FLOATING SOLAR WORLDWIDE

- ADVANTAGES OF SOLAR IN RESERVOIRS BEHIND HYDROPOWER DAMS

Floating Photo-Voltaic Solar-Power installations (FPV or Floatovoltaics) associated with hydropower dams are becoming increasingly popular worldwide. Currently, FPV is primarily installed in Asia, California, and other areas where land prices are high, offsetting the additional cost of higher installation and maintenance (20-40% more than solar on land) and likely shorter lifespan (due to potential corrosion, more difficulty reaching the panels for maintenance, waterfowl and wildlife impacts, fouling, and wave wear).

When installed in hydropower dam backwaters, FPV can take advantage of existing high-power electric transmission lines and even permit pump-back "water battery" storage of renewables this way. Complimenting hydropower facilities, FPV may provide higher reliability during droughts or periods of low flow to more consistently generate power year-round, while allowing hydropower to serve for peaking, while the solar may provide base load advantages to keep more water behind the dam for longer.

If the installation is large enough - recommendations span from 10-40% of the surface area of the water body - the problem of evaporation can be significantly diminished, both due to shading and the decrease in wind fetch. Other potential benefits are reduced algae growth and toxic cyanobacteria blooms, fish habitat and refuge from fisherman to grow larger or spawn, and local economic development with enhanced electricity availability. Colocating solar on reservoirs provides the opportunity to use the new energy for improved water supply, distribution, water recovery / water recycling, and to setup water quality and lake enhancement features.

Shoreline, bay area, and offshore FPV may be used for desalination and co-location with off-shore wind to improve project reliability and cost-effectiveness. Integrated with Aquifer Storage and Recovery (ASR), FPV can provide energy for pumping, treatment, and distribution to reduce salt-water intrusion and improve long-term groundwater reliability.

Although not many of the largest installations may serve these purposes or even be associated with hydropower or manmade reservoirs, it's informative to study them. Here are a few of the largest floating solar installations in the world:

1. Anhui Fuyang Southern Wind-solar-storage Base floating PV power station (China):
• Solar Capacity: 650 MW (175,000 homes)
• Eastern Construction Management Department of the Three Gorges Energy Department - 2023
• Completed in 2023, this 650 MW floating solar project is located in Fuyang City of east China's Anhui Province, in a flooded area once used for coal mining of 867 hectares in the Yangtze River Delta region. Along with a 550 MW wind power project, a 300 MW/600 MWh storage power project permits the renewable energy to be partially saved for peak demand periods (source).
2. Omkareshwar Dam Floating Solar Energy Project (India):
• Solar Capacity: Planned to be 600 MW
• MP Power Management Company Ltd / Rewa Ultra Mega Solar Limited (RUMSL) - 2023 block 1, 273 MW
• Under construction at the Omkareshwar Dam on the Narmada River, the first 273 MW block was installed in late 2023, it is anticipated to reduce water evaporation and produce up to 21% more energy than ground mounted solar due to cooling and reflection. (source).
3. Huaneng Dezhou Dingzhuang Reservoir Solar PV Park (China):
• Solar Capacity: 320 MW
• Huaneng Power International (HPI) - 2020
• This project is connected to battery storage and a wind farm! The facility can generate 550 million kWh of electricity per year! It is a platform solar construction, all in one piece. (source).
4. Three Gorges New Energy Floating Solar Farm (China):
• Solar Capacity: 150 MW
• Three Gorges New Energy Company / Sungrow (inverter specialists) - 2018
• Another significant project in Anhir Province, China, this floating solar farm on tailwaters behind the Three Gorges SuperDam provide local power, while reducing land pressure and curtailing when the source is not close enough to users. (source).
5. Sihwa Lake Tidal Power Station Floating Solar Farm Phase 3 (South Korea):
• Solar Capacity: 102.5 megawatt (MW)
• Korea Western Power Co - 2020
• Sihwa Lake is a 43.8 km2 artificial lake constructed as a land reclamation project by the South Korean Government in 1994, using a 12.7 km long seawall at Gyeonggi Bay that produces TIDAL POWER. In phase III, a floating solar farm was added to provide enough additional energy to power about 35,000 households. (source).
6. Tengeh Reservoir Floating Solar Farm (Singapore):
• Solar Capacity: 60 MW
• Singapore PUB / Sembcorp - 2018
• The 60MW Tengeh Reservoir project covers 45 hectares on 10 floating islands, covering one-third of the reservoir's surface. It powers five local water treatment plants and the Marina Barrage - producing enough equivalent energy to power about 7,000 cars. (source).
7. Sirindhorn Dam Floating Solar Farm (Thailand):
• Solar Capacity: 45 MW
• Electricity Generating Authority of Thailand (EGAT) - 2021
• Situated on the Lam Dom Noi River, Ubon Ratchathani Province, this project generates solar power throughout the day and then hydropower at night or peak demand periods, allowing solar and hydro to fully compliment one another as envisioned! This increases the overall stability and reliability of systems power, using AI to continually improve operations of these complexities. (source).
8. Hapcheon Dam Floating Solar Power Plant (South Korea):
• Solar Capacity: 41 megawatts (MW)
• K-water (the Korea Water Resources Institute)  / Q Cells (Poseidon Edition Solar Panels for high temp and humidity) - 2021
• Located at the Hapcheon Dam, the DC to AC inverters are mounted on a floating platform gathered by combiner boxes. It produces enough solar electricity to meet the annual power needs of 60,000 people. As shown in the picture at the top of this article, the community chose to structure the panels in islands shaped as blossoms to be more visually appealing. What's more, many elderly invested in the development, realizing gains of about 10% annually! (source, source2).
9. Yamakura Dam Floating Solar Power Plant (Japan):
• Solar Capacity: 13.7 MW
• Ciel & Terre (using its internationally installed Hydrelio modular system) - 2018, Rebuilt in 2021
• Located on the Yamakura Dam reservoir in Chiba, the original monolithic form was redesigned in 2021 into individual sections after just 7 of 420 bolts gave way in the terrible 2019 Typhoon Faxai causing the structure to become badly damaged, demonstrating the risk to FPV in extreme weather (source).
10. Sibleco Schansheide Sand Quarry Floating Solar Farm (Belgium):
• Solar Capacity: 7.0 MW (17,250 Solar Panels, 6.5 MWh/yr, 2,000 homes)
• Sibleco, LRM, Luminus, and Machiels - 2020
• Located on a water treatment plant’s reservoir, it contributes to Belgium’s renewable energy mix (source, source2).

These floating solar installations demonstrate the potential of utilizing unoccupied bodies of water for renewable energy production, especially in densely populated regions with limited available land, while taking advantage of the benefits of renewable energy co-location and opportunities to enhance water supply / quality with additional energy resources.