Watch your assets: Solar O&M tips for maximizing site ROI

The prodigious growth of solar power in the United States has turned what was once a boutique industry into a multibillion-dollar asset class. Cumulative installed solar PV capacity now exceeds 20 GW, with thousands of projects scattered across the country.

With gigawatts now in play, this burgeoning stable of solar asset investments needs to be properly operated, maintained and managed. Commercial solar system owners, building hosts and other stakeholders require professional operations and maintenance (O&M) services for each solar project to realize their full value potential. PV systems that do not have scheduled maintenance programs to support the product and power production do not typically provide the best ROI for the customer.

From Cost-Center to Value-Add

Until recently, the prevailing view of commercial solar O&M focused mostly on the more janitorial and repair sides of the service: keeping the vegetation trimmed, cleaning modules, replacing faulty inverters and monitoring the performance of the PV array. O&M has been seen by some developers and EPC firms as an annoying cost center or necessary evil, one that could be downplayed (and underbudgeted) to make a project pencil out in the face of constant downward cost pressures. This compunction to cut construction — and services — costs to enhance short-term profits can have a negative impact on the longer-term operational health of the system.

The largest hidden cost to underappreciating O&M is failed power production expectations. Customers plan, forecast and budget based on the expected power that is estimated during design and construction. A PV developer’s future financing can be seriously affected by an underperforming project. Costs for expensive material repairs and additional resources needed to manage and repair the asset can add up quickly.

A growing number of investors, EPCs and asset owners now realize that O&M and related services require a more holistic, value-oriented approach, that is baked into the system design and procurement stages and continues forward  through the life of the project. To get the maximum return on investment, the combination of a well-designed, well-built system and a prudent O&M plan offer the best chance for success.

The operational success of a commercial solar power plant requires that all of the parties involved — system owner, building host, O&M team and monitoring firm — agree to clearly defined roles. There are many reasonable ways to slice responsibilities, and that’s why all parties need to know their roles and expectations within the larger project maintenance strategy.

RELATED: Fixed-Tilt System vs. Single-Axis Tracker O&M Comparison 

From Reactive to Proactive

Developing a proactive, site-specific O&M schedule is the first step to maximizing the long-term value of a new solar project. An ounce of prevention can save you a pound of maintenance costs. The key to doing this effectively is to determine exactly how much preventive service should be done to maximize long-term system value.

For example, one of the most important — and commonly missed — preventive maintenance services is inverter filter cleaning. Manufacturers typically require an annual preventive cleaning of filters to maintain warranty status. Just as dirty panels produce significantly less than clean panels, dirty inverter filters reduce an inverter’s efficiency and can ultimately suffocate the inverter. Failure to schedule regular inverter maintenance could lead to project downtime and significant rework expenses.

Half the battle is knowing what potential issues to look for and expect. Not every solar power system is created equally, and over the years we have seen some patterns emerge in the types of issues that impact system performance, especially among arrays built in the earlier part of the solar boom. An asset owner’s approach to these issues will help determine the long-term profitability of the investment.

One of the more common issues we have seen emerge is ground faults: Poor wire management often results in the inverter receiving a ground fault that shuts it down. In order to fix the problem, we send an electrician out to the site to find the ground fault and then replace the fuse on the inverter to get the system back online.

In some situations, bad wire management can lead to ground fault after ground fault, running up long-term bills and reducing a project’s profitability. This is true for many other O&M issues as well. If a project was not designed and built properly, the asset owners could spend years battling recurring O&M problems. Ultimately, the best way to avoid unnecessary O&M work is to ensure that the system is built right the first time.

The Value of Documentation

Reputable service providers will always provide reports upon completion of any maintenance service. This is vital. Effective O&M documentation that details the scope, schedule and service history of a system can save the manager or owner time and money.

Maintenance documentation can be an essential requirement when addressing warranty coverage, and many warranty holders will not provide service without it. Though documentation may require more involvement on the owner or manager’s side, it reduces risk and allows greater scrutiny and protection of your investment.

Wayne Williford is the director of O&M business development for REC Solar.

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