A wave of U.S. solar is hitting the age when inverters fail, often with no exit plan. Why decommissioning is the wrong default and repowering is the fix.
The first big wave of U.S. solar is getting old. Systems installed in the late 2000s and 2010s on rooftops, landfills, and open land across the Northeast and beyond are reaching the point where major components need replacing.
Most of those systems were built without a plan for what happens next. There's often no exit strategy, only rising liability and risk.
Here is how much U.S. solar is aging, why decommissioning is the wrong default, and why repowering is the bigger opportunity.
How Much U.S. Solar Is Reaching the End of Its Original Life?
Some 23 GW of U.S. solar across residential, commercial, and utility-scale projects is approaching the 15-year mark, according to Wood Mackenzie analysts quoted by Utility Dive. That's when first- and second-generation inverters typically reach the end of their average lifespan.
Wood Mackenzie also estimated that an average of 4.5 GW of solar projects a year would need new inverters. In some years, that's close to half the capacity the U.S. installed.
The panels themselves often last much longer. Wood Mackenzie's research head noted that most panels in older installations "continue to produce nearly as much energy as when they were first installed." It's the equipment around them that wears out first.
Why Don't Aging Solar Projects Have an Exit Plan?
Most early solar projects were financed and built to deliver power, not to manage the end of their life, so few have clear plans for replacement, repowering, or removal. The original developer, installer, or lender is often long gone.
That leaves owners with systems nobody fully understands. Common gaps include:
- ●Unclear responsibility. No one knows who owns maintenance or decisions anymore.
- ●Lost monitoring. Old data platforms stop working or become inaccessible.
- ●Obsolete parts. Replacement equipment for older inverters is hard to find.
- ●No budget. Few projects set aside money for major repairs or removal.
We've seen nobody knowing who's responsible for the system become one of the most common problems commercial owners face.
Is This Only a U.S. Problem?
No. Countries that adopted renewables early are facing the same question, and industry groups are starting to push for a plan.
In Australia, a July 2025 RenewEconomy report covered a new RE-Alliance toolkit on retiring renewables. It noted that 12.5 GW of Australian renewables is expected to approach retirement by 2045.
The report pointed to repowering as a major opportunity. A 2024 GHD study found 1.7 GW of retiring Australian wind projects could be repowered to supply 6 GW using one-third fewer turbines.
Europe faces a similar wave. About 86 GW of European wind capacity will be over 20 years old by 2030.
Why Is Decommissioning the Wrong Default?
Decommissioning removes working generation from the grid, creates waste, and writes off infrastructure that could keep producing with the right upgrades.
Removing an aging solar system means tearing out panels, inverters, wiring, and racking. Some of it can be recycled, but much of today's equipment was never designed with disposal in mind.
It also leaves a gap. Every decommissioned megawatt has to be replaced with new generation, which means new land, new permits, and a place in a long interconnection queue.
Some states are starting to require end-of-life planning. Pennsylvania's solar decommissioning law now requires plans and financial assurance for larger projects.
When people supported clean energy, they weren't signing up for abandoned panels. They were investing in something that lasts.
What Makes Repowering the Bigger Opportunity?
Repowering keeps an existing solar site producing by replacing failed or outdated components while reusing the land, permits, and grid connection that are already in place.
The advantages over building new or tearing down:
- ●Less waste. Panels that still work stay in service, and only failed parts are replaced.
- ●Fewer permitting hurdles. The site already exists and is already connected.
- ●Faster results. No new interconnection queue or land search.
- ●More value. Restored output brings back revenue the system has been losing.
The inverter replacement wave is also making repowering easier. Inverter manufacturers are simplifying the process as more systems from the 2010s reach that point.
How Can You Tell a Solar System Is Ready for Repowering?
A system is usually ready for repowering when production has dropped noticeably, the inverter is near or past 15 years old, or repairs keep coming back. Those signs tend to show up together.
Warning signs to watch for:
- ●Falling output. Production well below the system's original expectations.
- ●Inverter age or faults. Frequent error codes, shutdowns, or units near the end of their lifespan.
- ●Obsolete equipment. Replacement parts that are discontinued or hard to source.
- ●Lost monitoring. No reliable data on what the system is actually producing.
- ●Rising repair bills. Service calls that fix symptoms without solving the problem.
What Should Owners of Aging Solar Do?
Owners should assess their system's condition, confirm who is responsible for it, and decide whether to keep, repower, or sell before a major failure forces the decision.
At Do Good Energy, we acquire aging and underperforming solar systems. We replace broken components, redesign outdated arrays, and turn stalled projects back into productive infrastructure.
How the industry handles this next chapter will shape public trust in renewable energy. Walking away from aging systems sends the wrong message. Building on what's already in the ground sends the right one.
For more on the process, see what solar repowering involves.
Start With a Ballpark Estimate
If you own an aging solar system and don't have a plan for it, start with numbers. Find out what your existing solar project may be worth before deciding whether to repair, repower, or sell.
Sources: Utility Dive, "US solar farms are aging. Is it time to begin repowering?"; RenewEconomy, "Deep dive into decommissioning"
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