How Do Climate and Aging Affect U.S. Solar Panels? NREL Investigates

olar power, a frontline hero in our fight against climate change, faces its own battles with time and nature. The National Renewable Energy Laboratory (NREL) has recently shed light on this with a detailed four-year study, providing an unprecedented look at how time and extreme weather are reshaping America's solar game.

Understanding Solar Panel Aging

Photovoltaic (PV) systems, designed to harness solar power over decades, aren't immune to the effects of time and nature. Even small losses in energy production can have a big impact over the long haul, significantly affecting profitability.

The NREL team has gathered a massive data set from 25,000 inverters across nearly 2,500 PV sites in 37 states and territories. Their findings show an average performance decline of 0.75% annually, consistent with earlier, smaller studies. Interestingly, solar panels in hotter areas tend to degrade faster—almost twice as fast as those in cooler regions.

Chris Deline, a group manager at NREL, reflected on the results, noting, "First, it shows that our fleet of PV systems, on the whole, is not failing catastrophically, but rather degrading at a modest rate within expectations. It's important that we quantify this rate as accurately as we can, because this small but tangible number is used in almost all financing agreements that fund solar projects and provides critical guidance for the industry."

Facing Nature's Fury: The Role of Extreme Weather

Extreme weather—be it hurricanes, hailstorms, or floods—poses a real threat to solar systems. However, the extent of its impact has been somewhat unclear. The NREL researchers took a deep dive into this issue by linking solar performance data with extreme weather events tracked by the National Oceanic and Atmospheric Administration (NOAA). Their discovery? Most solar systems bounce back quickly from weather-related interruptions, typically within two to four days, resulting in a mere 1% dip in yearly performance.

Yet, in cases of severe weather like large hail or strong winds, the long-term effects on solar performance were notably higher. PV systems subjected to extreme weather conditions, such as hail larger than 25 millimeters in diameter or winds exceeding 90 kilometers per hour experienced faster degradation.

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Bracing for the Storm: Enhancing Solar Power Resilience

The NREL's findings aren't just a warning; they provide a guide for improvement. The study suggests adopting more realistic stress tests and standardizing high-quality installation practices to boost solar system resilience. The overarching message is clear: with the right mix of rigorous testing, skilled installation, and proactive maintenance, the U.S. solar fleet is well-equipped to face any challenge, ensuring a sustainable future remains within our reach.

As solar technology advances, electricity increasingly relies on solar power, driving a shift towards renewable energy for a cleaner, more sustainable future.

Sources:

https://www.nrel.gov/news/program/2024/