Floatovoltaics are photovoltaic solar panel arrays installed on bodies of water like reservoirs and water treatment plants. These floating solar farms are an emerging niche within the renewable energy industry. The National Renewable Energy Laboratory estimated that floatovoltaics installed on just a quarter of the United States’ manmade reservoirs could generate at least ten percent of U.S. energy needs.
Land is a scarce resource that many industries like housing, agriculture, and renewable energy projects must compete over. While solar panels continue to decline in costs, this progress is offset partially by the rising costs of renting or purchasing land. Floatovoltaics reduce the need for additional land or rooftop space by leveraging bodies of water.
Floatovoltaics offer many attractive benefits that make them an exciting growth market within renewable energy. In addition to reducing land cost requirements, floatovoltaics may generate power more efficiently, limit water evaporation, and reduce harmful algae growth. By reducing costs and improving the environment, floating solar farms may play an important part in the global transition to net-zero emissions.
Solar Panel Adoptions Barriers
Since 2010, the price of solar power has fallen by over 80% due to scales of economy and technological improvements. Now, solar power cost less than fossil fuels and continues to benefit from innovation and scale. While the outlook is extremely positive, there are still some barriers that create friction for mass adoption.
Traditional solar farms are land intensive and require more space on a per-watt basis than fossil fuels. Each panel in a solar farm also requires a certain amount of spacing for tilting to optimize for energy generation. This leads traditional solar farms to compete with other necessities like housing and agriculture for valuable land.
Deploying renewable energy projects on public land remains a goal of the Biden administration. In June, the Interior Department announced a rate reduction policy for solar and wind energy that reduced the rates and fees developers must pay to the government. This provides a strong incentive for developers to establish solar and wind farms on public lands.
While the implemented rate reduction makes developing on public land more attractive, there still remain additional costs and tradeoffs. Traditional solar farms may incur soil treatment costs, regulations for structures, and public opposition. Sonoma County, known for its beautiful rolling hills, did not want to cover them with solar panels.
Solar panels and solar farms’ energy generation is temperature dependent. While the temperature does not affect the amount of solar energy a panel receives, it does affect how much power a solar panel may generate. This effect leads to lower efficiency for solar farms in geographies with warmer climates.
Solar panels are filled with electrons that are excited by sunlight hitting the photovoltaic cells. The difference between the energy of the electrons at rest and excited by the sun generates the voltage that is captured as power. The lower the rest energy, the more energy the solar panel may create.
As the temperature of a solar panel increases, so does the temperature of the resting state of the electrons in the cells. This reduces the difference between the resting and excited states which lowers the energy generated by the solar panel. In order to optimize for power generation, solar farms attempt to manage the temperature of their panels.
Renewable energy is necessary to phase out fossil fuels and slow the effects of global warming. While solar and wind farms are leading the transition, there are open questions about the environmental costs of these projects. Many ecosystems that are ideal for solar farm development are extremely fragile and may be damaged by solar projects.
Deserts are a common development site for solar farms because of the sun exposure and open land. While these may be ideal conditions for developers, many environmentalists argue that this could irreparably damage an already fragile desert ecosystem. Solar farms displace native species and potentially destroy thousands of native plant species.
In the Mojave Desert, Yellow Pine is a 3,000-acre solar farm that provides 500 megawatts of electricity to 100,000 homes in California. The project required scientists to relocate over 100 federally protected desert tortoises of which at least 30 died. As solar continues to gain adoption, projects must balance the environmental impact with the importance of renewable energy.
Floatovoltaics Reduce Adoption Barriers
Floatovoltaics are solar panels that are affixed to a floating platform. This platform is equipped with a mooring and anchoring system that prevents drifting and enables the panels to optimally orient towards the sun. By floating on top of manmade bodies of water, floatovoltaics reduce solar adoption barriers and present an exciting emerging market in renewable energy.
Bodies of Water
Solar farms compete for land with agriculture, infrastructure, and housing. They may also require up to 20 times more land than fossil fuel power plants to generate a gigawatt of electricity. While land is a scarce resource, there are over 24,000 manmade reservoirs in the United States where floatovoltaics may be deployed.
Floatovoltaics may be deployed on these reservoirs which include wastewater treatment plants, drinking water reservoirs, and hydropower plants. This frees up valuable and expensive land for other projects like housing, agriculture, and infrastructure. It may also address many of the ecosystem concerns that environmentalists currently have about solar farms.
The United States Army recently deployed the largest floating solar farm in the Southeastern U.S. and the first installation by the Department of Defense. The 1.1-megawatt system sits atop the Big Muddy Lake at Fort Bragg in North Carolina and helps supply power to the largest domestic military base. This development signals the growing importance floatovoltaics will play as renewable adoption continues to accelerate.
Floatovoltaics generate power more efficiently than solar panels deployed on land. Water provides a cooling effect on floatovoltaics that reduces the resting temperature of electrons in the solar cells. This enables floatovoltaics to capture more power when exposed to sunlight.
In addition to generating power more efficiently, floatovoltaics also may lower deployment costs. When floatovoltaics are deployed on hydroelectric farms, they can use the existing power infrastructure for transmitting and storing energy. This can significantly reduce costs and offset any additional ones incurred for deploying floating solar panels.
A floating solar plant in Jamestown, Australia, generates up to 57 percent more power than a similar rooftop solar farm and up to 20 percent more energy than a land-based array. While floatovoltaics cost more than land-based solar panels, the costs are more than offset by the improved efficiencies. These benefits illustrate why floatovoltaics may become a high-growth area in the solar panel industry.
Floatovoltaics placed on manmade bodies of water reduce ecosystem damage and mitigate other environmental factors like evaporation. In many areas susceptible to droughts, floatovoltaics placed on reservoirs and hydroelectric plants can reduce evaporation. Deployment on these manmade bodies of water also prevents damage to any fragile ecosystems like deserts.
Covering a reservoir or hydroelectric plant with floatovoltaics effectively minimizes the natural effect of evaporation. This preserves water reserves that are especially important during droughts. It also maintains the water available to generate hydroelectric power and reduces some of the variability of hydroelectric power generation.
Floatovoltaics may also reduce the cost of water treatment by reducing the amount of sunlight that reaches a body of water. This can restrict the growth of algae which raises the cost of water treatment for water treatment plants. Minimizing evaporation, preserving fragile ecosystems, and reducing water treatment costs make floatovoltaics one of the most attractive options for renewable energy.
The Emerging Floatovoltaic Market
Floatovoltaics make up two percent of all solar installations in the United States. This nascent market presents immense benefits that improve efficiencies, reduce environmental impact, and free up valuable land for other development. As renewable energy continues to see rapid adoption, floatovoltaics will become an exciting emerging market.
The United States Amry launching a 1.1-megawatt floatovoltaic system illustrates the confidence the government has in floating solar farms. In addition to the U.S. Army, states like California are experimenting with floatovoltaics to generate solar power while improving drought preparedness by reducing evaporation. New Jersey is also investing in the largest floating solar array in the United States that spans 16,000 panels and should generate up to 8.9 megawatts.
While floatovoltaic adoption is relatively slow, solar panel costs and the two-year solar tariff suspension make this market prime for growth. These cost reductions and cutting out land renting expenses make floatovoltaic solar energy highly attractive. By minimizing these costs, floatovoltaics may produce more energy at a lower price than their land-based counterparts.
The cost benefits of floatovoltaics may place more downward pressure on energy prices in the future. Generating energy more efficiently and at a lower cost will enable floating solar panel farms to sell power at lower prices while maintaining competitive margins. The economic and environmental benefits may act as a catalyst for domestic adoption.
Within the United States, there are over 24,000 manmade bodies of water. Deploying floatovoltaic systems across them would conservatively generate up at least 10 percent of United States energy needs. This potential alone illustrates the importance of floatovoltaics to the net-zero, renewable energy future.