Forget the phrase about water and electricity not mixing. Floating solar farms are the latest part of a solar power revolution.
As people have become accustomed to seeing large-scale solar systems on land, floating solar plants could be the next big thing. With climate change and extreme weather events taking grip, the demand for green energy increases.
Indeed, according to the International Renewable Energy Agency (IRENA), 90% of all electricity production can come from renewable energy sources, helping us on the path to net-zero greenhouse gas emissions by 2050. Encouragingly, the falling costs of renewables means solar is now the cheapest new power generation to install. Even the math shows the days of fossil fuels should be numbered.
Floating solar farms may sound like next-generation tech, but this niche and nascent industry is already making a splash. So put on your rain boots and get ready to walk on water as we visit the world of floating solar plants.
What Is a Floating Solar Farm?
A floating solar farm is a group of solar panels attached to a structure that floats on a body of water. The solar panels are classic photovoltaic (PV) panels on homes and at solar farms.
These structures float on water bodies like hydropower reservoirs, drinking water reservoirs, lakes, canals, and water treatment ponds. They are sometimes called floating photovoltaic systems or floatovoltaic systems.
They can also be immense. One of the world’s biggest floating solar farms in Dezhou, China, can be seen from space.
The solar arrays generate electricity and send it to a transmission tower through underwater wires. This energy can either be used locally or added to a power grid.
How Do Floating Solar Farms Stay Afloat?
Solar modules weigh up to 50 pounds (22kg) each. Therefore, a solar array of hundreds of panels requires a vast number of buoyant structures to stay afloat.
These buoyancy devices are usually made from polyethylene, a standard plastic found in kitchenware and containers. This material helps prevent rust.
Why Do We Need Floating Solar Plants?
Solar and onshore wind farms are popular renewable energy sources. The world has seen a 12-fold increase in solar capacity in the last 10 years to a whopping 1,053 gigawatts in 2022.
Solar energy requires much more space than fossil fuel power plants like coal and natural gas to create the same amount of electricity. The U.S. alone may need panels covering an area the size of California to make the shift and meet its electricity needs from clean energy.
And for such large-scale demands, solar farms require something the Earth cannot replenish: land. In short, society needs more land to generate enough electricity from clean energy sources like solar. This is vital in countries like Japan, where land is scarce and expensive.
That’s where the floating solar farms step in. By sitting atop water bodies, floatovoltaic systems make the most of the surface areas available across countries. The industry expects 15% annual growth until 2031, with 70% of all installations in China, India, and Indonesia.
What Are the Advantages of Floating Solar Farms?
Floating photovoltaic panels open up huge areas to power generation possibilities. Valuable land can be kept for agriculture, as wilderness, or protected. There are also lots of technical advantages to floating solar arrays.
Land or roof-based solar panels work best between 59-95 degrees Fahrenheit (10-35 degrees Celsius). However, they function less efficiently at higher temperatures, becoming between 10-25% less productive. In contrast, floating solar panels cool naturally thanks to the presence of the water beneath it. That helps them maintain optimum performance, even when temperatures soar.
Many land-based solar farms are in rural areas and require maintenance, regularly cleaning away dirt and debris to ensure efficiency. Floatovoltaic arrays have less contact with ambient dust, staying cleaner longer. Water can also be drawn from below the floating structure to clean them, minimizing waste.
Reservoirs covered with a floating solar plant experience less evaporation, protecting a valuable asset. A reservoir in Jordan reduced evaporation by 42% thanks to its floating solar panels. They also have less impact on local fragile ecosystems as utility-scale land-based solar farms often upset local wildlife, vegetation, and views.
The protective layer provided by floating solar farms may also restrict toxic algae blooms. These can erupt during hot weather spells, but the panels help shade the bodies of water, keeping them cooler by stopping them from absorbing the sun’s rays.
Pumped hydro storage offers another plus for floating solar farms. Water stored in a higher lake cascades through turbines to create electricity, which either flows away or is stored in a lower lake.
A local floating solar farm could generate electricity to pump the lower lake water up to the higher lake during the day. At night, the higher reservoir would release the water to create more electricity and then repeat the daytime shifting of water back to the higher reservoir. This system creates an efficient green energy loop, perfect for sustainability.
These floating electricity generators can also follow the sun by tilting as it arcs through the sky, increasing efficiency by up to 35-40% compared to static solar panels.
What Are the Disadvantages of Floating Solar Farms?
Floating solar installations are not a panacea for the world’s rising energy production needs.
First up is the fact that floating solar farms are more expensive to install than their land-based cousins, with estimates at 20-50% extra. Special care must be taken with exporting electricity from the floating beds, mainly if animals or humans use the water. Cables also must be extra secure.
On an environmental level, fish stocks in bodies of water with floating solar arrays may also be harmed due to changing conditions, affecting biodiversity.
The buoyancy devices supporting floating solar plants cannot withstand wavy or rough environments. Storms and high winds, as well as strong tidal forces, can displace them if not properly anchored. For that reason, most floating solar farms are situated on calmer inland waters or reservoirs rather than out at sea. That said, oceans offer more capacity for growth.
Saltwater environments would also bring in corrosion issues alongside difficulties in maintaining a floating raft of solar panels out at sea. General wear and tear can result in catastrophic failure of floating plants.
Reservoirs are often popular with water sports fans like swimmers, kayakers, and fishers. It’s not hard to see how floating solar panels could aggravate local feelings and impinge on people’s recreational activities.
Research is ongoing on how floating solar farms react in cold weather. For example, how would a freezing lake affect the buoyancy structures?
Where Can You Find Floating Solar Farms?
There are floating solar farms worldwide despite the industry being relatively fledgling.
For example, it was back in March 2016 that Europe’s then-largest floating solar farm started producing electricity on the Queen Elizabeth II Reservoir near London.
The plant can generate 6.3 megawatts (MW) of electricity to power 1,800 homes. However, the construction figures demonstrate the initial high investment required to get projects moving.
Some 23,046 solar panels require 61,000 floats and 177 anchors attached by professional divers for an array with an area of 57,000m2. That’s around 10% of the lake’s entire surface.
Holland has since opened a 41.4 MW floating solar farm at Sellingen. But both of these pale into insignificance compared to behemoths revealed in recent years.
Where Are the World’s Largest Floating Solar Farms Built?
The floating solar farm revolution is not happening in Europe, the Americas, or Africa. Asia is once more the leader in the green energy race.
China already leads the way for solar panel capacity, generating more solar electricity than all other countries combined. Together with India and South Korea, China has grabbed the potential of floating solar farms and sailed off into the sunset while others experiment with solar projects.
There are lots of mega-projects in the pipeline that will soon overshadow the current market leaders.
Where Is the World’s Largest Floating Solar Farm?
The current largest operational floating solar farm is the Dezhou Dingzhuang Floating Solar Farm in Dezhou, China. The site offers 320 MW of electricity.
Dezhou surpassed the 150 MW that has been online since 2017 at the Three Gorges New Energy Floating Solar Farm in Huainan City, China.
The eye-raising figures come from what is in the pipeline.
The world’s largest planned floating solar farm will offer an incredible 2.1 GW of electricity, six times more than Dezhou. South Korea will build the array on a tidal flat at Saemangeum in the Yellow Sea. It will cover more than 11.5 square miles (30 square kilometers) and comprise more than five million solar modules. The Korean government had to assure a nearby U.S. military base that the colossal structure wouldn’t create a glare hindering its local operations.
In India, the Narmada River, which feeds the Omkareshwar dam in Madhya Pradesh, will soon be covered by 2,000 hectares of solar panels. Once complete, the site will generate up to 600 MW of electricity. A further 100 MW floating solar project is reported for Telangana.
Indonesia has also proposed a 145 MW floating PV project at its Cirata Reservoir in the West Java region. Singapore has a 60 MW floating solar farm at the Tengeh Reservoir.
Compare that to Germany, often credited for its positive approach to environmental matters. The country announced its largest floating solar farm in Karlsruhe, at 15 MW. Clearly, floating solar still has a road to travel.
Where Is the Largest Floating Solar Power Plant in the United States?
“New Jersey is now home to the largest floating solar power plant in the United States.
With 8.9 MW capacity, the solar project at Canoe Brook Reservoir in Short Hills, New Jersey, covers 17 acres. It will power around 95% of New Jersey American Water’s Canoe Brook Water Treatment Plant.
New Jersey has taken over from the previous leader, the 4.8 MW floating solar plant at Healdsburg, California. The site’s 11,600 double-sided solar panels capture direct sun rays and those that reflect off the water, helping it provide 8% of Healdsburg’s annual electricity needs. But these are very small solar projects compared to Asia’s efforts.
Can I Get a Floating Solar Farm for My Home?
Floating solar plants are industrial scale at present. Most homeowners don’t own a pond or lake large enough to install enough solar panels to make a floating solar farm worthwhile.
Couple that with the extra costs and it makes more sense for homeowners and renters alike to install or lease ground-mounted or rooftop solar panels, depending on the price of solar panels.
Floating Solar Farms Can Help Battle Climate Change
Floating solar farms—solar panels atop floats—are fast becoming vital to the battle against climate change while maintaining our relationship with energy production and consumption.
Just like rooftop or ground-mounted panels, solar energy from floating panels helps reduce carbon emissions. However, their key advantage is allowing us to leave land for agriculture, wilderness, and places to live.
Floating on drinking-water reservoirs, lakes, and other bodies of water protected from waves and extreme weather, floating solar farms don’t take up any extra space. Assuming their base is secure, they require less maintenance than land-based solar panels and extra efficiency.
Asian countries have embraced the floating solar farm revolution much more than the rest of the world. The technology’s mainstream success depends, perhaps, on evolution. A floating solar array that can survive at sea or in more challenging environments would be a game-changer, opening up vast swathes of the ocean as potential renewable energy hotspots.
Brought to you by amigoenergy
All images licensed from Adobe Stock.