PV owners urged to use tech advances, retrofits to hike yield

Solar operators must capitalize on new panel coating and analytics technologies and optimize retrofit and repowering strategies to boost competitiveness, Mate Heisz, lead coordinator of new European solar O&M best practice guidelines, told New Energy Update.

As capital costs fall and subsidies end, solar plant owners are seeking to reduce operations and maintenance (O&M) costs to gain a competitive edge.

Technology advancements are offering owners new ways to maximize revenues and asset life spans.

Increased competition has driven down O&M prices but the quality of service can vary widely between suppliers.

Sustained price pressure and inadequate training can impact quality and many operators are not taking advantage of new data analytics technologies and advances in solar plant components, according to new guidelines by SolarPower Europe’s O&M Task Force due to be published in December.

Solar plant investors will need to invest in cutting-edge technologies and component replacements to maximize competitiveness against other generation types, Heisz, a Senior Advisor at SolarPower Europe and lead coordinator of the ‘Solar O&M Best Practice Guidelines Version 4.0,’ told New Energy Update.

Investments in areas such as smart plant monitoring, data-driven O&M, panel cleaning technologies and repowering will help operators maximize income in the coming years, Heisz said.

Higher yield

The new guidelines will include recommendations on solar module cleaning, a key cost component for utility-scale plants.

Advanced module cleaning technologies and schedule optimization are helping to cut O&M costs, Andy Walker, Senior Research Fellow at the National Renewable Energy Laboratory (NREL), told New Energy Update earlier this year.

Studies have found that greater frequency of cleaning after ploughing and pollen seasons can help to increase plant efficiency, Walker said.

                               US solar O&M costs by category (2018)

Source: U.S. National Renewable Energy Laboratory (NREL) 

In Qatar, where hard layers of dust and sand can form on modules, researchers have found that dust accumulation can lower solar output by 0.5% per day and on average one clean per month could be optimal. The Qatar findings should be applicable to other key solar regions affected by dust and sand, including much of the Middle East and North Africa (MENA), Southwest U.S., Chile, and parts of India and China.

For European operators, retrofit anti-soiling coatings for PV modules can have a significant impact on performance.

By reducing dirt build-up, these coatings can increase energy yield by up to 3% while also reducing cleaning costs, Heisz told New Energy Update.

In addition, new anti-reflective coatings can be retrofitted to operational panels to reduce energy losses and increase output, he said.

Plant upgrades

Repowering of solar plants or revamping/retrofitting of PV plant components can also offer significant returns on investment, the guidelines will say.

Falling costs and rapid advances in solar plant components have created “an economically feasible re-investment case,” Heisz said.

Ageing solar components lead to increased failure rates and newer equipment can offer longer warranties, greater reliability and lower O&M costs.

New components can offer “higher design flexibility and advanced features" that help reduce O&M costs, Heisz noted.

For example, improvements in inverter design and reliability have reduced O&M costs and suppliers are offering much longer warranties.

Revamping of components might take place between five and 12 years of operations, while repowering might take place after around 25 years assuming a 50-year projected lifespan, Ernesto Chieffo, Technical Director at Octopus Investments, told New Energy Update in 2018. Octopus manages 2 billion pounds ($2.5 billion) of renewable energy assets in Europe and is active in the solar repowering and retrofitting space.

“You can assume that the majority of the plants built in Spain, Germany and Italy are already matured for retrofitting/repowering,” Chieffo said.

Repowering also offers operators the ability to correct layout mistakes made in initial plant construction, Heisz said.

O&M teams are playing a growing role in the design of new projects. Developers are using learnings on operational efficiency and O&M contract arrangements to improve project efficiency.

Analytics edge

Advances in plant monitoring and data analytics capabilities are also helping solar plant operators increase uptime and reduce labor costs. Data-led predictive maintenance can reduce unplanned outages and spare parts risks and offers scaling advantages for larger fleets.

The solar O&M sector is rapidly moving towards the adoption of 'smarter' plant monitoring solutions based on remote technologies and advanced data mining, rather than staff inspection and data collection processes, Heisz noted.

In one example, drone technology is allowing operators to perform remote thermographic imaging of power plants, providing performance data which can be analysed almost instantly. U.S. power groups Duke Energy and Enel Green Power North America (EGPNA) have recently deployed AI-supported drone technology across solar assets to reduce inspection times and improve maintenance efficiency.

“Aerial inspections and their post-processing activities are evolving rapidly," Heisz said.

"Adopting new technologies quickly is of high strategic importance in today’s highly competitive market”, he said.

By Neil Ford