Can solar panels warm their surroundings? Yes, but so can other materials

Photovoltaic solar panels function by absorbing light. Some of that light jolts electrons inside the panel, which flow out as electricity. But what about the rest? Many solar panel opponents would have you believe that much of it turns into dangerous heat.

On 17 April 2025, renewable energy opponent James Melville posted on X a claim that, “because the panels are so much darker than the surrounding vegetation, large swathes of solar panels will absorb and emit heat at higher rates, which can have unknown consequences on the surrounding environment.”

This idea is a recurring one – for example, another X post by Ashton Forbes from September 2024 garnered more than 100,000 views stating that, “Theoretically,” the heat from solar panels “could impact the weather.”

In fact, researchers have studied whether solar panels actually do this. Their results tell us that, while solar panels can warm their surroundings, singling them out for this is misleading. Many other human activities can create starker hot spots. Moreover, multiple studies tell us that, on the whole, solar panels prevent future global warming by replacing greenhouse-gas-producing fossil fuels. 

Below, we’ll describe more on what the science says about solar panels and heat.

Solar panels often absorb no more heat than asphalt or roof tiles

Claims that photovoltaic solar panels are “darker” than their surroundings allude to a measurement called albedo – the portion of incoming light that a material reflects. Albedo is measured on a scale from 0 to 1 – higher albedo means a lighter-colored surface that reflects more light. A material with an albedo of 1 is perfectly white, reflecting all the light that strikes it.

A material with an albedo of 0 is the opposite, perfectly dark and absorbing all incoming light. Because darker, lower-albedo materials absorb more light, they tend to heat up more.

Many common materials in built-up areas, such as asphalt, roof tiles, and concrete, have low albedo. This is one reason cities are warmer than their surrounding countryside – which scientists call the urban heat island effect. (As we’ll see later, this is an example of how human activities aside from solar farms can heat up your surroundings.)

Below, we compare the albedo of photovoltaic solar panels with those of a few common materials and land types (Figure 1):

You’ll see that solar panels – and land covered with solar panels – have similar albedo to other common building materials. Researchers and planners typically assume that a solar panel has an albedo of 0.1^[1]. 

In practice, we don’t usually cover an entire space with solar panels. Solar farms usually have space in between rows of solar panels. This space tends to reflect more light and increase the solar farm’s albedo. A 2024 study examined 352 solar panel sites around the world and found an average albedo of around 0.16^[1]. If the in-between space has higher albedo, so will the solar farm: a 2023 estimate placed the albedo of one solar farm in open desert sand at 0.23, similar to concrete. 

Albedo doesn’t tell the whole story – something that the claims ignore, and which we’ll explain later – but it does tell us that solar panels probably don’t create an inordinate amount of heat compared to other materials. This is one reason it’s misleading to single out solar panels for creating heat. We’ll discuss more in the next section.

(We shouldn’t confuse photovoltaic solar panels with solar water heating or concentrating solar power, which are intentionally designed to provide heat from sunlight. Photovoltaic solar panels are not.)

Scientists have studied how solar panels affect the weather

Despite the claim that solar panels “can have unknown consequences on the surrounding environment”, there’s actually plenty of scientific work on how solar panels affect their surroundings.

We know that building solar panels can decrease a parcel of land’s albedo. How much its albedo drops is dependent on the type of land underneath. Solar panels built on desert sand will decrease the local albedo more than solar panels built on grass or asphalt. Lowering a land’s albedo can lead to warming, both locally and globally – as we’ve seen, lower albedo reflects less sunlight back into space^[1,2].

But even when solar panels do have a warming effect, they can still make up for it in other ways. By adding solar panels to the grid, we can replace electricity generated by burning fossil fuels. In doing so, we are negating the global warming those fossil fuels would have caused. 

A 2024 study found that “the clean electricity generated by PV [solar panels] in most sites could offset their adverse albedo impacts within a single year” – on average, solar panels last 20 to 30 years. In other words, for the vast majority of a typical solar farm’s life, it’s doing far more to reduce future warming^[1].

What about the claim that solar panels “could impact the weather”? Scientists have in fact studied whether solar farms can increase their surrounding air temperature. There is, for example, evidence solar farms can create their own little ‘heat islands’ – a 2016 study found that solar farms built in the Arizona desert increased the air temperature by 3-4 °C (5-7 °F) at night^[3].

But it’s important to keep in mind that other human buildings can create heat islands that take up a great deal more area. Take the Arizona example – the nearby metropolis of Phoenix is regularly 4 °C (7 °F) warmer on average than its surroundings. This urban heat island encompasses much of the city, many miles or kilometers wide. Meanwhile, when researchers observed the solar farm’s heat island effect, they also observed that the heat island effect drops off within less than a few hundred feet/meters.

In fact, when we look at other factors, there is evidence that placing solar panels on rooftops in certain urban areas can actually have a cooling effect by providing shade, thus reducing the need for air conditioning. Air conditioners are one factor that makes cities hotter. Consequently, solar panels may actually cool off an urban heat island^[4]. This is one example of how albedo doesn’t tell the entire story.

Researchers who conduct this kind of work do not believe that these effects are reasons to avoid building solar panels. Instead, they believe we should focus on building solar panels in ways that reduce their impacts on the environment. For example, this is one disadvantage of building large solar farms in the desert – doing so changes the albedo more than building them in grass or on rooftops^[1,2].

It’s also important to keep in mind that a key reason solar panel supporters want to build them is to replace electricity from fossil fuels. The whole world has warmed about 1.4°C (2.5°F) on average since 1900 primarily because of greenhouse gases from burning fossil fuels^[5]. As we’ve seen, this warming is far more severe and far more dangerous than any known effect of building solar panels^[1,5].

Solar panels can benefit nearby life

If solar panels absorbed heat in a way that really was destructive to its environment, we might expect that solar panels are damaging to life in the surrounding area. Scientists have studied this as well, and they’ve found that this often isn’t the case.

A 2025 study surveyed more than 50,000 solar farms around the world and found that 52% of them actually increased the vegetation around them^[£]. As a 2024 review paper points out, various studies have shown that solar panels boost the yield of certain crops, like potatoes and peppers, and cut the water needs of other crops, such as lettuce^[₭]. In many cases, this is because the solar panels provide valuable shade that keeps plants in better health.

It’s partly for this reason that there’s a lot of interest in placing solar panels on farmland. This is known as agrivoltaics. As we’ve detailed in a past article, it can come in a few different forms – growing crops in the open space between panels, allowing animals to graze around panels, and building greenhouses with panels on their roofs, to name three (Figure 2). This sort of coexistence wouldn’t be possible if solar panels ravaged their surroundings with heat.

It’s easy to make alarming claims about new technology whose inner workings aren’t obvious. Solar panels are no exception. We’ve seen claims that solar panels contain toxic chemicals, that they’re more emissions-intensive than they seem, or that they’ll create mountains of waste. The claim that solar panels heat their surroundings is just another amongst them.

When you encounter claims like this, it’s useful to think about context. While it is true that solar panels can have an effect on their surroundings, plenty of other human activities can do the very same – including, and especially, the burning of fossil fuels. So, when you see a claim like this, it’s good to ask if it is cherry-picking the effects of solar panels.

References:

• 1 – Wei et al. (2024) Small reduction in land surface albedo due to solar panel expansion worldwide. Communications Earth & Environment.
• 2 – Xu et al. (2024) A global assessment of the effects of solar farms on albedo, vegetation, and land surface temperature using remote sensing. Solar Energy.
• 3 – Barron-Gafford et al. (2016) The Photovoltaic Heat Island Effect: Larger solar power plants increase local temperatures. Scientific Reports.
• 4 – Masson et al. (2014) Solar panels reduce both global warming and urban heat island. Frontiers in Environmental Science.
• 5 – Xie and Wong (2021) Potential benefit of photovoltaic pavement for mitigation of urban heat island effect. Applied Thermal Engineering.
• 6 – IPCC. (2022) Climate Change 2022: Impacts, Adaptation and Vulnerability.
• 7 – Wu et al. (2025) Diverse vegetation responses to solar farm installation are also driven by climate change. Communications Earth & Environment.
• 8 – Widmer et al. (2024) Agrivoltaics, a promising new tool for electricity and food production: A systematic review. Renewable and Sustainable Energy Reviews.