Earlier this month, the US Army launched a large floating solar array at Camp Mackall on Fort Bragg in North Carolina— the country’s largest domestic military base. This launch marks a critical moment for floating photovoltaics (FPVs) which have yet to attract mainstream attention in the USA.
Two-thirds of the planet’s surface is covered by water, but despite their immense promise, these “floatovoltaics”, FPVs, only make up 2 percent of all domestic solar installations. Floatovoltics have the potential to solve several of the problems plaguing conventional solar energy: exclusive land use, energy distribution, and heat dispersion. The promising tech may also help with hydrological regulation in canals, reservoirs, and draught-threatened natural bodies of water.
While solar is the cheapest renewable electricity resource, it has less energy density than fossil fuels and is more land intensive. On average, traditional solar farms require more space per watt than fossil fuels. Natural gas, for instance, is approximately 80 times more power-dense than solar. This is especially challenging because solar developers often face opposition from residents who see sprawling farms as a blight—citing reasons ranging from decreasing home values to habitat harm to loss of arable land.
However, floatovoltaics are built to float on a body of water reducing the land requirement necessary to produce renewable energy. Project designers can make FPVs in various shapes to fit the location. Suitable bodies of water include on-shore ponds, lakes, reservoirs, dams, or off-shore waters. This practice can reduce land sparing and free up space for agriculture, infrastructure, and other needs.
Floatovoltaics also have the advantage of increased efficiency not only over land installations but as a multiplier for hydropower. When installed on hydroelectric dam reservoirs, floatovoltaics limit evaporation, preserving more water for electricity. Installations placed on hydropower reservoirs are cost-effective too as they can connect to existing power grid links.
The G-7 industrial democracies and OECD countries have prioritized greenhouse gas reduction. Last year, the Biden Administration set an ambitious goal of reaching a carbon-pollution-free power sector by 2035 with a significant reliance on solar energy. With recent shocks threatening to derail the best-laid plans, floatovoltaics offer a welcome means of boosting a sensible renewable energy agenda despite higher upfront costs.
While FPV’s discreet charms are not evident in the USA, in East Asia, where most available land for large-scale solar farms is already allocated for buildings, industry, or agriculture, floatovoltaics are poised to transform energy portfolios. In 2007, the first pilot FPV plant was installed in Aichi Prefecture, Japan. China currently leads FPV installations, with India and South Korea following closely behind. Although Japan has the largest number of finished FPV projects of any country, Indonesia, Vietnam, Thailand, and Malaysia are also emerging markets for FPV installations. The Asian Development Bank (ADB) has been a leading institution in expanding technology. Its 2018 FPV regional development project has already strengthened East Asian FPV usage.
Despite the enthusiasm, FPV comes with barriers. While FPV plants are intended to last up to 25 to 30 years, equipment corrosion can reduce their durability and require more maintenance, especially in waters with high salt levels. FPVs are also more capital intensive as the FPV initial instillation cost rises between 10 and 15 percent compared to ground photovoltaics. FPVs also still suffer from many of the intermittency issues that land installations suffer; energy only when the sun is out and disparate timing in stressing power grids.
Developments in battery technology are both opportunities and bottlenecks for future FPV development. Any floating solar installation, especially those used by the US military, must possess ample storage capacity. Solar energy generation will increase if manufacturers can develop adequate storage technology. American companies such as Tesla
The world’s current reliance on land-based solar power to reach its climate goals puts American energy security at risk because China is the largest producer of solar panels. However, the security of FPV supply chains presents an investment opportunity for reciprocal investment and advancement not prone to Chinese pressure.
Manufacturers of floating solar in countries such as Singapore, South Korea, Indonesia, and Japan can replace Chinese imports and benefit from American “friendshoring”, helping to bolster the security of American supply chains. Companies like Hanwha Solutions of Korea and Kyocera of Japan are poised to step in— not to mention the largest participant in the floating solar industry, Ciel & Tierre International of France, the United States’ oldest ally. The United States can also utilize its competitive advantage and help bypass China’s current solar power advantage.
The future of sustainable energy is likely to be increasingly affected by environmental constraints, especially limits on land use. Fields of solar panels and forests of wind farms have a host of scientific, logistical, and political hurdles. Floatovoltaics are promising and worthwhile because they are piggybacking on existing water surfaces that are not otherwise utilized.
FPVs solve issues in the supply chain, land usage, and hydraulic regulation without attracting so much unwarranted optimism or visceral opposition. Floatovoltaics are one of the most promising and practical green energy technologies in that the US has a competitive edge that can be practically scaled up. FPVs must be recognized as a critical element of America’s required energy transformation.
With assistance from Breanna Nierlich and Sarah Shinton