Floating Solar for Power Generation & Clean Water
Looking at Floating Solar and Our Sustainable Future
As energy costs rise and the threat of climate change looms ever larger, the interest in alternative sources of energy has increased. Solar power, known in the science community as photovoltaics, is a viable clean alternative to fossil fuels that is growing in popularity worldwide. And with floating solar comes more possibilities.
Most people are familiar with land-based solar panels. We see them on our neighbor’s homes, on roofs over parking lots, or spread over acres of open land. Less is known about water-based solar power options. Also called floating photovoltaics or FPV, floating solar power is an emerging technology within the industry.
Popularity of FPV is growing, particularly in urban settings where there is a shortage of land to sustain a large enough solar field to support the power needs of large populations, and rural areas where land-use regulations prevent the installation of land-based solar (Elliot).
Solar power is an excellent source of clean, renewable energy.
As nations worldwide strive to combat climate change, there has been a rush of research and technological advancements at all levels of the solar industry, from the structure of panels and energy output, to the platforms that support the panels and where those platforms can be placed.
Challenges to the integration of solar power
Few challenges to widespread use of solar technology remain. The technology already exists to begin the transition from fossil fuels to clean solar energy. Perhaps the biggest challenge is integrating renewable power technologies into the existing energy distribution system (Larson).
Shifting from a fossil fuel-based energy system to a system built around renewables will require a coordinated effort between energy producers, consumers, state and federal legislatures, and the scientific community (Kariuki).
A few technical challenges to the use of solar power are dust and debris collection on the panels, which blocks the sun and limits energy output, and damage from waves, weather, and human and/or wildlife interference, and perhaps most significantly, the lack of geography.
Solar power requires a lot of space. Particularly in urban areas, there is limited room for large-scale solar arrays. Some of this challenge may be alleviated by further technological advances that make solar panels more efficient. But even with highly efficient solar arrays, the space required to produce enough power to service major metropolitan areas is still vast.
Making the case for solar on water
The fact is, land is a limited resource. Once a structure is built, the land cannot be used for much else. Whereas land-based solar makes the land it’s on unusable for most other purposes, such as most agriculture, recreation, or wildlife habitat, water-based solar can be integrated into the existing ecosystem, and may even enhance the water it floats on.
Placing solar panels on water frees up land for other uses. For small island nations with limited available space for land-based solar or wind power, floating photovoltaics may be the only viable option (Solar Energy Research Institute).
Floating Photovoltaics (PV) are the future
Solar photovoltaics is one of the strategic renewable technologies needed to reach Paris climate goals. The technology is available now however there are obstacles to its large scale development. One of these obstacles is geographical. There is not enough space!
Land space may be limited, but 71 percent of the earth’s surface is water. Floating solar – also called floating photovoltaic, FPV, or floatovoltaic technology – is not yet in widespread use, but there are several major projects worldwide.
Innovators are making great strides towards utilizing static fresh water bodies with few waves such as man-made ponds or reservoirs, large, fresh water bodies with small to medium waves and water-depth variation such as lakes made by hydro-electric dams, near-shore seawater such as harbors, estuaries, and ports with medium waves, and even offshore seawater with high waves for power generation with varying levels of success.
The largest floating solar farms are in Asia, including:
Anhui Province, China. Lianghuai Mining Subsidence Solar Plant. The largest floating solar project in the world was built in the Yongqiao District of Suzhou City in China in a former coal mine pit that is now a reservoir (Kenning).
Deoku Reservoir, South Korea. The rotating solar arrays of the Deoku Reservoir floating solar project follow the sun’s movement throughout the day, which maximizes energy yields (Clover).
Banasura Sagar Reservoir, Kerala, India. The Banasura Sagar Solar Plant is the largest floating solar array in India. It covers 1.25 acres of water in a reservoir created by the Banasura Sagar Dam (KSEB).
Yamakura Reservoir, Chiba Prefecture, Japan. Japan’s largest floating solar project, located in the reservoir created by the Yamakura Dam, generates 13.7 megawatts of power (Kyocera).
Tengeh Reservoir, Singapore. Construction began in August 2020 on a 60 megawatt floating solar project in Tengeh Reservior. When completed, it will cover the area of approximately 45 football fields (Largue).
Sayreville, New Jersey. A wastewater retention pond in Sayerville, New Jersey is host to the the largest solar array in the United States. The solar project supplies power to the city’s wastewater treatment plant (Ludt).
Far Niente Winery, Napa Valley, California. The first floating solar project developed in the world supplies power to a vineyard in Napa Valley. Rather than sacrifice valuable land on which to grow grapes, the winery opted to use a pond on the property to float it’s solar array (Kimmel).
The Advantages of Floating Solar
The pros of floating solar power far outweighs the cons, which are increasingly easy to mitigate. Floating solar makes use of otherwise unused space, and many of the problems associated with land-based solar are largely eliminated when solar arrays are instead floated on water.
Water-based solar tends to have lower operating temperatures, which makes the panels more efficient, producing greater energy productivity. Solar panels and their platforms shade the water, which slows evaporation. This is particularly beneficial to high drought areas such as the American southwest. (Spencer, et. al.)
Human population tends to congregate around water sources. Therefore, floating solar brings clean energy to the areas with the highest power consumption, such as urban and water recreation areas. Alternatively, floating solar can also be used in remote locations that are far from the energy grid.
Positioning solar arrays on water also reduces damage from wildlife and human interference. The problem of dust collection on the panels is less on the water than it is on land, and since water surfaces are relatively open, less shadows are cast upon the panels (Huang). Thus, floating solar has the potential for greater output of energy than land-based solar.
Agriculture may be uniquely positioned to benefit from floating solar. A great deal of power is needed to fuel a farm or ranch, and farmers rely on irrigation to water their crops. Irrigation canals and agricultural reservoirs are ideal locations to house FPV, due to the relative stability of the water’s surface.
Because irrigation canals and reservoirs tend to be shallow and slow-moving, much water is lost to evaporation, and waterways are prone to algae growth, which creates eutrophication of the water source. Floating solar provides low-cost energy to farmers without using any of their valuable land space, reduces evaporation by shading the water, and depending on the design and associated technology used can minimize algae growth (Hoffacker, et. al).
Floating solar arrays in Asia have already successfully integrated power generation with habitat cultivation, and fishing for recreation and profit. With low operations and maintenance costs, and limited impact on wildlife both above and below the surface of the water, floating solar arrays are a sensible choice for clean, renewable energy (Bellini).
There is increasing evidence that floating solar may actually improve the water. The Lianghuai Mining Subsidence Solar Plant in Anhui Province, China was floated over a mining site that would have been contaminated and unusable. By shading the water, the Anhui Province solar project prevents algae growth and oxidation, as well as conserves water by reducing evaporation (Gleeson).
Because water is constantly moving, floating solar has minimal environmental impact. The panels and their platforms simply become a part of the natural environment. The platforms attract fish, and provide shelter and opportunities for marine life.
The Disadvantages, or Challenges Facing Floating Solar
Any floating solar application will need to survive nature’s onslaught, such as hurricane-force winds in the Gulf of Mexico, snow dumps in the ocean off the coast of Alaska, tornadoes in the central United States, typhoons in Singapore, and days-long windstorms in coastal areas.
In the case of floating PV, which must float on the water’s surface, installation may face challenges due to platforms moving or rotating when wind blows or waves hit. For the system to achieve maximum efficiency, the mooring system must completely stabilize the buoyant structure of the floating PV system on the water’s surface.
Careful considerations must be made in areas with fluctuating water levels, especially in tropical locales where heavy rain can cause water to rise several feet in minutes, as well as the changing seasons in northern areas (Chester). Research still needs to be done to measure the impact of repeated freezing and thawing on the stability and proper functioning of solar panels and their platforms (Jeung).
Because floating photovoltaics is such a young technology, there are still a lot of unknowns in the areas of innovation. Now that all the technology exists to implement large-scale floating solar projects, the only way further progress will be made is to actually build them, test them, and improve upon them based on real-world applications.
Field studies are necessary to determine what will become standard in the industry, and FPV systems must be customized according to the unique ecosystems and climates in which they are installed. As with all energy systems, there are a lot of moving parts to consider, each with their own subset of experts in multiple different disciplines of study and development.
Research is ongoing at all levels of floating solar technology, including:
- Determining the best material for the PV collection panel.
- Design and materials of platforms, such as concrete, steel, plastic, styrofoam, etc.
- Anchoring, which must be suited for tidal fluctuations, water depths, etc.
- Batteries, including expanding storage capacity and longevity with minimal maintenance.
- Weatherproofing of the inverter, a challenging aspect since the inverter contains electrical elements susceptible to moisture and corrosion.
- Protection of the panels and platforms from wind, waves, wildlife, and human interference.
- Habitat preservation and restoration.
Different designs are currently in use, and long-term studies are still in progress. There are important questions as of yet unanswered by widespread research regarding ecological impact on aquatic life, waterfowl habitat, and environmental impact.
Studies have shown conflicting results as to the impact FPV has on the temperature of water. Some evidence suggests that floating solar panels can heat the surrounding water, which can disrupt the ecosystem. However, other studies have determined that FPV installations result in a decrease in water temperatures. Further study is required to determine what causes this discrepancy – is it due to the specific type of platform used, or does it vary by climate, water depth, or other variables?
Many such questions have been answered by innovators of products that can be synergized with FPV. As the industry continues to grow, these innovators will continue to contribute to the broader knowledge of floating solar. As with any complex industry, advancements will be made as creatives from complementary fields join forces to continually improve upon the design, function, and efficiency of the technology.
A well-designed floating photovoltaics project can do more than simply generate power.
The future of energy production must consider not only power output, but environmental impact. Floating photovoltaics have increased impact by cleaning waterways while generating clean energy.
Water as a source of greenhouse gas emissions has not received the attention it deserves. Methane – the leading culprit in global warming – is produced by eutrophic lakes. A 2018 study indicates that even “moderate” eutrophication can increase greenhouse gas effects by 5-40 percent (DelSontro). The increase in harmful algae blooms is clear indication that eutrophication is far beyond “moderate.” (https://www.waterrr.co/climate-adaptation.html)
Preventing harmful algae blooms and resulting greenhouse gas emissions, provides predictable water and air quality improvement. The solar industry is under increasing pressure to quantify the benefits of FPV over other energy sources. Without quantifiable data that demonstrates the substantial benefits floating solar provides to the surrounding ecosystem, it can be challenging to meet the requirements for financial incentives, such as carbon credits.
Alternative energy companies have turned to large waterways—which are often plagued by huge unrelated water-health problems, most notably Harmful Algae Blooms (HABs)—as a place to deploy their collection panels.
BioHaven products address major floating solar obstacles
Whether set on an inland lake, in coastal waters, or out at sea, some of the biggest challenges faced by floating solar have to do with the ability of the floating structure to withstand wind and waves and to remain in place.
Solar BioHaven introduces platforms that support massive arrays of solar panels to generate power that provide clean, renewable, alternative energy to electrical grids, and also mitigates HABs in the waterway.
Consider the parallel challenges towards reaching climate goals: greenhouse gas emissions and algae-plagued waterways.
Mitigating the barriers to floating photovoltaics is vital to boost deployment and bring socio-economic benefits as well as regional benefits.
It’s time to accelerate solar pv deployment on waterways
Our platform is engineered for resilience and longevity. Unlike typical pontoon floats, a solar platform of BioHaven Floating Islands works to eradicate HABs, while the mounted solar provides power and income generation.
The BioHaven Solar Platform is a Double-Duty Platform.
The PV (photovoltaic) panels and the floating island can be sized appropriately to generate solar power for an entire community, to use or sell back to the grid. BioHaven Floating Islands also provide real estate for the microscopic life forms that clean up water and resurrect the food web. As soon as an island is placed in a water body, biofilm starts to grow around and through it, reaching every fiber and crevice within the island, turning into a natural cleaning system. Water clarity improves. They make use of available water space and clean the water at the same time.
BioHaven Solar Platforms are Stable and Resilient
Resilient floating solar platform provides stable support for the generation of clean, reliable energy for communities.
Buoyancy is adjustable to 60lbs per square foot to support the heaviest loads
Optional addition of hyper-accumulator plants accelerate the water quality improvements without occluding the solar panels
BioHaven Floating Islands have withstood hurricane-force winds in the Gulf of Mexico, 48-inch snow dumps in the ocean off the coast of Alaska, a tornado in Montana, a typhoon in Singapore, and a two-day windstorm in Oregon.
Recycled Non-BPA, PET matrix, heavily “armored,” provides resistance to waterfowl, promotes growth of beneficial biology that cleans water naturally, does not leach or lose plastic in the water, and may even uptake toxic microplastics from the water.
Other Reasons to Choose BioHaven Solar Platforms
Early in Floating Island International’s (FII) history, a commercialization grant was awarded by the Montana Department of Commerce to study the impact of BioHaven matrix on nutrient removal. The results were astounding. They convinced us that even without plants, the matrix provides enough surface area to make a significant reduction in phosphorus, nitrogen and ammonia, all of which contribute to Harmful Algae Blooms. The literature supporting biofilm as a primary nutrient-removal pathway is extensive.
The BioHaven matrix has been upgraded many times since that study was published to make it more robust and resilient to climate and weather impacts, while maintaining its performance capacity. Most significant have been the improvements in UV-resistance, tensile strength and armoring. We project a 60-year design life for today’s BioHavens (2020).
Today we have single-module, seamless, floating islands of about 95 square feet that can support 2,500 pounds of negative buoyancy. These can be attached together to form custom-size platforms.
A saturated BioHaven will weigh twenty times as much as a similar footprint of pontoon and will accumulate mass as it ages. This allows a well-anchored BioHaven platform to maintain a stationary position in the face of hurricane-force winds. Massive waves hit them, and their energy is sparged and dispersed within the water-damping matrix. Wind chop is attenuated.
60+ years. Advances in construction methods include a tough coating of “armor” that protects the outer surfaces from UV and environmental damage. This is the same material that protects the insides of municipal water inventory tanks.
These islands, framed together as massive archipelagos, can support seven or eight times their square footage of solar panels. The largest existing BioHaven in North America is a 40,000 square foot island that supports 900 tons of gravel.
For each square foot of BioHaven® floating island, about 12 recycled PET bottles have been transformed into the matrix. The internal viscosity (IV) is extremely high and superior to most virgin PET.
If BioHaven Floating Islands provided no additional benefits, they would still be far superior to pontoons. But they do. The BioHaven matrix performs like a wetland, its intricate surface area supporting biofilm growth that filters water and removes contaminants. It is also an excellent growing medium for deep-rooted plants that accelerate remediation.
Large BioHavens fix large lakes
Nutrient removal is essential for preventing harmful blooms of algae and Golden Algae. BioHaven matrix supports the growth of biofilm that is the optimum pathway for biological removal of excess nutrients in water, even without plants. With the addition of plants, the efficacy is multiplied. Low-growing hyperaccumulator plants accelerate the water quality improvement even further.
A lot of BioHaven surface area is required to fix a very large lake, and installing this could be cost-prohibitive. But installing a BioHaven solar platform that happens to fix a large lake is affordable.
Alternative energy companies have recently turned to waterways as a place to deploy their collection panels. But a weak spot in floating solar platforms is the flotation itself. A manufactured platform is supported by pontoons. Pontoons are buoyant, but also exceptionally light and unstable, tossed about easily by forces of nature — wind and waves — a roughing-up that is not good for the delicate photovoltaic technologies that reside on the islands.
A BioHaven solar platform can be used to cut operating costs.
Customizable solar arrays can be mounted on large platforms to deliver power for other uses. For example, wastewater lagoons can derive enough power from solar on their islands to run their aerators, usually the most costly of their operating expenses.
Governmental Incentive Programs May be Available.
You may be able to fund the purchase and installation of BioHaven Floating Solar through Government Incentive Programs. These are some of the programs we are aware of in mid-2020:
- Database of State Incentives for Renewables and Efficiency
- Renewable Energy Systems and Energy Efficiency Improvement Program
- Energy Efficiency and Conservation Loan Program
- For HAB management:
- Federal Clean Water Act Section 319(h) Grants
- National Water Quality Initiative
- Clean Water State Revolving Fund
- Urban Waters Small Grants
You may be able to earn nutrient credits:
- State Trading Programs
EPA – Water Quality Trading
Although funding to fix water quality is inconsistent, many states offer powerful incentives to produce solar energy. Many of the states with the best incentive programs also have the biggest issues with HABs. Nutrient credits may also be available to you as your water quality improves after installation.
Solar BioHaven for Power Generation & Clean Water
- alternative energy generated close to delivery areas = safer (no above-ground wires) and less expensive
Solar BioHaven for Clean Water Powered by Alternative Energy
- alternative energy generated by solar on the floating island power nano-bubblers and eliminate blue-green and other toxic algae fast
- power up nature’s own re-generation cycles with nature’s own energy source