As solar farms age, additional maintenance activities and older equipment drive up operational costs. Annual Preventive Maintenance Inspections (PMIs) play a critical role in monitoring production expectations, identifying these equipment issues, as well as guiding key maintenance and budget decisions. For owners of solar projects, the PMI is the most important line item in most solar O&M contacts. Although the PMI scope of work is often standardized and relatively straightforward, SolRiver’s team frequently sees other IPPs overlook valuable opportunities in the PMI. This article is not about amending your O&M contracts but about helping asset owners get the most out of their annual PMI (if you’d like to learn more, check out our Asset Management Services).
Basic PMI Structure
Understanding how the PMI is structured, and how to make it work harder for your project is the first step to reversing that trend. Most owners of Distributed Generation (DG) solar projects have an annual PMI in their O&M contracts. In these contracts, Owners pay a large fee to their contractor in exchange for an annual inspection of their solar farm. In a standard agreement, the contractor likely agrees to inspect all key equipment, walk the farm, and deliver a detailed report covering everything that was investigated and discovered during the annual inspection. This structure is standard across the industry and PMI is usually the largest expense in any solar O&M contract. Unfortunately, many owners are not maximizing their ROI of this cost and miss out on capturing the full value of the PMI.
Four Issues Worth Attention
There are four common mistakes Owners make when evaluating the PMI scope of work: (1) scheduling the PMI at the wrong time (2) not updating equipment user manuals (3) not including repairs (4) not visiting the site afterwards. Fortunately, all four are simple changes Owners can make.
Mistake 1: Scheduling the PMI at the wrong time
A solar farm’s PMI is best scheduled in the spring, before peak summer production. Doing so maximizes the ability for the farm to produce during the highest production months from May – September. Conducting the PMI during the summer risks downtime loss during your highest productions opportunities. Conducting the PMI during the Fall leaves too much time for equipment failures to occur before the high irradiance seasons return. Conducting the PMI during the winter typically won’t make sense due to how low expected production is as owner usually want to avoid high costs during low revenue periods. Scheduling your PMI to occur in the spring is a simple measure you can implement that can help keep your project operating efficiently during the highest revenue periods.
Mistake 2: Not updating equipment user manuals
The PMI should always follow the latest equipment manual inspection instructions and recommendations. For example, Inverter and Combiner Box equipment manuals are periodically updated, but contractors may not be aware of these updates, and they are often left out of contracts. This leaves room for inadequate inspections and poor upkeep of key equipment. Additionally, solar technology and equipment is rapidly developing and improving and much of the electrical equipment we see on farms today may soon become obsolete. To protect your farms, ensuring the equipment is being cleaned, repaired, and maintained per the evolving manufacturer’s instructions will be key to system longevity and successful warranty claims. In your O&M contract, referencing the latest user manuals for PMI inspections might just be the difference between a system’s useful life of 25 years or 30 years.
Mistake 3: Not including repairs
Contractors will often treat the PMI as site walk inspection and won’t make any repairs while on-site for the PMI. This is a missed opportunity for owners to see system production improvements. In your O&M contract, including responsibilities to make repairs to equipment as issues are identified enables immediate system improvements. Remember, the PMI is often the largest maintenance cost that owners incur. To capitalize on this, owners should ensure this PMI truck roll includes responsibilities for the contractor to make repairs to the site. For example, if conducting IR scans of combiner boxes is part of the PMI scope, you could also define a responsibility to retorque loose connections as part of the inspection.
Mistake 4: No follow up inspection
An important role as owners is to review the contractors’ work. Visiting the site after the contractor submits the PMI will often reveal a multitude of missed details. Capturing these details by visiting the sites and inspecting them yourselves, holds the contractor accountable and maximizes the value of PMI. The cost-benefit analysis of an owner site visit is highly favorable and can be overlooked in our industry. Additionally, establishing a relationship with your contractor that includes a clear expectation of physical oversight, promotes higher production and long-term reliability.
