The growing adoption of Photovoltaic systems in different climatic conditions around the world indicated factors that could contribute to the occurrence of failures in solar s.
Knowing this fact, the IEA-PVPS (International Energy Agency Photovoltaic Energy System Program) published a report with the aim of providing comprehensive guidance for O&M services (Operation and Maintenance) in different climatic zones.
The first four are for conditions that widely prevail in large parts of the world: moderate, hot and dry, hot and humid and deserts in high altitude areas. In addition to these, they analyzed the extreme conditions, such as regions prone to flooding, cyclones and snow.
“These guidelines can help engineers and designers of photovoltaic installations, financiers and investors in deg and maintaining installations, as well as determining operational risk related to investment decisions,” said the IEA.
Below are the essential practical guidelines for the climatic zones studied, according to the published research.
Seasoned: An on-site assessment of vegetation, wildlife and livestock must be carried out. Mowing the lawn must be combined with an inspection of the condition of the photovoltaic modules to decide whether cleaning and/or corrective maintenance actions are necessary.
“In industrial environments, s can develop unexpected deterioration. Particular attention should be paid to the selection of cleaning products and it is advisable to follow expert recommendations on suitable products”, they reported.
Warm and dry: wildlife risk assessments must be made, appropriate planning for visits to typically remote locations (hydration, anti-venom procedures and PPE). “The risks, for example, include insects that can cause short circuits or arc flashes.”
“The typically remote nature in hot, dry climates implies significant travel and preparedness requirements, due to logistical risks in of providing these facilities as well as access to emergency medical care. Temperature extremes and exposure to salt also increase material degradation in modules, frames, junction boxes and transmission cables”, they pointed out.
Hot and humid: Wildlife intrusion into ground-mounted systems, particularly rodents and snakes, can cause failures in photovoltaic components and electrical systems, as well as having an impact on soiling.
According to the IEA, cleaning the boards can reduce production losses by up to 6-8% during the summer months. “Adequate ventilation during the hot months is also crucial for the good operating conditions of the inverters.”
Prone to flooding: According to the research, it is important to note that photovoltaic systems are not typically designed with flood resistance. However, climate change and extreme events, combined with limited land availability in certain parts of the world, mean that some plants are built in areas that flood 2-3 times a year.
“Actions to prevent damage include turning off the plant in anticipation of flooding and only turning it back on after technical inspection. Floods can damage module mounting clips, s, the lamination on s and even boot foundations,” they commented.
Regarding dirt, the report indicated that it is particularly difficult to repair when water has been on the modules for a long time. “Submerged inverters can also cause short circuits and cause burn/fire hazards.”
Cyclonic regions: damage caused by typhoons and cyclones typically affects modules and fastening structures. Glass breakage is also a particular problem in cyclonic regions, as is breakage of fastening parts, which has been observed due to elevations in air pressure.
Cellular cracks caused by deflection under strong wind loads can still occur. “Although national standards for wind loads are present in the US, Japan and EU, non-uniform mechanical load tests have not yet been launched due to a lack of experts and countries that are needed to form a design team.”
“It is therefore recommended to estimate the effects of winds using wind tunnel tests, ensuring that the structural connectors have sufficient strength and that the modules have sufficient resistance to lifting”, emphasized the experts from the International Energy Agency.
It is also recommended, in their view, to assess compliance with standards during construction, carry out periodic maintenance of all bolted connections, store sufficient repair parts and remove loose debris around the plant.
Snowy regions: Snow accumulation affects performance, as heavy snow loads make it difficult to transmit light to the cells and can damage the plates. A suggested limit for snow accumulation on s is 0,7m.
“Photovoltaic mounting structures can also be damaged by extremes between winter and summer temperatures. In this case, steel structures are preferred over aluminum. If active cleaning measures are implemented, such as brushing, care must be taken not to scratch the glass as well,” highlighted the report.
“Experiments have been carried out to heat photovoltaic modules by applying a controlled voltage forward to melt snow. This would require careful cargo control and the use of weather forecasts,” they highlighted.
O&M is key
The IEA concluded by saying a combination of well-designed O&M specifications, proactive monitoring systems and a flexible and adapted O&M regime that considers both climate impact on systems and possible changes to grid requirements are good practices to ensure that systems reach or even exceed their expected useful life.
“Reducing risks by ensuring that personnel are trained and equipped for O&M operations, as well as using forecasting to reduce potential downtime, also helps maintain PV installation performance according to specifications,” concluded the study.
Check it out in the 11th edition of the magazine Canal Solar an exclusive report on O&M for photovoltaic plants, which presents the concept, importance and most common problems encountered. Access the link.
