FACT or MYTH Series: #1
Do Floating Solar Arrays negatively affect water?
MYTH. Floating Solar does not hurt bodies of water - in fact, the technology helps it in multiple ways! What hurts bodies of water is when there is nothing there. Read on to learn how this works.
December 16th, 2021
Floating solar actually improves the health of the body of water that it sits upon.
Some improvements include: prevention and offsetting of decades of warming from climate change, reduced evaporation, reduced algae growth due to sunlight insolation, and elimination/reduced costs associated with Algae Water Treatment.
Let's explore further how floating solar is a key player in the reversal of rising water temperatures.
Fresh bodies of water are becoming more and more critical to the planet as climate change is causing more and more of them to shrink and even dry up. Fresh bodies of water cover less than 1% of the surface of the earth, yet they also house more than 5% of varieties of life on the earth. These bodies of water also provide for drinking water, irrigation, and water treatment: non-negotiable necessities for the wellbeing of life on earth. Unfortunately, climate change has raised the surface temperatures of lakes globally by an average of .34 degrees C per decade since the 1980s. The increased temperatures promote toxic algae blooms - meaning less healthy water overall.
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"In fact, as of this morning the average surface water temperature on [Lake Michigan] is around 2°F warmer than 2016, which had been warmest on record dating back to 1995," National Weather Service report on Lake Michigan. Credit: Alanna Williams, Detroit Free Press, October 23, 2021
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FACT: New research has shown that carefully designed floating solar farms could actually reduce the threats posed by climate change to lakes and reservoirs.
How is this possible? Floating solar farms reduce how much wind and sunlight reaches the lake’s surface, changing many of the processes that occur within.
In a groundbreaking study performed by Giles Exley, Associate Lecturer of Energy and Environment, Lancaster University, evidence was found, proving the potential that solar has towards the reduction and offset of warming from climate change.
"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.
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."
With the conservative numbers from National Renewable Energy Laboratory (NREL), it has been estimated that roughly 14,000,000 acres or 22,000 square miles of solar panel-filled land would be required to generate enough electricity to solar-power the U.S. Land-based solar takes 5 times more area to generate the same power as floating solar.
With about 4,500 square miles of bodies of water or about 2% of the total freshwater area, we could power the US and have healthier bodies of water!
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Credited Sources Include:
Exley, Giles. “Floating Solar Farms Could Cool down Lakes Threatened by Climate Change.” The Conversation, Lancaster University, 28 Apr. 2021, https://theconversation.com/floating-solar-farms-could-cool-down-lakes-threatened-by-climate-change-157987.
“Solar Research.” NREL.gov, https://www.nrel.gov/solar/index.html.
Williams, Alanna. “Lake Michigan Has Record-Breaking Temperatures for Late October.” Detroit Free Press, Detroit Free Press, 23 Oct. 2021, https://www.freep.com/story/news/local/michigan/2021/10/23/lake-michigan-water-temperature-2021/6154971001/.
Alona Armstrong et al 2020 Environ. Res. Lett. 15 114055. Link