If solar energy use is to grow significantly, covering many rooftops and land plots with photovoltaic (PV) modules will be essential. While rooftops are often ideal for solar panels, not all are suitable, and vacant land in urban and suburban areas can be scarce and expensive. One innovative solution to this problem is to tap into the vast areas of water covering the Earth to generate solar power.
As a result, floating solar systems, also known as floatovoltaics, are gaining popularity for certain applications. But are floating solar panels the next big thing in clean energy, or are they too expensive and impractical? Let’s dive into this innovative technology to better understand its potential.
What Are Floatovoltaics?
Floating photovoltaics (FPV) projects involve solar modules that float on water bodies like lakes, ponds, reservoirs, and rivers. These PV panels are elevated above the water’s surface, usually mounted on durable, buoyant structures that are resistant to rust. Floating solar farms are becoming more common, especially in densely populated areas where available land is limited or too costly.
Floating solar farms are typically found in hydroelectric dam reservoirs, drinking water reservoirs, and wastewater treatment ponds—disturbed sites where hydropower plants have existing infrastructure for power transmission.
Some developers are even exploring offshore solar farms mounted at sea. Since oceans cover about 70% of the Earth’s surface, there is vast potential for PV panel installation. However, deploying floating solar panels in open seas presents its own set of challenges.
Potential Benefits Of Floatovoltaics
Locating utility-scale renewable energy projects near population centers is ideal, but available land in urban areas is often scarce and expensive. In rural farming communities, there is concern that converting farmland into utility-scale solar farms could impact food security. However, floating solar, or floatovoltaics, offers a solution by taking up little or no land space and utilizing areas with minimal other development potential.
One significant benefit of floating solar farms is their ability to naturally cool the solar panels. Solar panel efficiency typically drops when temperatures rise above 77°F, with most panels having a temperature coefficient of -0.3%°C to -0.5%°C. This means the hotter the panel, the less efficient it becomes, reducing overall solar power output. However, mounting solar PV panels above water helps cool them, boosting their efficiency and increasing energy production. Also, using bifacial solar panels on floating solar farms allows the panels to generate power from both sides, capturing light that reflects off the water’s surface.
Another advantage of floatovoltaics is their ability to help shade the body of water, reducing freshwater evaporation. This can be particularly beneficial in dry climates or during droughts. A 2021 study found that covering 4,000 miles of California canal with solar canopies could conserve 65 billion gallons of water annually by preventing evaporation. California, therefore, holds immense photovoltaic potential.
Installing floating solar farms at hydroelectric dam reservoirs also provides the advantage of utilizing existing utility infrastructure, which can significantly lower development costs. Furthermore, solar engineers are exploring combining offshore wind farms and floating solar farms, allowing them to share the same transmission infrastructure. For instance, a 5-megawatt floating solar project is planned for the North Sea near the Netherlands, with operations slated to begin in 2026.
Current Roadblocks For Floating Solar Farms
While floatovoltaics offer numerous benefits, there are still challenges to address. One major issue for floating solar farms in saltwater environments is the accumulation of salt residue on the solar panels, which can reduce energy output. Even land-based solar projects near the ocean can experience similar efficiency losses due to salt spray.
Because floating solar farms are less common, they require specialized equipment to keep the panels above the water’s surface. Unlike standard roof or ground-mounted systems, floating solar installations demand more complex and costly racking solutions. As a niche market, the higher material costs can drive up the overall expense of these projects.
Engineering complexities also pose challenges. Floating solar farms must withstand high wind speeds, water movement, corrosion, and anchoring difficulties. Site selection can be particularly time-consuming, increasing permitting issues and raising development and construction costs.
Another concern is the potential environmental impact of floating solar. Constructing floating solar power plants can disturb aquatic ecosystems, especially in sensitive environments. Once installed, the panels shade the water’s surface, reducing available sunlight and altering aquatic life. Studies suggest that floating solar farms can affect water stratification, leading to lower oxygen levels in deeper layers, which may increase nutrient concentrations and harm fish populations. Further research is needed to fully understand the ecological effects of floatovoltaics.
NEC Guidelines for Floatovoltaics
The National Electrical Code establishes critical safety standards for all electrical installations, including floating solar farms. Since floatovoltaics operate in water environments, they must meet stringent NEC requirements to ensure safety, reliability, and durability. Key considerations for floating solar projects include:
Grounding and Bonding (NEC 690 & NEC 250)
Proper grounding is essential to mitigate electrical hazards in floatovoltaic systems. Floating solar structures require specialized grounding techniques to prevent stray currents and potential shock risks. NEC 250 outlines grounding requirements, while NEC 690 specifies bonding for PV systems, ensuring safety and compliance.
Wet Location Requirements (NEC 682 & NEC 690.31)
Because floating solar farms are installed over water, they are classified as “wet locations” under NEC 682. This requires all electrical components—wiring, junction boxes, and inverters—to be corrosion-resistant and enclosed in watertight, marine-grade materials. NEC 690.31 mandates that solar wiring used in floatovoltaic systems must be rated for wet environments and protected against UV exposure.
Wiring Methods & Insulation (NEC 310 & NEC 334.12(B))
All conductors in floating solar installations must be suitable for continuous exposure to water, humidity, and mechanical stress. NEC 310 mandates the use of THWN-2 or XHHW-2 conductors, which are water-resistant and UV-rated. NEC 334.12(B) also prohibits the use of non-metallic sheathed cables in wet locations, ensuring durability in floatovoltaic applications.
Overcurrent Protection & Disconnects (NEC 705.12 & NEC 240)
Floating solar farms require robust overcurrent protection due to their proximity to water, reducing risks of short circuits and system failures. NEC 705.12 specifies proper breaker coordination for floating PV systems, while NEC 240 outlines fuse and circuit breaker selection to prevent electrical fires or arc faults.
Maintenance & Safety Access (NEC 110.26 & NEC 690.4(E))
To ensure safe operation, floatovoltaics must allow adequate space for maintenance, inspections, and emergency shutdowns. NEC 110.26 establishes working clearance requirements, while NEC 690.4(E) ensures floating PV arrays have proper labeling and rapid shutdown capabilities for technician safety.
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What are the Pros and Cons of Floatovoltaics?
The rise of floating solar farms presents both opportunities and challenges for renewable energy expansion. Here’s a breakdown of the pros and cons of floatovoltaics:
Pros of Floatovoltaics
✅ Additional solar energy generation without occupying valuable land
✅ Utilization of water bodies like reservoirs, ponds, and hydroelectric dams
✅ Water cooling effect boosts solar panel efficiency and energy output
✅ Reduction in water evaporation, preserving water resources
✅ Prevention of algal blooms and control of evaporation-induced salinity
✅ Potential ecological benefits for aquatic vegetation and habitat shading
✅ Dual land use for renewable energy and water conservation
✅ Reduced land-use conflicts, making solar development more feasible
✅ Aesthetic appeal and potential for higher public acceptance
Cons of Floatovoltaics
⚠️ High initial installation costs due to specialized floating solar panel structures
⚠️ Potential impact on aquatic ecosystems and water stratification
⚠️ Maintenance challenges for cleaning and servicing floating solar panels
⚠️ Limited scalability on small or irregularly shaped water bodies
⚠️ Possible shading effects on aquatic life and water temperature regulation
⚠️ Restricted use in colder climates, where ice formation is a concern
⚠️ Regulatory and solar permitting complexities for water-based installations
⚠️ Limited long-term data on the performance and durability of floating PV systems
⚠️ Site-specific floatovoltaics challenges, including anchoring, wave action, and wind loads
What Floatovoltaic Projects Exist Today?
Floating solar farms are gaining momentum worldwide, with numerous countries investing in large-scale floatovoltaics to expand clean energy capacity. While some projects are already operational, others are in various stages of development.
China
The largest operational floating solar farm project is Dingzhuang solar farm in eastern China. This 320 MW floating solar panel system is mounted on a reservoir and integrates a 100 MW wind farm with 8 MWh of battery storage. Developed by Huaneng Power International (HPI), it is situated near the 2.65 GW Dezhou thermal power station, helping China transition toward renewable energy.
Taiwan
One of Taiwan’s largest floating solar farms is located in the Changbin Industrial Zone, with a total installed capacity of 440 MWp. This floatovoltaic project, developed by Ciel & Terre Taiwan, expands on a previous installation from 2020. The project supports Taiwan’s renewable energy targets while reducing carbon emissions.
South Korea
The largest floatovoltaics project is the Saemangeum floating solar farm in South Korea. This 2.1-gigawatt project aims to be operational in 2030 and can help the country significantly reduce its dependence on fossil fuels. It will be located in tidal flats on the Yellow Sea coast, co-located with an onshore solar farm.
India
India is constructing the 600 MW Omkareshwar floating solar panel farm on the Narmada River, which is set to be the largest floatovoltaics installation in the world. Developed by Rewa Ultra Mega Solar Limited (RUMSL), the project will utilize the Omkareshwar Dam reservoir in Madhya Pradesh to generate clean energy while maximizing space efficiency.
North America
The largest floating solar farm in North America is the NJR Clean Energy Ventures (CEV) floating solar project in Millburn, New Jersey. With a capacity of 8.9 MW, it features 16,510 floating solar panels installed on a reservoir at the New Jersey American Water Canoe Brook Water Treatment Plant. This project highlights the benefits of floatovoltaics, including reduced water evaporation, water protection, and environmental sustainability.
Europe
Portugal’s Alqueva floating solar farm is the largest in Europe, with nearly 12,000 floating solar panels covering an area equivalent to four football fields. With a 70 MW capacity, this floatovoltaic system is part of a larger hybrid farm expected to reach 154 MW in total capacity, contributing to Portugal’s clean energy transition.
Also, SolarDuck, a Dutch-Norwegian floating solar company, is developing a 500 kW offshore pilot project in the North Sea. This initiative will test the feasibility of offshore floating solar panels, demonstrating how floatovoltaics can complement offshore wind farms and expand renewable energy production.
How Much Do Floating Solar Panels Cost?
The cost of floating solar farms varies depending on numerous factors, including the cost of anchoring systems, transmission infrastructure, real estate leases, labor, and system capacity. For example, the Saemangeum floatovoltaics project is estimated to cost $3.82 billion, and the smaller floating solar farm on the Narmada River costs $4.1 million.
Some more experimental projects, such as the Dutch project in the North Sea, are still in the pilot phase. Thus, floatovoltaics are much more expensive per MW because they are smaller in scale and require more research.
What Research Is Needed to Advance Floatovoltaics?
More research is needed to improve the efficiency of current floating solar panel systems and lower their costs to advance floatovoltaics. Researchers can further analyze the impacts of environmental factors like wind and waves on solar panel orientation and positioning and develop better anchoring systems.
Efforts can also be directed towards creating more environmentally friendly materials for floating solar panel systems, ensuring that installations do not harm marine ecosystems. Finally, there is also a need for research on the most effective integration of floating solar photovoltaic systems with existing onshore and offshore renewable energy infrastructures to improve energy storage and distribution.
What Companies Specialize in Floatovoltaics?
Several companies specialize in floating solar panels. One such company is D3Energy, a leader in floating solar applications, having developed and constructed numerous systems in the United States. They specialize in all aspects of floating PV systems, from design and engineering to construction and maintenance.
Another company involved in floating offshore solar projects is SolarDuck, a Dutch-Norwegian developer planning a 500-kilowatt offshore pilot project in the North Sea. Solarduck is known for its innovative floating solar solutions that are designed to withstand harsh offshore conditions while maximizing energy production and minimizing environmental impact.
Floatovoltaics: Solar Installations Of The Future?
Although floating solar panels are promising in certain areas, they are not ideal for all locations. This application is most appealing in areas where land is scarce, and existing transmission infrastructure is in place. Often, the most attractive sites are reservoirs at hydroelectric dams, but some solar developers are examining ocean-based applications at offshore wind farms and tidal flats.
Although many floating solar projects have been completed, more research is needed to advance this approach. For example, research is needed to understand the ecological impacts of floatovotaics or the best way to anchor them.
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