As the solar industry continues to expand, conversations often center on innovation — smarter inverters, higher-efficiency modules, and advanced storage integration. Yet, for many solar farm operators and maintenance professionals, the challenge isn’t about the newest technology. It’s about keeping the systems they already have running.
Across thousands of installations worldwide, aging inverters are quietly becoming one of the biggest risks to long-term solar reliability. These units depend on power semiconductor components — particularly IGBTs (Insulated Gate Bipolar Transistors) and thyristors — that are increasingly difficult to find as manufacturers discontinue legacy product lines. When those parts fail, the entire system can grind to a halt.
The Growing Challenge of Inverter Reliability
Solar inverters are the heart of any photovoltaic system. They convert DC electricity from panels into AC power suitable for the grid. But like all electronics, inverters have finite lifespans — and their failure rates rise significantly over time.
According to data from the National Renewable Energy Laboratory (NREL), the average system availability for large solar arrays remains high, around 97–98%, but even a few percentage points of downtime can translate into major revenue loss for utility-scale operations. Other studies have shown that inverters account for up to 60% of total failures within solar power plants, and that downtime from these failures can lead to production losses as high as 30% in extreme cases.
Field data also paints a clear picture of aging risk. A European survey of residential and small commercial systems revealed that by year fifteen, roughly one in three inverters had experienced a major failure. For utility-scale sites — many of which were built between 2010 and 2015 — that timeline is catching up fast.
The Cost of Downtime and the Burden of Replacement
When an inverter fails, production stops immediately. Every day of downtime represents lost power generation, potential penalties in power purchase agreements, and sometimes reputational damage for operators managing multiple assets.
Replacing a failed inverter isn’t always simple. Newer inverter models often use different architectures, communication interfaces, or voltage tolerances. Retrofitting can require redesigning the installation, re-certifying electrical systems, or even modifying balance-of-system components — all of which adds cost and time.
It’s not uncommon for full inverter replacements to reach five-figure costs per unit, especially in commercial or utility settings. By contrast, repairing an inverter with the right replacement power module — even one that’s considered obsolete — can restore performance for a fraction of the price and extend the unit’s lifespan by several years.
Why Obsolete IGBTs Still Power the Solar Industry
Despite the emergence of newer semiconductor materials such as silicon carbide (SiC) and gallium nitride (GaN), the vast majority of installed solar inverters still rely on traditional IGBT technology. These devices remain the workhorses of high-voltage switching — rugged, efficient, and proven in decades of field service.
However, as semiconductor manufacturers phase out older product lines, many inverter models built in the 2000s and early 2010s are now supported by components that are no longer in production. When an IGBT or thyristor fails in these systems, maintenance teams often face an impossible choice: replace the entire inverter, or search for an obsolete part that may only exist in limited quantities.
This is where expertise in legacy component sourcing becomes essential. Understanding part cross-references, verifying authenticity, and ensuring the electrical characteristics match the original design can mean the difference between a smooth repair and an expensive failure.
Extending Inverter Life Through Proactive Maintenance
Preventing failures begins with monitoring and data. Operators should pay attention to inverter temperature trends, switching frequency changes, and subtle signs of degradation in performance. Many studies have shown that thermal cycling is one of the most common stressors leading to semiconductor wear-out. Improving ventilation, maintaining stable load conditions, and avoiding overheating during peak production hours can all extend component life.
Another effective strategy is parts forecasting. Asset managers should maintain a record of which IGBT or thyristor models are used in each inverter series, then verify whether those parts are still being produced. If not, planning ahead by securing spares or validated replacements can significantly reduce downtime risk. This proactive approach also helps prevent the “panic purchasing” that occurs when a system fails and sourcing becomes urgent.
Repair, Don’t Replace: A Smarter Path to Sustainability
Repairing existing equipment isn’t just good economics — it’s good sustainability practice. The environmental footprint of producing new inverters, shipping them globally, and decommissioning older units adds up quickly. Extending system life by even five to ten years through component-level repairs can reduce waste, conserve materials, and improve the overall carbon return on investment for a solar installation.
From an asset management standpoint, preserving operational equipment supports consistent power generation and predictable revenue streams. Investors and insurers increasingly recognize the value of maintenance strategies that reduce the likelihood of large-scale replacements.
Looking Ahead: A Growing Legacy Fleet
Globally, more than half of the world’s solar capacity was installed before 2018. That means millions of inverters are now entering their second decade of operation — right when age-related component failures typically increase. The “legacy inverter” era has arrived, and with it, a growing demand for technical expertise in sourcing and integrating obsolete components.
Ensuring the continuity of solar production depends not only on innovation but on stewardship — taking care of the infrastructure already in place. Reliable sourcing, maintenance, and engineering support for existing systems are key parts of that responsibility.
Keeping the Power Flowing
Solar technology has always been about longevity — systems designed to produce clean energy for decades. Yet the key to that promise lies not only in innovation, but in maintenance, foresight, and the ability to adapt as components age and supply chains change.
Sourcing reliable, high-quality legacy components is a practical way to extend the life of solar systems already delivering value. When older IGBTs, thyristors, or other power modules reach end of life, finding the right replacement ensures those systems continue performing at their best — safely, efficiently, and sustainably.
For operators and engineers committed to keeping existing assets running, experienced suppliers who understand the nuances of obsolete semiconductors can make all the difference. ATI Accurate Technology has built their reputation on helping the industry bridge that gap — keeping proven systems in service and ensuring the solar energy that was promised keeps flowing for years to come. Shop parts HERE