Panels being covered in volcanic ash can cause several problems – as has been seen recently with ongoing eruption in the Canary Islands. The weight of the ash may be too much for the structure to bear, sharp ash particles or small stones within the ash can scratch module glass, and acids or sulfur compounds contained in the ash can cause corrosion on the backsheet.
More than a month has passed since the eruption of the Dorsal de Cumbre Viejo volcano on the island of La Palma began, at 2:13 PM on September 19th. Today, lava has spread from the volcano near the town of El Paraíso in the municipality of El Paso, to reach the urban are of La Laguna.
In the Las Manchas area of El Paso there sits 1 MW PV plant which was inaugurated in 2008, develop d by Gamesa Solar and later acquired by U.S. based investment fund First Reserve Corporation. The plant occupies 1.7 hectares of land and, according to a statement issued by Gamesa shortly after its inauguration, consists of some 5,000 PV modules. Today, these modules have been covered by up to one meter of ash spewed from the volcano.
According to online news site Nius, firefighters have been trying to clean the rooftops of nearby houses to prevent wind from blowing even more ash onto the panels, and they are waiting for the eruption to calm before they can return to the site and begin cleaning and evaluating the state of the PV system. “Only then can the losses incurred be valued,” states the article from Nius. “Its owners are aware that it is likely they will have to rebuild the project from scratch.”
Surveying the damage
At pv magazine we have frequently discussed the effects of extreme heat on panels and their performance, as well the effect of heavy loads (more commonly snow) resting on the modules, including in Spain where the winter storm Filomena left a third of the country blanketed in white earlier this year.
But what happens when solar panels are completely covered by volcanic ash? “In principle, the panels should not be considered lost, a meter of snow doesn’t leave them completely unusable either,” explains Asier Ukar, senior consultant at PI Berlin and the managing director of its Spanish subsidiary, PI Berlin S.L.
Ukar goes on to say, however, that the ash may cause several long-term problems for the PV project: the sheer weight of it could damage the mounting structure; sharp particles or stones mixed in could scratch the module glass; and the ash might contain aggressive compounds such as acids or sulfides that cause backsheet corrosion.
“All of this will become clear once the ash can be removed,” continues Ukar. The panels should be able to support between 2,400 and 5,400 pascals of pressure, depending on the standard they have been tested to. “If the ash is light, there should be no problem,” he adds.
Scratches to glass would also negatively affect performance, but Ukar believes this would be unlikely to put the project out of commission entirely, and would simply lead to more transmission losses of light through the glass.
The possibility of backsheet corrosion would also depend on how long the ash remains before it can be cleaned up, but Ukar says this “should not be a serious issue, as long as the ash is removed soon, since in principle the panels are only covered from the front.”
He adds that since the entire project is equally covered in ash, formation of hotspots should not be a problem. “Honestly, I don’t see it as serious,” he concludes.
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Source: pv magazine