Repowering to the Rescue: How to Restore Productivity to Aging Utility-Scale Solar

Utility-scale solar projects are hitting mature lifecycle stages in large numbers. The industry has boomed in the past few decades, but this means those pioneering early projects are facing aging structures, component degradation, and productivity loss. 

Aging systems underperform by 5-10% below their initial P50 value, reducing ROI while increasing O&M costs. And due to massive technological advancements in solar since the turn of the century, 15+ year old projects just can’t measure up to new builds. 

But that doesn’t have to be the end of the story.

There is a way to make aging solar projects better and more powerful than ever: utility-scale repowering. 

Although many solar components are impacted by aging, the site itself, its interconnection to the grid, and much of the underlying infrastructure remain largely unchanged – and valuable. 

Repowering takes advantage of these elements, leaving them in place while upgrading key components such as modules, transformers, and tracking systems. This newer and better equipment corrects operational deficiencies, restores productivity, and maximizes returns from existing solar installations. 

For stakeholders, repowering is a welcome alternative to the cost and hassle of decommissioning the old projects and developing a new one from scratch. Upgrading modules, a tracking system, and/or transformers can return a project to its former glory and beyond - increasing output, ROI, and the system’s lifespan. 

An aging utility-scale solar project may not need full repowering to return to peak production. Replacing underperforming components isn’t a small task, and there may be other stop-gaps or solutions that asset owners and stakeholders can use first.

Regular performance monitoring can help determine whether or not repowering is the right choice, and the optimal timing and scope for a repowering project. If a project is hitting any of the below metrics or situations, it may be time to consider repowering: 

• A project is producing less than 90% of its original power output 

• Individual modules have degraded to produce less than 80% of their original capacity 

• Repairs are more common and more costly than before

• Existing components are discontinued, making it difficult to find replacement parts and perform repairs 

• There are more frequent, longer-lasting operational interruptions 

These signals typically mean that a system is nearing the end of its natural life, but it doesn’t mean that decommissioning is the only option. Tracking and analyzing these performance indicators will provide insight into the scope and cause of productivity loss. From there, a project team can determine the most effective upgrade pathway.

External factors may trigger the need for partial repowering, even if a site has some natural life left. For instance, a site built 10-15 years ago in a relatively open space may now be surrounded by tall buildings or older-growth trees that increase shading. Conversely, nearby building decommissions or tree-cutting may have opened up more space for modules. It’s important to consider how changes in a sites’ surroundings may impact its functioning. 

In addition, climate patterns have undergone significant changes over the last two decades. Projects in formerly quiet regions may now be at higher risk of floods, high winds, hurricanes, hailstorms, blizzards, or tornadoes.

If a site has been impacted by extreme weather, or its region is at increased risk, upgrading a system with more resilient components helps protect against these threats. For example, our Genius Trackers are designed and comprehensively tested to minimize potential system damage from high winds, hurricanes, dust storms, and heavy snow. They can easily be retrofitted into existing systems, ensuring that sites are ready for what’s ahead – not just yesterday’s weather report. 

Once it’s clear that repowering is the right solution, it’s important to choose components carefully. Repowering can do far more than restore an old system to its 2005 or 2010 era; it’s an opportunity to incorporate the most advanced and efficient new elements. 

For instance, today's advanced trackers incorporate precision sensors and actuators that dynamically optimize panel positioning throughout the day, minimizing shading and absorption losses while maximizing energy yield. Genius Tracker’s advanced technologies, such as intelligent Hail Stow™ and SmartStow™ features with optimized wind response protocols, are designed to stay resilient even in extreme weather conditions. Repowering a site with technologically-advanced trackers is a doubly effective way to make it, literally, better than ever. 

One of the most common questions about repowering is, “How long will my system be offline?”

Repowering utility-scale is possible with minimal disruption. A phased (modular) repowering strategy breaks the repowering project into segments. By targeting individual sections or subsystems a few at a time, rather than overhauling everything simultaneously, production losses are controlled and minimized. 

An experienced repowering team will often begin by replacing the most critical elements first, to optimize production while minimizing operational interruptions. They will:

• Develop comprehensive timelines

• Establish backup protocols to handle unexpected challenges

• Verify compatibility between legacy infrastructure and new equipment (to avoid integration issues and delays)

• Schedule work for off-peak periods to align with lower energy demand

• Utilize interim solutions to maintain continuous power during essential upgrades

Mature systems that aren’t operating at peak performance will continue to lose their ability to perform over time. By repowering, asset owners can nip productivity loss in the bud. And with a phased and strategic repowering approach, an aging site will experience minimal downtime as it regains its original potential. 

The solar industry has grown by over 2,000% since 2005, when the Energy Policy Act was passed. As large groups of sites age in tandem, repowering is becoming a bigger part of the industry conversation. Solar is a renewable resource, and it stands to reason that its sites should be renewable too. Repowering provides a way for asset owners to renew the value, production, and life of a site. 

Interested in how GameChange can help you repower an aging site or build a new one? Contact our team to learn more - we’d love to hear how we can help.