A power plant based on the sun is normally said to be a long-term, secure investment. When completed, the implication is that the most challenging phase is over, and the plant will silently produce thoroughly clean energy for many years to come. In practice, however, the completion of the plant represents the start of the most critical phase in the plant’s life. During the ensuing 25 years, the actual performance, integrity, or value for money generated by the plant will be less a function of its construction, but rather a reflection of how the plant is operated.
A good contract for operations and maintenance (O&M) over a period of 25 years understands this. It’s not a contract for supplying a service, but a strategy for the asset’s life, and normally this is broken down into three distinct contract phases: early operating life, steady-state operations, and end-of-life/repower.
Phase 1: Initial period (Years 1–5)
The initial years of its operation are very important. This phase mainly begins with the stabilisation of the plant and working on issues in the early stages.
O&M services would begin with commissioning support and punch-list resolution, to ensure that all systems are functioning as designed and residual defects from the construction, or punch-list items, are addressed in a timely manner. At the same time, the O&M company would be responsible for fulfilling original equipment manufacturers’ warranties for major components such as modules and inverters.
Another area of equal importance is establishing performance baseline. The process involves collecting information about a plant’s operations to establish how it functions. The information serves as a point of comparison when a plant performs poorly in the future.
The major activity prevalent in this phase is corrective maintenance work. Failures in the beginning stages of equipment life, related to applications and manufacturing deficiencies, are corrected using Rapid Response actions. Failure to correct problems in the early stages leads to an escalation of a small problem becoming a serious operational concern in equipment life.
Phase 2: Steady-state period (Years 6–20)
Once the plant reaches operational maturity, the O&M strategy moves from stabilisation to optimisation. The aim in this long middle phase is to maximise availability, minimise downtime, and preserve asset value.
Preventive maintenance therefore becomes the backbone of operations. Regular inspections, module cleaning, electrical testing, thermal imaging, and IV curve analysis are done to identify risks before they result in failures. Performance monitoring software provides real-time visibility to generation data and allows quick action to be taken on strings or components that are not performing well.
Many long-term contracts have availability or performance guarantees over the life of that contract. These provisions better align the O&M provider’s incentives with the owner’s revenue objectives, ensuring a consistent focus on uptime and efficiency.
Component replacement also becomes routine. Some inverter parts, monitoring hardware, and auxiliary systems have relatively short lifespans and need to be replaced in a planned and cost-controlled fashion. Cybersecurity and data management also become more important as the monitoring platforms and grid interfaces become more sophisticated and require continuous attention in order to protect the integrity of the data.
Phase 3: End-of-life and repowering (Years 21–25+)
Once the asset has come near the end of its original design life, the concern then shifts to long-term plans. Aging of the component adds to corrective maintenance requirements, and attention is shifted to its performance trends.
Degradation analysis informs owners how actual production has deviated from initial production expectations. The average degradation of solar cells is estimated to be 0.5 to 0.8 percent per year, and after 25 years, it is estimated to be functioning at an estimated 80 to 85 percent of its capacity.
In this step, a strategic role is played by the O&M service provider. These could be repowering through upgrading their constituent parts, especially inverters or modules, in order to continue production. In other cases, they implement life extension strategies that allow them to operate on a reduced capacity or decommission.
Why O&M discipline matters
Even the worst O&M failures are rarely event driven. Rather, they creep up through loosely secured fasteners, corroded material, drainage problems, and missing inspection records. Solar support structures, having traditionally been viewed as static assets, continue to be subjected to the forces of wind cycles, thermal movement, and water. Disciplined inspection and preventive maintainability practices help to keep minor issues from adding up to bigger problems.
Over the long term, structural problems will influence the performance, module quality, and insurance integrity. Highly disciplined O&M projects ensure mechanical system integrity, reliability, and predictability of revenue, and thus lender and investor confidence remain intact.
A solar plant is no “set it and forget it” kind of asset by any means. In fact, an effective 25-year O&M contract ensures that the asset is treated like a living thing that needs some foresight, data-driven decision making, and care on a consistent basis. It is ultimately this kind of operating discipline that makes all the difference between a solar asset delivering on its promise of stable returns over its lifespan and underperforming years before its expected lifespan even ends.
