Repowering: A smarter path for aging renewable infrastructure

As the U.S. solar fleet continues to mature, a significant wave of reinvestment is approaching, one that will shape not just individual assets, but portfolio performance and grid reliability for decades to come. Over the next five years, more than 23 GW of solar capacity will require electrical upgrades, placing increased pressure on owners, developers, O&M contractors to make informed lifecycle decisions. When managing existing renewable energy assets, owners typically face three choices: rebuild the infrastructure, repower it, or retire it altogether.

Rebuild, repower, or retire

In practice, repowering often makes the most sense both financially and operationally. This approach involves updating, refurbishing, or replacing selected components with newer, more efficient technology. The main goal is to extend the lifespan of the asset, boost reliability and energy production, and make the most of the current site’s established factors like land use, permits, and grid connections.

Reasons to repower

There are many reasons why repowering is often the best solution over full rebuilds, including:

Economics: When factoring in permits, land, and grid interconnections, updating existing installations can be 40-70% more cost-effective than building from scratch.

Speed: With one-third of U.S. solar farms nearing the end of their lifespan, time is of the essence. Modernization and repowering can reduce downtime versus full replacement pathways, meaning owners can continue service quickly and cost-effectively.

Rejuvenation: Repowered infrastructure can last approximately 20+ years, making it equivalent to the lifespan of a brand-new solar farm, without the cost, downtime, and disruption of total replacement.

Continued Interconnection: Repowering often preserves existing interconnection rights, which are usually the most constrained and valuable element of a renewable project. In today’s congested queue environment, maintaining grid access can be decisive in sustaining long-term operability.

How the job gets done

So, you want to repower your solar farm, but where do you start? The first step is to assess whether repowering is technically and economically justified. Field assessments are ideal to determine if the existing solar feeder cables are operating properly. The assessment analyzes the current infrastructure and health of the cable system through various diagnostic tests, such as partial discharge (PD) testing, sheath testing, withstand testing, and neutral corrosion assessment, to determine if and how the owner can repower the solar farm.

PD testing is a diagnostic test that identifies cable defects while the cable is in service, helping prevent unplanned outages. As part of the field assessment, it helps determine whether issues can be mitigated before a full replacement is necessary. PD testing serves as a key indicator of whether existing cables are suitable candidates for rejuvenation.

Cable rejuvenation goes hand-in-hand with repowering, as they both have the same premise: updating and reviving what’s currently there instead of replacing it. If the PD testing determines that a cable can undergo the cable rejuvenation process, a silicone fluid is injected into the conductor strands of the cable. The fluid then migrates (diffuses) through the conductor shield and permeates the insulation (PE or EPR), displacing any moisture trapped in the cable and repairing the insulation’s chemical structure. The full process takes approximately 90 minutes per segment, ensuring site disruption and downtime are minimal.

After rejuvenation, the cable’s dielectric strength increases, extending the reliable life of the cable by up to 40+ years and postponing the need for replacement by many decades. The cable rejuvenation process also restores the cable to a better-than-new condition at roughly one-third the cost of cable replacement, making it an ideal solution for owners looking to repower their current farm.

Field assessment services and cable rejuvenation are just some of the options owners can explore when looking to repower their farms. These strategies help mitigate operational risk, ensure compliance, reduce long term O&M costs, and improve overall system reliability. Most importantly, they provide confidence that aging infrastructure can continue to operate safely and effectively for years to come.

Repowering is increasingly essential to maintaining momentum across the renewable energy sector. Rather than defaulting to costly new builds, reinvesting in existing renewable assets preserves infrastructure, strengthens grid reliability, improves grid efficiency, and helps owners navigate real-world constraints like limited land, interconnection capacity, and tight project timelines.

When it’s time to repower, owners should partner with teams who bring deep expertise in cable systems, diagnostics, and on-site evaluation. The right expertise ensures modernization decisions that are technically sound, economical, reliable, and built for long-term sustainability.

Clyde Melton is the Director of Renewable Energy at Southwire Company where he leads the charge in expanding the company’s footprint in the utility-scale wind, solar, and battery energy storage systems. With over 14 years of experience in the wire and cable sector, Clyde brings a wealth of expertise in driving business growth and providing value that meets the evolving needs of clients and stakeholders.

The views and opinions expressed in this article are the author’s own, and do not necessarily reflect those held by pv magazine.

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