Recently, I’ve noticed a number of solar myths coming back to haunt the comments section of this blog. Here’s the latest one:
“Those black solar panels actually heat the planet by increasing the amount of energy the earth absorbs from the sun? Ha! You never thought of that did you!”
Solar panels absorb energy. It’s what they’re made to do. As a result, they often reflect less sunlight energy back into space than the surface they’re placed over.
So no, solar panels do not heat the Earth.
The overall effect of solar panels is far in the opposite direction. They help prevent a heating planet by reducing fossil fuel generation and greenhouse gas emissions.
This may then cause someone to ask…
“Ignoring the effect of greenhouse gases, do solar panels heat the planet?”
The answer is still no. This is because unlike most other forms of generation, solar doesn’t release large amounts of waste heat in the process of producing electricity. By reducing the need for generation that creates heat from chemical or nuclear reactions, solar power helps cool the planet.
After learning this, someone who is really determined to know if solar panels contribute to global heating in any way could ask…
“Ignoring greenhouse gases and ignoring waste heat unavoidably released by most other forms of generation, do solar panels heat the planet?”
In that case, the answer is…
…maybe.
It depends on the location and situation, but overall solar panels have a mild cooling effect on the planet. While the cooling effect isn’t strong, it is better than any other form of generation.
Below, I’ll explain why solar is the coolest energy source.
Albedo
Albedo is a measure of how bright or dark something is1. An object that most sunlight energy bounces off has a high albedo, while something that mostly absorbs sunlight has a low albedo.
“Hi! My name’s Al Bedo and you can bite my shiny mirrored butt!” (Because I lost a bet I’m required to reference a bizarre 70s science fiction movie in this article. Anyone who can correctly name it in the comments wins my condolences.)
A perfectly reflective object will have an albedo of 1. A perfectly dark object will have an albedo of 0.
One thing to keep in mind about albedo is the world is not as bright and shiny a place as most people think. As an example, what do you think is the albedo of your bathroom mirror?
- (a) 0.99
- (b) 0.95
- (c) 0.90
- (d) 0.85
Wrong! It’s only around 0.75.
You may think using a trick question was unfair. But in my defence, I did just warn you the world is not a bright and shiny place.
As a further example, what do you think the albedo of the moon is?
- (a) 0.9
- (b) 0.8
- (c) 0.5
- (d) 0.4
Wrong! It’s around 0.14. This is because its surface is mostly dark basalt. The moon only looks bright and shiny to us because our meagre human eyes are comparing it to the dark immensity of the universe — the only thing with an albedo of 0.
Who’d have thought the moon would turn out to be so goth? IMAGE NASA (duh.)
Okay, one more. What’s the albedo of Venus, the brightest planet visible in the night sky?
- (a) 0.7
- (b) 0.6
- (c) 0.5
- (d) 0.2
The answer is (a). Around 0.7. It’s not a trick question this time because, while the world isn’t as bright and shiny as you may think, it’s not that bad a place.
Common Albedos
The approximate albedos of the surfaces that solar farms may be built over are:
- Green grass 0.15
- Australian grass (not green) 0.2
- Sand 0.4
- Soil 0.28
- Water 0.08 (Floating solar is a thing.)
Roofs come in a range of materials and colours, so their albedos cover a wide range. A dark black roof can have an albedo of 0.04 while a white roof designed to reflect heat can have an albedo of 0.77. That’s roughly on par with your bathroom mirror.
Solar Panel Albedo
The albedo of a solar panel is around 0.1. This means it absorbs roughly 90% of sunlight energy falling on it. Solar PV can only be made from certain materials, so that’s about as dark as they get at the moment. This makes them a lower albedo than most surfaces they cover, but not all the sunlight energy absorbed by a panel is converted into heat.
Solar Panel Efficiency
These days, solar panels are around 20% efficient at turning sunlight into electrical energy. This means if 10% of sunlight energy is reflected and 20% is used to power our appliances, there’s only 70% left to end up as heat. This is normally less than if sunlight hits grass or bare soil, as their albedos generally range from 0.1 to 0.3. Dry sand will reflect more heat back into space, but that’s not a good surface to build a solar farm on.
The electrical energy solar panels provide will, almost entirely, end up as heat. But this is true for electricity from any source, so is only a consideration if we’re going to do without electricity.
Snow Is White(ish)
For a solar farm to contribute to heating the earth, it generally has to be built where there is snow cover for an extended part of the year. Freshly fallen clean snow can have an albedo of more than 0.8, but it can drop to half that when it gets dirty. If a solar farm is built on what would otherwise be green grass with an albedo of 0.15, and we assume the average albedo of snow is 0.65, snow cover would have to last over 3 months before the solar panels result in overall heating.
This calculation can be complicated by the fact shade from solar panels can cause snow cover to last longer than it otherwise would, and so increase the amount of cooling they provide. On the other hand, spring rain running off solar panels may help wash snow away faster, so the effect of solar panels on snow is probably site dependent.
What About Roofs?
If you put solar panels on a roof with an albedo higher than around 0.3, it may result in more direct heating from the sun than if the roof had been left bare. But on average, the world’s roofs are pretty dark. Average roof albedo in the US may be close to 0.15, while in hot and sunny California it’s around 0.2. Australia should be better than that, but don’t get me started on Perth:
What the hell are you doing with your roofs, Perth? Do you even realize you are the second hottest state capital? Orange is not the new black, and black is worse!
But even when installed on lighter-coloured roofs, solar panels can still indirectly contribute to cooling by reducing the need for air conditioning. Because this avoids some energy use entirely, it reduces the amount of heat that results from energy generation and consumption2. In colder climates, the need for extra heating can outweigh the energy savings from reduced air conditioning, but only a small portion of the world’s population lives in these locations. It’s also an unfortunate fact that the portion of the world that counts as having a colder climate is decreasing.
As an example, this study says Paris — which is colder than Christchurch — will experience overall cooling from rooftop solar.
Albedo Isn’t Everything
So far, I’ve made it seem as if albedo is everything. But there’s more to it than that. How objects radiate heat also has an effect. While it may seem paradoxical, the fact solar panels get hot during the day can contribute to the overall cooling they cause.
Besides albedo, there are two reasons why solar panels tend to get hotter than bare roofs or open ground:
- Solar panels are mounted on frames or rails with an air gap under them, so they only transmit a limited amount of heat to the ground or roof below.
- Evaporating water can cool plants and soil but because solar panels are completely incapable of sweating they don’t have this advantage.
It’s common for solar panels to be around 20 degrees hotter than air temperature for a large part of the day. If solar panels get hotter than the area they are built over would without them, they’ll emit slightly more heat in the form of infrared radiation. This will slightly increase the amount that heads towards space and escapes the earth. It will have to fight its way past some greenhouse gases but hopefully, we’ll soon stop making it harder for infrared heat to escape the planet.
The cooling effect this causes is not large, but every little bit helps.
Waste Heat
Solar PV is the only form of electricity generation with a significant overall cooling effect. Most others directly release large amounts of waste heat into the environment. Energy sources that do this are:
- Fossil Fuels: Burning fossil fuels takes chemical energy trapped under the ground millions of years ago and releases it now. In Australia, every kilowatt-hour of electricity generated from fossil fuels results in the release of around two kilowatt-hours of waste heat.
- Nuclear Power: This creates heat by busting fat atoms from the hearts of exploded stars that got mixed into earth’s material when it was formed billions of years ago. On average, it releases more heat per kilowatt-hour of electricity generated than fossil fuels because of the challenges of dealing with radiation3.
- Geothermal Energy: This brings underground heat to the surface. This will reduce the amount of ground heat that reaches the surface, but slightly less warm ground will take thousands of years to match the waste heat emitted by geothermal power.
Three forms of generation that don’t directly contribute to world warming are:
- Hydroelectricity: Because the gravitational potential energy in water would be converted into heat anyway, hydro generation doesn’t directly cause additional heating. But since water has a low albedo, creating dams will have a very slight warming effect.
- Biomass: Burning plant material releases chemical energy and those chemicals got all energied up from sunlight. Since this energy would normally be released over a relatively short period of time, biomass doesn’t directly warm the planet.
- Wind Power: The energy in wind ends up as heat anyway, so wind turbines don’t contribute to heating. Because they are white and have nacelle cooling radiators located high above the ground, wind turbines should have a slight cooling effect. But this won’t be significant compared to solar power.
Vast amounts of waste heat are created by burning fossil fuels and breaking big atoms into angry smaller ones, but it’s not too difficult to solve this problem. All we have to do is close down fossil fuel power stations, scrap internal combustion engines, and allow the uncompetitive nuclear power industry to go out of business. This process is underway, although I think we should pick up the pace for fossil fuels.
The extra greenhouse gases we’ve added to the atmosphere cause a much larger and longer-lasting problem. They currently warm the planet roughly 20 times more than nuclear and fossil fuel waste heat and — unless we take action to reduce their concentration — they will still be making the earth warmer than it otherwise would be 10,000 years from now.
Greenhouse Gases — The Elephant In The Atmosphere
The main reason solar power is the coolest energy source is that it reduces fossil fuel greenhouse gas emissions. The carbon dioxide and other greenhouse gases we’ve added to the atmosphere have warmed the earth by over a degree and they’ll be happy to raise it by another one if we don’t stop emitting so much.
Producing electricity from solar emits zero greenhouse gases, but emissions are an unavoidable part of fossil fuel generation. In Australia, including emissions from mining, coal generation emits roughly 1kg of CO2 per kilowatt-hour generated. That’s infinity times more than solar PV.
Producing solar panels and associated hardware currently results in some emissions, but these are avoidable and will decline as we reduce fossil fuel use. They are also trivial compared to the unavoidable direct emissions from burning fossil fuels.
Solar Is The Coolest Source Of Energy
Solar is the only source of generation that has an overall cooling effect. While not large, it will improve as average solar panel efficiency gradually increases. It would also be possible to design modules to reflect more of the sunlight energy they don’t require. Making them with high albedo white frames is one simple way to do this.
The world is in a race against time to reduce greenhouse gas emissions, and wind and solar power are the two most effective tools we have to achieve this. In the future, most of our energy will come from solar as its cost is falling faster.
So don’t be distracted by ever-more desperate arguments against solar power. Solar is not heating the planet. Solar is cool.
Footnotes
- There is more than one way to measure albedo. I’m using reflection of all electromagnetic radiation, including infrared and ultraviolet, rather than just visible light. ↩
- Air conditioners don’t eliminate heat, they just move it from inside to outside, and the energy they consume doing this ends up as additional heat. ↩
- While blasting radioactive steam directly into a turbine may sound awesome, you’ll soon change your mind — or it will change by itself. Potentially into a kind of hideous mutant slug. ↩
About Ronald Brakels
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I think that’s from Logan’s Run – The Ice Robot?
Fender in Futarama says “Bite my shiny metal @$$” quite a few times too…..
You win! Have a big helping of my condolences.
His name was “Box”.
“Fish and plankton and protein from the sea. Fresh as harvest day!”
Very good!
And at the end of the day solar power is nuclear power, with the reactor millions of kms away, out of harm’s way. The only affordable and safe way to do nuclear power.
One of your best articles in a while Ronald, and covers one of my pet hates along the way: dark roof colours.
We have six neighbours in our 1970 built house, as we live at the end of a culdesac. A year or two ago, two neighbours had very light coloured roof material.
Now, none do. Why?
Because the two houses with white roofs were bulldozed, and replaced with massive brick boxes, one with a BLACK roof, and one charcoal (dark) grey. So now, no matter how good their roof insulation is, we cop the heat from those roofs depending on which way the wind blows. (It’s commonly called “heat island” effect I believe.)
When we replaced our tired 1970 tile roof eleven years ago, we switched to “surf mist” (white) colourbond, and added a thermal blanket under the new roof.
The result was an absolutely massive cooling effect and it reduced our need for aircon here in SEQ by about 95%. Now our neighbours are doing everything possible to make our long hot summer here in Qld even worse.
Why are councils allowing these dark roof colours? It’s madness.
I think it’s a bit more complicated. Material also has an impact. For example a dark concrete tile will have different heat absorbing properties to colourbond. Plus if you (like me) live in one of the coldest parts of Australia and rarely need air conditioning in the summer, on energy balance terms I think a darker roof may actually be better for you, because you absorb more heat in the winter.
My recollection is that colourbond “Surf Mist” was unavailable here, but their “Whitehaven” has an albedo of 0.77. OK, putting PV over my 40 degree northern skillion chops direct reflection spaceward. I first thought that the 20 degree higher temperature and the much higher black body radiation would greatly compensate, but visible and UV reflection would bypass the GHGs, while the (enhanced) emissions of the panels is all in the blanketted IR spectrum. Downward IR emissions are reduced by the white panel rear, a poor blackbody radiator, if I grok this stuff to any degree. And 77% of that is reflected anyway. (People with black roofs ought to be given a big pot of white paint, a big brush, and a loaned ladder, I figure.)
The 0.77 roof albedo, a roof blanket, ceiling insulation, and double glazing make the new build up to 10 degrees cooler than the old uninsulated house on a 40 degree day, with no aircon yet installed. The porch overhang was also calculated to shade the northern windows from next month.
I think the 2 sq km of native forest on the property pull enough CO2 out of the atmosphere to make up for any reduced heat loss to space of 13 kW of panels.
I also read recently that solar panels placed in sheep fields actually tend to lead to increased yield of wool and meat because of the shelter they offer to animals from heat and cold. And some feed will still grow underneath them, just not so much as out in the open areas.
I’m from Perth.
Given you mention Perth’s orange coloured home roofs, here’s my return of serve.
Instead of “busting fat atoms” a scientifically skilled author would write “splitting atoms”.
Strange. Leo Szilard, co-holder — along with Fermi — of the patent on the nuclear reactor, was always going on about busting fat atoms. For almost a year, every time he put on his pants he’d say “Törjünk szét néhány zsíratomot!” which literally translates as “Let’s bust some fat atoms.”
I apologise. Your knowledge of the hisory of nuclear power is impressive.
Thank you. My imagination is also impressive.
come on guys – everyone knows that the atom was originally split by young Einstein, the son of a Tasmanian Apple grower. They made a documentary in 1998 starring Yahoo Serious in the main role.
It doesn’t really matter – the heat we produce as humans is inconsequential. More energy hits the earth from the Sun in 1 hour than we generate in a whole year.
So no, solar panels do not heat the planet and neither does any of the energy generation that we do directly. It’s not letting that energy from the Sun back out into space with a blanket of CO2 that’s warming the planet. (I’m talking about convective heat – not reflective – CO2 doesn’t affect that but of course smog and cloud cover do.)
Maybe ‘dark’ ‘ roof is not so bad compared to other alternatives
After all, there is a 1994 film called ‘The Shadow” in which…
” The Shadow (Alec Baldwin) battles his nemesis, Shiwan Khan (John Lone), who is building an atomic bomb.”
see: https://www.imdb.com/title/tt0111143/
Measurements taken mid afternoon:
New solar panels 47.9
Weathered dark red steel roof 48.5
Grass 34.8
Appears measured temperatures don’t agree with the article.
Going by those temperatures I’d say you are most likely to be in the vicinity of Brisbane.
What part of the article are you referring to?
Grass is likely producing evaporative cooling from the leaves, so not the best way to compare actual retained versus reflected energy.
The article misses the reality that pretty much all the energy produced by solar power ends up as heat. The exception once again being anything that is lit that escapes into space.
Even when you are running a car with solar you are energising the environment – which is effectively heat. The wind from the car’s drag, the heat from the brakes, the heat from the battery and motors. It all needs to add up to zero (energy in and out). Any potential energy by lifting the vehicle will eventually be returned as heat when the vehicle returns to the original level.
So the article is actually quite wrong, the albedo of a solar panel is much worse than that of the earth’s surface so it does actually warm up the planet if thought of in isolation.
Now you have to consider the difference in albedo between Earth (~.3) and the panel .1, so 20% more gross solar energy would be absorbed by the planet (and eventually converted to heat by a solar panel and its users).
The main difference is what that energy replaces – in most cases it replaces fossil fuels which have much less than 40% efficiency. So each kW of solar energy (22% efficient) looks to be adding a little less than 1kW of extra heating (20% gross from above), where as every kW of fossil fuel energy directly produces a minimum of 1.5kW and likely 2kW of direct heat.
Add to this the ongoing heat retention of the CO2 in the atmosphere and you can see that solar panels replacing fossil fuels reduce net heat in the atmosphere even if by themselves (disconnected and not serving any generation purpose) they would increase gross energy absorption.
In Cairns
The article claims solar panels do not increase temperature, yet measurements show that if replacing grass, the local temperature will be significantly higher than it would otherwise be.
It is true that some of the solar energy is turned into electricity and hence doesn’t heat anything, but the increased temperature of a solar farm compared to the grass it covers should alter the local climate giving a heat island effect similar to a city.
Note my measurements showed that it didn’t heat up any more than the roof was doing anyway so rooftop solar should cause no change and I can only think is beneficial with no temperature side effects.
Environmental effect when panels need disposal and the original manufacturing processes are a different matter.
“It is true that some of the solar energy is turned into electricity and hence doesn’t heat anything” assumes the electricity does heat the planet which is very unlikely because certainly transmission losses to a home, heating a kettle of water, cooking are examples of electricity use which heats the planet. I don’t find the article convincing. My lay person’s understanding of solar radiation to our planet is it either ends up heating the planet, in carbon capture (stored in vegetation) or radiated from our planet into outer space. I think destroying vegetation by anything heats the planet.
As another layperson I suspect this is an incredibly complex issue to assess. Because there are so many different factors determining the effect the sun has on warming the planet. With the bare ground, while the panels would heat up, the ground underneath would be cooler and the earth is a significant thermal mass and can absorb significant heat. But airflows take heat out into the earth’s atmosphere. Plants absorb some of the heat from the solid and turn it into growth. But the panels turn the light energy into electricity, some of which will power processes which generate some heat.
These are very complex relationships which would need intense investigation and analysis, including some very critical assumptions about ratios and efficiencies of conversion. For example, what percentage of panels are placed over fields and what over roofs or other structures. If on a roof, do the panels reduce heat load on “the Earth” or does heat get radiated into the air and how much gets dissipated in other forms? If in a field, what others are benefits realised by the cooler earth underneath eg the higher animal yields I mentioned above?
Thanks goodness we have scientists and computers to do all these incredibly difficult assessments. My layperson’s brain just finds it all too hard.
It doesn’t need to be a direct heat electrical device or electrical losses, everything the electricity is used for is eventually converted to heat.
It pretty much the basic law of thermodynamics.
Using solar radiation to generate electricity, using uranium to generate electricity, using wind to generate electricity, using tides to generate electricity, using waves to generate electricity, etc all heat our planet. Removing vegetation heats our planet. The debate should focus on the environmental damage of using solar radiation to generate electricity. Solar electricity from rooftops does less environmental damage than solar electricity from cleared where vegetation once was.
Kenneth Beer,
“The debate should focus on the environmental damage of using solar radiation to generate electricity.”
Solar panels fight global warming by producing electricity that keeps us from burning greenhouse gas-producing fossil fuels. They also shade the areas below them.
Solar farms have significant gaps between rows of panels, allowing sunlight through to the ground beneath. A multitude of different crops and grasslands can be grown underneath.
https://www.wired.com/story/growing-crops-under-solar-panels-now-theres-a-bright-idea/
Per Carbon Monitor, global CO₂ emissions:
* For the first 8 months of 2022: 98.97 Mt CO₂ / day average
* Compared with 2019: _ +2.9%
* Compared with 2020: +11.6%
* Compared with 2021: _ +2.2%
https://twitter.com/LiuzhuLiu/status/1581988040716980225
Compelling evidence/data I see indicates humanity’s current GHG emissions trajectory puts the world on track for a temperature rise between +2.1 °C and +3.9 °C (relative to the pre-industrial mean surface temperature baseline) by 2100, leading towards likely civilisation collapse.
https://www.pnas.org/doi/full/10.1073/pnas.2108146119
The risk of climate tipping points is rising rapidly as the world heats up.
https://www.theguardian.com/environment/2022/sep/08/world-on-brink-five-climate-tipping-points-study-finds
If humanity cannot rapidly reduce human-induced GHG emissions AND drawdown atmospheric CO₂ concentrations safely well below 350 ppm ASAP, then IMO humanity’s future looks very bleak indeed.
If you read through the article again, you’ll find two reasons given for why solar panel temperatures are usually higher during the day than the surfaces they are above. But just because solar panels tend to get hot during the day it doesn’t mean they are overall contributing to warming the planet. This is because temperature and heat energy, while related, are not the same thing. The same amount of heat energy that raises the temperature of a 20 kg solar panel by 3 degrees will raise the temperature of 20 kg of water by less than one degree. If some of that heat energy is absorbed by water evaporating, its temperature rise will be even less. Overall warming of the earth depends on the total amount of heat energy absorbed and, generally speaking, solar panels mildly reduce this. But exactly what happens depends on the situation, as the article points out.
Some work such as the linked article talk about local heat island effect of large solar farms. I recall seeing something similar in consideration of mega solar farms in the Sahara.
What are your thoughts on this?
Could it be negated by leaving any native scrub untouched as far as possible and raising the height of the PVs or moving them further apart?
Another thought could be to intersperse concentrated solar which should have a cooling effect due to the high albedo of the mirrors (ignoring the thermal storage aspect).
https://www.nature.com/articles/srep35070
Solar farms tend to be hotter during the day but cooler at night and so generally don’t cause overall warming. The simplest way to decrease the daytime heat island effect would be to use panels with reflective, high albedo frames. Another option would be to replace some solar panels with white reflectors. Letting vegetation grow would be another method of reducing it. In dry climates shelter from solar panels can increase plant growth, so it’s not a bad option.
But in most cases the heat island effect of solar farms is a problem only in that higher temperatures reduce the output of solar panels.
Hmm, the article specifically mentions 3.5C hotter at night (clearly shown also in the graphs) and speculates this may be due to trapping of radiated energy by the arrays (as clouds do). In that regard, it doesn’t seem clear if they were taking measurements only under the panel arrays which often take up less than 20% of the “farm” area or both under and between the panels and making an area-weighted average.
Here’s the link about the Sahara, but unfortunately the referred work is paywalled:
https://www.greenbiz.com/article/giant-desert-solar-farms-might-have-unintended-climate-consequences
That article is kind of crazy. It’s talking about covering 20% of the Sahara with solar panels. The Sahara is larger than Australia. 20% of it is the size of Queensland. If you covered that much area with a 5B style solar farm on a sunny day it would generate 46 kilowatts of power for every person on earth. On average it would generate enough energy to supply every family on earth with around 700 kilowatt-hours per day.
I don’t think this is something we really have to worry about.
Ronald, what if that family has a huge aluminium smelter, or a giant car factory or its Twiggy’s place with a humungous liquid hydrogen plant in the backyard. Or my neighbour in this hot sunny place with the newish house with a Woodland Grey roof, the exact opposite of good solar design and a crypto mining supercomputer in bedrooms 3-45?
That may be nowhere enough power for those families with really big demands.
Or industry, for that matter! At least if we keep going the way we are.
People who consume 24 kilowatt-hours a day can trade some of their remaining 676 kWh to people who want more than 700 kWh a day.
Sounds like the coal industry at it again. They still don’t get it. Either way coal is DOA. Blind Freddy could see that.
Perhaps your organisation could make a recommendation on the best value for money battery to choose as well. Flogging the Tesla battery may not be the way to go.
Given its current price, I can’t recommend the Tesla Powerwall to anyone who doesn’t have buckets of money. If it comes down in price, then it’s fine.
I have two sons with Tesla Powerwalls and they have been fabulous over the last 3 years. Both were picked up with cheap government loans and also a bit of a subsidy.
No they’re not cheap, but they are otherwise fabulous.
I’m ever hopeful that 1. They will switch to LFP batteries (like the RWD Teslas), and 2. The price will come down.
I hope I’m not dreaming.
The coal industry, like the tobacco industry, know full well that their product is unsafe to use and know that is being phased out progressively. But of course, their interest is in making money while they can. Therefore they will use whatever tactics they can get away with, as does the tobacco industry here and around the world, to achieve that objective. They are being helped by the current high prices of coal of course, caused by a range of factors including the Russian invasion of Ukraine. And we have some of the “cleanest” ie a bit less dirty to be more accurate, coal for burning in the world to export, so they are making hay while the sun still shines.
But in time, although who knows exactly how long, coal will phase out for obvious reasons and other energy sources will replace it. And it will probably be much sooner than smoking of tobacco will cease.
So what you are saying is we are all going to be eaten by saber tooth tigers and trampled to death by woolly manouths( sorry about the spelling but I am saying solar panels means the return of the ice age and my tin foil hat is at the cleaners)
Yes, that’s definitely what I’m saying. The ice that forms under solar panels during the Australian summer and the little mammoths that roam across it are just harbingers of what’s to come.
Ron
I was of a similar view to you about the potential of solar panels creating Heat Islands (PVHI) based on what I’d expect of the energy balances involved.
However a study published in Nature of actual operating PV installations demonstrates that larger solar power plants significantly increase local temperatures.
The study conducted in Arizona in semi desert areas similar to locations we have in Australia demonstrates that the PVHI effect is real and can significantly increase night temperatures by 4 Deg C relative to nearby wildlands.
https://www.nature.com/articles/srep35070