No longer an experimental technology, the total generating capacity of utility-scale photovoltaic (PV) power plants exceeded 60 gigawatts (GW) by the end of 2015. With many utility-scale PV power projects currently under development around the world, more than 100 GW of power generating capacity is likely by the end of this year.

This utility-scale PV power has been adopted at a quick pace over the last decade. Lacking the long operational history of fossil fuel power, the industry needed to establish standardized guidance for operations and maintenance (O&M) services derived from a cross-section of plant operational experiences. And in June 2016, after 12 months of work by a task force comprising senior executives from across the global supply chain, SolarPower Europe unveiled its first version of the “O&M Best Practices Guidelines.”

“In the first couple of years of the utility-scale PV power era, operations and maintenance focused on simple tasks like cleaning modules and mowing,” noted Bengt Jaeckel, a UL Principal Engineer for Photovoltaic and a member of the guidelines’ task force. “Now, this is changing as the connection between O&M and profitability is better understood. When components break down, there’s downtime; and three days of downtime in a year could be much more than a 1 percent yield loss, already significantly impacting the profitability of a power plant.”

Moreover, PV power plants are privately owned in most parts of the world and inevitably will change owners over their operational life. Buyers want to review the history of a plant’s power production and uptime records before purchasing any PV asset. Therefore, a well-maintained and well-operated PV plant is critical to holding its asset value.

As a provider of technical due diligence services during the development of solar power plants, UL recommends using these new guidelines for setting up the design, contracts and end-strategy during the initial phase of power plant planning. For its part, UL plans to implement the standardized practices in these guidelines into its own PV plant technical due diligence processes.

“We think they are good guidelines, and importantly, they are practical and have been developed by members of the industry,” added Jaeckel. “When engaged on future development projects, we intend to check what’s in an O&M contract against the O&M guidelines. It provides an independent reference, similar to International Electrotechnical Commission standards, that checks an O&M strategy using a more thorough, detailed due diligence process than has typically been done by those with limited experience in large-scale PV plant O&M.”

Adding to the complexity of PV power plant operations and maintenance is that each country has its own regulations requiring compliance. For example, most countries have grid-supporting requirements that enable operators to remotely reduce output from a PV power plant to the grid if there is too much production at a particular time. This keeps the grid stable and reliable.

Each country not only has different grid function requirements, but also has multiple grid operators with different guidelines. Many regions have highly interconnected grids between countries, e.g., in Europe, high-voltage transmission grid regulations have been developed by ENTSO-E (the European Network of Transmission System Operators for Electricity). The new O&M guidelines include “checklists” to help operators stay on track amid this high level of operational complexity.

With rapid ongoing innovation of PV technology coupled with extensive learning being gained from relatively new utility-scale implementations, it won’t be long before these new guidelines will need to be updated. Task Force 2.0 will be convening in late fall or early winter of this year, with plans to publish updated guidelines by the end of 2017 or early 2018. UL will again be at the table sharing its expertise.