Solar Panel Temperature Coefficient: What To Know

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Solar Panel Temperature Coefficient: What To Know

It’s not news that solar energy is a key player in the alternative energy realm. Solar’s a powerful substitute for fossil fuels, and those who go solar can generate electricity for their homes and businesses in an astoundingly environmentally friendly way. 

However, efficiently harnessing the sun’s energy requires deeply understanding various factors. In particular, you must understand the factors that influence solar panel performance. One of those is temperature. 

So, does temperature affect solar panels? Does temperature affect solar panel efficiency?

A solar panel temperature coefficient plays a big part. It’s a crucial aspect of solar energy efficiency because it affects solar panels’ efficacy in different climates and conditions. 

Let’s take a look at the main points so you get the most out of going solar:

  • What the solar panel temperature coefficient is
  • The effect of temperature on solar panels
  • Factors that influence a solar panel temperature coefficient
  • How to optimize your panels’ efficiency

[Related: 50 Fascinating Solar Power and Solar Energy Facts]

What Is the Solar Panel Temperature Coefficient?

A solar panel temperature coefficient is a metric representing the rate at which a solar panel’s efficiency decreases as its temperature rises. With record-high temperatures these days, it’s a metric you need to know about. 

It’s an essential efficiency factor because solar panels operate most effectively when they’re under direct sunlight. However, there’s such a thing as too much direct sunlight — well, if the panels get hot enough. 

And as you’d expect, increased sunlight often leads to an increase in a panel’s temperature. As temperature rises, a solar panel’s efficiency tends to decrease because of how photovoltaic cells work.

[Related: A Beginner’s Guide to Solar Panels]

Negative Temperature Coefficient

Let’s get one thing straight before we go any further: Most solar panels have a negative temperature coefficient. 

This means that as a solar panel’s temperature rises, its efficiency decreases (they’re negatively correlated). In other words, it’s highly unlikely you’ll have (or buy) a solar panel that works better when it gets too hot. 

The negative coefficient indicates that for every degree Celsius increase in temperature, the solar panel’s efficiency drops by a certain percentage. This percentage varies by your solar panel brand and type. 

But how hot do solar panels get? The minimum temperature for solar panels to function efficiently in warm weather is generally 59 degrees Fahrenheit. 

On that note, the solar panel temperature range (i.e., the temperature range panels general function within) is 59 degrees Fahrenheit to 95 degrees Fahrenheit. (It’s the optimal temperature for solar panels, at least.) 

Do solar panels get hot? Can solar panels get too hot? They certainly can — and do. 

On that note, the operating temperature of solar panels is about 185 degrees Fahrenheit. This seems high, but solar panels operate at a much hotter temperature than the air around them. That’s because, as you’d expect, they absorb the sun’s heat and have to handle those hot daily temps! 

So while the operating temperature is 185 degrees Fahrenheit, the best temperature for solar panels (outdoor temperature, that is) is 77 degrees Fahrenheit.

Note: Freedom Solar Power provides SunPower® solar panels, which have the highest-rated efficiency on the market. They’re easily the best solar panels for high-temperature areas. 

Factors Influencing the Solar Panel Temperature Coefficient

Multiple factors influence the solar panel temperature coefficient. Let’s explore them.

Panel Technology and Design

The technology and design of your solar panels, including their structure and layout, can affect their temperature coefficient.

For example, different solar panel technologies — such as monocrystalline and polycrystalline silicon, and thin film solar cells — all have different temperature coefficients. 

Solar panels with monocrystalline and polycrystalline silicon typically have a temperature coefficient ranging from -0.44% to -0.50%. SunPower monocrystalline panels perform better, with a coefficient of -0.38%. So, in terms of getting the best temperature coefficient, solar panels from SunPower are the way to go.

However, thin-film solar panels tend to have a lower temperature coefficient than traditional monocrystalline or polycrystalline panels. Panels with thin-film solar cells have coefficients closer to -0.2% / degrees Celsius

Roofing Material

As you’d expect, your roofing material can affect your solar panels’ temperature. Why? Certain rooftops (or materials in wall-mounted or ground-mounted solar panels) can absorb heat better than others. 

In terms of roofing materials, these types are best and most common for installing solar panels:

  • Asphalt shingles
    • This type doesn’t absorb much sunlight.
  • Metal
    • This type is great at reflecting sunlight.
  • Tile
  • Tar and gravel
  • Wood (such as synthetic cedar)
    • This is a great option for a ground-mounted system or community solar farm.

In general, the lighter-color roof you have, the better. You want your roofing material to have a high solar reflectance so your roof itself remains cool and doesn’t increase your panels’ temperature. Like we noted earlier, your panels lose efficiency if they go past their ideal solar panel temperature coefficient. 

But while certain roofs can remain cooler than others, a recent study showed that solar panels can actually protect your roof and keep it cooler. This is a huge benefit to homeowners in really hot temperature regions. So if you don’t have a roof material that’s designed to reflect light and not absorb heat, don’t fret, solar panels are there to help.


Your geographic location has a huge impact on the solar panel temperature coefficient. Climate and average temperature are the primary culprits. 

If you live in a location with a hot or humid climate, like Texas or Florida, you likely deal with high average daily temperatures. As a result, your roof (or anywhere your panels are) is probably far from cool. And that means it might be too hot for solar panels.

In locations like these, it’s important to take all precautions you can to keep your panels cool. Again, your roofing material influences the solar panel temperature coefficient. But that’s not the end: Shading from trees and buildings, your system’s orientation and more details chime in, too. 

So, two main locational elements determine how the temperature coefficient affects energy production:

  • The climate 
  • The average temperature at the place of installation 

[Related: What To Know Before Installing Solar Panels]

How To Optimize Efficiency

While the temperature coefficient affects solar panel performance, it’s not the only factor at play. You can optimize your solar energy systems in other ways to produce maximum energy.

First, select high-quality solar panels with lower temperature coefficients — such as those from SunPower. Next, consider other efficiency-enhancing strategies, like proper ventilation, spacing, shading and roofing material.

[Related: 51 Uses of Solar Energy]

Contact Freedom Solar for the Most Efficient Solar Panels

Understanding every facet of solar energy generation is helpful when you want to live more sustainably. But you don’t need to be a pro — you just need to know the basics, and the solar panel temperature coefficient is one of those fundamentals. 

Although you might overlook it, the solar panel temperature coefficient is pivotal in determining how effectively your solar panels convert sunlight into electricity. 

By grasping the metric’s significance, consumers, businesses and policymakers can make informed decisions that lead to more efficient and effective solar energy use — regardless of the climate they’re in.

When purchasing SunPower solar panels from Freedom Solar, you enjoy the highest-rated efficiency on the market. So give us a call at (800) 504-2337 or complete our online inquiry form when you’re ready to start harnessing solar. One of our energy consultants will be in touch!

Featured image via Unsplash

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Willie Nelson for Freedom Solar

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