal District) also participated in the meeting and emphasized that the future lies in renewable technology. “It’s a path of no return. It is up to us to regulate it to be a path of no return with safety, profitability and effectiveness”.

“We do have to bring security to the system, but we cannot turn it into a bunker, where it will become so secure that its use and application by the user will be unfeasible. There must be a work area. We cannot be in either the white or black zone, we need to be in the gray zone, which is the study objective of this commission”, he pointed out.

Main causes of fires in PV systems

During the hearing, Lieutenant BM Evandro Maroni, from CBMMG (Minas Gerais Fire Department), pointed out the main causes of fires in solar plants, according to the article Fire safety and solar electric/photovoltaic systems. Are they:

• Technical problems in installation/maintenance;
• Incorrectly specified/designed equipment;
• Failure of defective products/equipment

Regarding the main risks, he listed batteries, electric arc, direct current and lack of knowledge of the existence of the risk.

“In view of this scenario, it is essential that professionals in the field have technical training for a correct and effective installation of the plant and that there is signage indicating the existence of modules in the building”, he exemplified.

How to avoid fires in photovoltaic projects?

Maroni also reinforced the need for equipment to have rapid shutdown (quick shutdown device) and detection and interruption of arc faults.

“It is essential to require the requirements, tests and trials for the equipment that makes up photovoltaic installations, as provided for in Inmetro Ordinance No. 140/2022, with the previously exposed devices being added”, he concluded.

Inmetro work plan

Pedro Henrique Pereira, executive analyst at Inmetro (National Institute of Metrology, Quality and Technology), emphasized that they are looking to develop a joint work plan to help mitigate fires involving photovoltaic plants. Below are his suggestions.

• Data collection and systematic risk analysis: understanding the problem, technical approach and support for decision making;
• Improvements in technical regulations: inclusion of mandatory protection devices against electric arcs, as well as conformity assessment for cables and connectors and for photovoltaic installations;
• Working group involving the production sector, experts and the fire department: preparation of guides and recommendations, training and qualification of firefighting professionals;
• Sectoral quality programs: quality of photovoltaic installations, cables and connectors;
• Development of new technical standards;
• Guide to good practices for the safety of photovoltaic systems.

Throughout the debate, the expert also showed a graphic which relates mortality rates in the generation of 1 TWh. “Deaths may be related to accidents or air pollution. At the top we can see coal, oil and at the bottom solar with the lowest mortality rate”, he highlighted.

ABSOLAR market research

Rodrigo Sauaia, CEO of ABSOLAR (Brazilian Association of Solar Photovoltaic Energy), reported that they carried out a survey with members to check the market's and companies' views on solutions that can be advanced to strengthen the safety of photovoltaic systems. See below.

1. Certification of professionals and companies (87,2%);
2. Certification of professional training and qualification courses (79.5%);
3. Improve and/or create more training and training courses for professionals (71.8%);
4. Continuous promotion of studies to support decisions and propose increasingly safe and viable requirements (69.2%);
5. Improve and create ABNT NBRs standards (66.7%);
6. Inspection by CREA/CONFEA (56.4%);
7. Installation of shutdown or de-energize mechanisms for direct current circuits (48.7%);
8. Installation of mechanisms for detecting and interrupting electric arcs in direct current circuits (46.2%);
9. Spacing rules between photovoltaic modules (41%);
10. Inspection by the distributor (38.5%).

Finally, Sauaia also announced at the meeting ABSOLAR's proposals to help mitigate the risk of fires in solar plants. Among them are:

• Include in Inmetro's RTQ (Technical Quality Requirements) and RAC (Conformity Assessment Requirements) the mandatory AFCI on inverters, establishing a transition period of 6 months to structure the respective conformity tests and adapt the sector;
• Guide/manual on fire safety in PV systems and how to combat them: preparation, together with ABNT's specialized technical groups, of PR (Recommended Practice) on the topic, in partnership with the Brazilian Fire Department;
• Voluntary certification of companies in the solar sector;
• Strengthening quality requirements for PV cables and connectors;
• Distance between rows (strings) of PV modules: define, via the ABNT standard, access conditions and appropriate physical space for operation, maintenance and firefighting activities;
• Rapid shutdown or MLPE (Module-Level Power Electronics): Inmetro – carry out AIR (Regulatory Impact Analysis), regarding the use of these components in PV systems.