Giles Exley, Lancaster University
Solar power is now the cheapest source of electricity in history, according to a 2020 report by the International Energy Agency. But there’s something holding this clean energy powerhouse back: space. Unlike fossil fuel power stations, solar farms need a lot of room to generate enough electricity to keep up with demand. Most solar farms are composed of ground-mounted panels that take up land that could be used to grow food or provide habitat for wildlife.
Although electricity and water don’t usually mix, a growing number of floating solar farms are being deployed worldwide. Floating solar panels on a lake or reservoir might sound like an accident waiting to happen, but recent studies have shown the technology generates more electricity compared with rooftop or ground-mounted solar installations. This is thanks to the cooling effect of the water beneath the panels, which can boost how efficiently these systems generate electricity by as much as 12.5%.
That said, lakes and reservoirs are already very important for people and the planet. While these freshwater bodies cover less than 1% of Earth’s surface, they nurture almost 6% of its biodiversity and provide drinking water and crop irrigation that’s vital to billions of people. Worryingly, climate change has raised the surface temperatures of lakes globally by an average of 0.34°C per decade since 1985, encouraging toxic algal blooms, lowering water levels and preventing water mixing between the distinct layers which naturally form in larger and deeper lakes, starving the depths of oxygen.
In the rush to decarbonise energy in order to slow global warming, might turning to floating solar farms simply add to the strain on the world’s precious freshwater reserves? Remarkably, in new research, we found that carefully designed floating solar farms could actually reduce the threats posed by climate change to lakes and reservoirs.
A buffer against warming
Along with colleagues, I used a computer model to simulate how floating solar farms are likely to affect lake water temperatures. Our simulations are based on Windermere, the largest lake in England and one of the most well-studied lakes in the world.
Floating solar farms reduce how much wind and sunlight reaches the lake’s surface, changing many of the processes that occur within. As each floating solar farm has a different design, we ran simulations to see how lake temperatures changed with over 10,000 unique combinations of wind speed and solar radiation.
Our results suggest that the changes to water temperatures caused by floating solar farms could be as big as climate change itself, only in the opposite direction.
A floating solar farm that reduces wind speed and solar radiation by 10% across the entire lake could offset a decade of warming from climate change. Designs that shaded the lake more than sheltered it, by reducing sunlight more than wind, had the greatest cooling effect. Evaporation fell and the lake was mixed more frequently, which helps oxygenate the deeper water.
These effects might vary depending on a lake’s depth, surface area and location. But ecological processes in lakes are most affected by wind speed and sunlight, which is what our simulations focused on.
Global potential
While most of our simulations indicated a win-win for lakes and floating solar farms, some suggested undesirable side effects. In a small number of simulations, we found that floating solar farms that reduced wind speed at the lake’s surface more than they reduced sunlight might actually mimic or amplify the effects of climate change, increasing how long deeper lakes remain stratified. Thankfully, we think the careful design of floating solar farms should reduce these risks.
Floating solar power has grown more than a hundredfold in the past five years, reaching 2.6 gigawatts of installed capacity across 35 countries. If just 1% of the surface area of all human-made water bodies (which are easier to access and typically less ecologically sensitive than natural lakes) was covered by floating solar panels, it could generate 400 gigawatts – enough electricity to power 44 billion LED light bulbs for a year.
Floating solar is likely to make an important contribution to the decarbonisation of the world’s energy supplies. In a stroke of serendipity, our research suggests this could have the added benefit of offsetting part of the damage to lakes caused by rising temperatures.
Still, our simulations only covered the physical effects of floating solar, while other questions remain unresolved. How would floating solar farms interact with other lake uses, such as sport or aquaculture? How would the wildlife sharing the lake fare? And which lakes are best suited to hosting a floating solar farm? The work to fully understand the potential of this technology is only just beginning.
Giles Exley, Associate Lecturer of Energy and Environment, Lancaster University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
As a Marine Biologist this concerns me as these floating solar farms are draining energy and heat from water and the organisms that depend upon it. The stupid – it hurts. I got asked today if I was allergic to anything and I said YES Stupidity
Solar Panels floating on blocks of Styrofoam made from petroleum. Priceless!
The doomsters call that transitioning. Just that they haven’t quite transitioned the lakeside getaway owners and sundry NIMBYS around the idea with their local lakes just yet.
A 10-cent engineering analysis:
1) the flotation system is an added balance-of-system cost, which must be engineered for the lake environment
2) this is a wet environment that can only increase reliability problems for the PV modules caused by small leakage currents, especially corrosion and loss of insulation—reduced module lifetime and higher costs due to power losses
3) the inter-module string wiring has to be rated for immersion—extra cost
4) horizontal array orientation—greater cosine losses compared with tilted arrays
5) as others here have noted, winter and ice will be a problem that can likely only increase costs
6) because of #2, modules will almost certainly have to be double-glass, i.e. glass sheets for both front and back surfaces—these are twice as heavy, which will affect #1
So this is cheaper? How?
Meanwhile they’re cooling down rooftop solar exports in South Australia-
Solar export limits for Adelaide suburbs with most panels under SA Power Networks trial (msn.com)
Interfering with water evaporating from the surface to allow evaporative cooling plus form sunlight reflecting clouds…is just NOT a good idea for controlling the planet’s temperature.
I have to admit this article has me laughing so hard so long it made my week.
It is bad enough that we are occupying so much land for wind and solar energy. Now to do it to our lakes is ridiculous. Lakes have their own beauty and this would ruin that affect. These environmental extremists need to be shut down. They are way over the top with their ideas.
what warming ? the US has been cool for last 50 years
I have asked this for years, watt happens to a given envioronment when we capture current natural dynamic energy (solar, wind or ??–as opposed to energy that was captured over millions of years), convert it to electricity, and ship it off elsewhere–instead of letting it do what nature intended?
Yep, lets float electric generators on the lake — what could POSSIBLY go wrong with that? (err … waterproofing the solar array, wear on the electrical cabling to shore, maintenance costs, guying the whole thing down during storms, cutting off essential sunlight to aquatic life, no more fishing allowed, etc …)
“But there’s something holding this clean energy powerhouse back”:
Let me guess…
It doesn’t work at night, and sometimes even in the day?
It’s efficiency reduces over time?
It involves obtaining an interesting mix of non-green chemicals?
It’s great for keeping your RV batteries topped up, but utterly useless for powering a modern civilisation?
Must have missed original publishing date by two weeks,me thinks.
Quote:”Giles Exley, Lancaster University
Solar power is now the cheapest source of electricity in history, according to a 2020 report by the International Energy Agency”
I’ve said for a long time, ever since I was born and lived in Cumbria (used to be ‘Cumberland’ and bang next door to Lancashire)
“The only good thing to come out of Lancashire is the M6 Motorway”
I have changed my mind, a little, to include Pendolino trains on the West Coast Mainline and Eccles Cakes
Even the mighty haha Wiki gets it wrong. (Tell me you’re shocked)
They are = ‘Dead Fly Pies‘
Isn’t ‘Insect Eating’ now the Soup-du-Jour’
Thus, eat Eccles Cakes and Save The World!
So there is a modicum of hope for Lancashire, the glimmer of a GSOH
So much junk in there, my chosen points:
1) The lakes are warming up because the rivers and stream feeding them have warmed up. Tillage and deforestation i.e. Albedo reduction of the (farm) land
2) Solar panels get extremely hot under a bright sun, way way too hot to touch.
That heat conducts into the air where it will be recorded by thermometers – which will attribute it to Global Warming. It will not have the effect claimed
3) Someone ought to whisper in the guy’s ear the two little words “Loss Leader”
The Chinese are flogging panels dirt cheap and watching with what can only be incredulous joy, as Western Societies switch off their power stations and then, raze them to the ground
When sufficient damage has been done, just watch the price of solar panels skyrocket.
Exactly as the price of Chinese sourced Neodymium did (is there any other sort) when western windmill makers said they were going to use it in the next generation of turbines. The retail price for Neodymium went up by a factor of 20 (twenty)
What would happen to electricity prices when most of the Fossil Fuel Plants are decommissioned & destroyed and solar panels experience the same ‘effect’?
The turkeys really are Voting for Christmas, these people are criminally negligent and insane.
No matter,
BorisPrincess Nut Nuts has it all under controlHuge solar farm
Never mind that the UK produces less than half the food it consumes.
The turkeys, as hang-out around The Grauniad, have been convinced of ‘Excess UK Farmland’ for some little while now…
Quote: “Up to 17% of cropland and 30% of grassland could be converted, the report says”
Also here,
Quote:”Following the blah blah, the Independent Panel on Forestry recommended that the government should commit to increase woodland cover in England from 10% to 15% by 2060″
Wonder if Nut Nuts and Boris will change their tune now most of the French wine crop has gone down the pan? What will they use to hold their happy little family together then…
And in the 4th link there, he actually slags off Single Mothers – and then goes on to create one, while = Prime Minister.
How dumb is it possible to be?
Maybe ‘The Johnsons’ have a Wine Printing Machine, similar to the one that prints money. Also UK farmland.
Think we’d all like a bit of that action…
(Am I actually The Crazy One, wtf is going on here)
Here’s a real life example
Thames Water installs Europe’s largest floating solar panel project (waterbriefing.org)
This is a drinking water reservoir, built in concrete,off limits to the general public and not full of wildlife
‘The design of the reservoir has an effect on the fish population that can live in the reservoir, the concrete shores means that only European perch and ruffe can breed, except for where there are empty fish cages constructed with netting, which support some plant growth and this allows small numbers of cyprinid fish to breed. The low numbers of fish in the reservoir have led to the zooplankton being dominated by large sized cladocerans and Daphnia and to high growth rates in the few fish that live there.’
So you are good with poisoning public drinking water with the toxic materials contained in solar panels. Again you show yourself to be an idiot.
Oh, and migrating waterfowl don’t care about a fence and signs, they land on it anyway.
Solar obviously isn’t cheaper or more people would be buying it. There’s plenty of space in most countries as well. So the proposal starts out with two incorrect statements. Now let’s look at the idea. Most countries either don’t have an issue with lakes warming or they don’t have enough surface water in the first place. Most issues with lakes involve polluted water because they don’t treat sewage, or the country uses too much water from the streams feeding the lake. Then there are storms, which you can design for on land. Add a large swell to your floating design. The costs increase. After all, those PV panels are pretty expensive, can’t let them flex too much or they break. Water is the number one cause of PV panel breakdown. At least there will be plenty of water to wash down the panels so they retain their performance.
Floating solar may mimic or amplify the effects of climate change.
Good grief, you couldn’t make it up.
So, you’re saying The Big Lie is a real thing?
the conversation…it’d figure!
so the solar cells gain cooling but theyd be reflecting heat as well..
and a flood might be a problem?
wonder how theyd go with duckcrap etc when the birds get brave enough to land on em?
More confirmation that the world is being taken over by permanent ten year-olds so enchanted with their play-toy science fair projects they can’t grasp the inescapable waste and damage they cause.
Oh, what a wonderful idea! Let’s cover the Everglades with solar panels too! That will kill all of the invasive species too while preventing warming!
/sarc
LOL! I can just see that working in northern lakes when they freeze over and start cracking the panels. Also great in the spring when the ice breaks up and the wind pushes it around. Also great for people living around those lakes who want to use them for recreation and fishing. Also great for birds and wildlife around those lakes.
Dumb idea of the century.
Power out in the winter would likely be nearly zero.
I wonder how many more years we have before our insane ideas actually destroy the planet and kill us all?
Finally an answer as to why there are no fish in my pond.
I see two problems here. First: “This is thanks to the cooling effect of the water beneath the panels” – that would suggest WARMING of the water, since a “cooling effect” is due to a transfer of heat from the warmer object (panels) to the cooler object (water).
But, accepting for sake of discussion that is more than offset by the cooling of the water due to less sunlight, this seems pretty classic first-order thinking. Yes, we cool the lakes. What are the impacts of doing so?
I wouldn’t try this in places where the lakes freeze over in the winter. Of course, locations at latitudes high enough for that to happen are stupid places to put solar farms anyway.
The authors must be congratulated on their miraculous modeling as at one stroke they have demolished the requirement for subsidies and have improved the efficiency of photovoltaic cells so as to actually cool the surrounding environment while using bodies of water as heat sinks. I am truly astounded. One difficulty I have with the cost benefit analysis is that, especially in the higher latitudes of the globe, to receive sunlight perpendicular to the cells you must find lakes located on the sides of mountains at the proper orientation to the sun. It is my experience that these lakes are rare and are extensively used for downhill water skiing. This minor quibble aside, I am in awe!