Fresno Heat and Solar Panels: Do High Temperatures Affect Efficiency?

Does Heat Affect Solar Panel Efficiency?

Yes—but not in the way most people think.

While solar panels thrive in direct sunlight, they don’t actually love high heat. Solar panels are tested under ideal conditions—specifically 77°F or 25°C. Once temperatures climb beyond that, solar cells become slightly less efficient at converting sunlight into usable electricity.

That drop in performance is measured by something called the temperature coefficient.

What Is a Temperature Coefficient?

Every solar panel has a spec called its temperature coefficient. It tells you how much the panel’s output decreases for every degree Celsius above 25°C.

For example, if a panel has a temperature coefficient of -0.3%/°C, and the panel heats up to 40°C (104°F), it would lose around 4.5% of its rated power output.

So yes, Fresno’s 100+ degree summer days will cause a slight drop in efficiency.

But that’s not the full story.

Sunlight in Fresno Offsets the Heat Loss

Here’s the good news: Fresno gets a lot of sun.

Even with the heat, you’re getting consistent sunlight from spring through fall—and even decent winter sun compared to other areas of the country. In solar production terms, Fresno averages between 1,550 and 1,850 kilowatt-hours per kilowatt installed (kWh/kWp) depending on roof angle and panel direction.

In short, the sunlight here more than makes up for the small performance dip from the heat.

So while your panels might be 5% less efficient in the middle of a heatwave, they’re still cranking out plenty of power overall. Especially if your system was designed and sized correctly from the start.

Why Panel Choice Matters in Hot Climates

Not all solar panels perform the same in the heat. At Supreme Solar and Electric, we focus on Tier 1 panels that are built for durability and high performance, even in extreme conditions.

Here are a few of the panels we trust in Fresno’s climate:

REC Alpha Pure Series

• Temperature Coefficient: -0.24% / °C
• High output in hot weather
• Long-term reliability and industry-leading warranty

Jinko Tiger Neo N-Type (TopCon Cells)

• Temperature Coefficient: -0.29% / °C
• Advanced cell tech with excellent thermal performance
• Great for high-sun regions

Q Cells Q.TRON Series

• Temperature Coefficient: -0.34% / °C
• Trusted performance in tough environments
• Strong track record across California

These panels are engineered to maintain more production when the temperature rises, which can make a significant difference during Fresno’s hottest months.

Inverter and System Design Matter Too

Panel selection is important, but how the system is installed and designed plays a huge role in long-term performance:

✔️ Ventilation Matters

We design systems to allow airflow behind the panels, helping reduce temperature buildup.

✔️ Correct Tilt and Placement

We account for summer sun angles and roof exposure to get the most efficient production all year.

✔️ Shade Mitigation

We use module-level optimization to reduce output loss from hot spots or nearby shading, especially around chimneys or trees.

When done right, your solar system will be fine-tuned to handle Fresno heat without skipping a beat.

Will It Still Offset My High Summer Bills?

Absolutely.

In Fresno, air conditioning is usually the biggest driver of electric bills, and usage spikes during the hottest months. That’s also when your solar system is generating the most power—so even with slight heat-related losses, your system can still cover a large chunk (if not all) of your usage.

With the right panel choice and design, we regularly build systems that offset 110% to 120% of a home’s annual electricity usage, even in homes with pools, EVs, or multiple AC units.

We Build Systems with Heat in Mind

At Supreme Solar and Electric, we’ve installed systems across the Central Valley for years. We know how Fresno’s heat affects performance, and we account for it in every design:

• We size your system based on realistic production modeling that includes heat loss.
• We choose high-quality panels with strong temperature coefficients.
• We include battery backup for homes that want additional grid independence.
• And we handle everything—from permits and inspections to monitoring and maintenance.

Final Takeaway: Yes, Heat Affects Efficiency—But It’s Already Accounted For

Fresno’s heat will slightly reduce the peak performance of your solar panels. But with the right equipment, smart design, and proper installation, you’ll still get excellent production year-round.

More importantly, you’ll still offset those massive PG&E bills—especially in the summer—when you need it most.

Ready to Get a System That’s Built for Fresno?

If you’re thinking about going solar but worried about how the heat might affect your investment, we’re here to help.

We’ll design a system that’s built for your home, your usage, and Fresno’s climate—with no shortcuts.

📞 Contact us for a free custom solar proposal today and let’s build a system that works, even in 110-degree weather.