The idea of floating solar panels on water has barely gotten off the ground and it is already catching on across the planet. In particular, decarbonizers are excited by the potential to use the large reservoirs at existing hydropower facilities for new solar arrays instead of using up precious land. That’s a significant sustainability win-win, and a gigantic new Masdar-backed project in Indonesia could serve as a model for others to follow.
World’s Largest Floating Solar Power Plant
The plans for the world’s largest floating solar power plant illustrate how quickly the floating solar field can grow. The project is aimed at expanding an existing 145-megawatt (AC) floating solar array at the Cirata hydropower reservoir in West Java, Indonesia, to reach a total of up to 500 megawatts.
The existing array went online and was proclaimed successful just last month. Evidently Masdar and the state-owned Indonesian utility PLN (Nusantara Power) already liked what they saw, because they used the occasion of COP 28 to announce the new expansion on December 3.
If Masdar rings a bell, that would be the Abu Dhabi Future Energy Company, which bills itself as the United Arab Emirates’s “clean energy champion and one of the fastest growing companies in the world, advancing the development and deployment of renewable energy and green hydrogen technologies to address global sustainability challenges.”
Masdar launched in 2006 and CleanTechnica has covered the company’s renewable energy projects over the years, including an in-person visit to its Masdar City clean tech showcase back in 2016 during the Abu Dhabi Sustainability Week, featuring on-site solar power among many other energy transition tools (more recent CleanTechnica Masdar coverage is here.
At the same visit we took a brief note of Abu Dhabi’s interest in nuclear energy, so it’s no surprise to see nuclear energy playing a central role in COP 28, which is being hosted by the UAE.
For the record, Masdar is a joint project of the ADNOC (the Abu Dhabi National Oil Company (ADNOC)) along with the, Mubadala Investment Company (Mubadala), and Abu Dhabi National Energy Company.
Floating Solar Is More Complicated Than It Looks
Over its relatively brief lifespan, the floating solar field has already established a roster of substantial benefits over and above generating clean kilowatts.
The land conservation angle is the big one, but floating solar stakeholders also point out that shade from the solar panels helps reduce evaporation and conserve water. Solar-shaded reservoirs and irrigation canals may also be less susceptible to toxic algae blooms.
The benefits also circle back to impact solar cell conversion efficiency, which can be improved by the cooling effect of water.
On the power generation side, co-locating solar arrays at existing hydropower plants enables solar stakeholders to take advantage of existing power lines and ground transportation infrastructure.
Water has its downsides, though. The imperative to avoid corrosion is a big one overall, and the unique environment of hydropower reservoirs can complicate matters much farther as water levels rise and fall.
The Chinese floating solar firm Sungrow FPV constructed the existing solar array at Cirata, and they had plenty to say about the challenges of placing solar panels there.
The Cirata project is “the largest floating solar project in a hydropower reservoir with a water depth of 100 meters, water level fluctuation of 18 meters, and a 50-meter difference in water bottom elevation, the company observed in a press release last November. The company cited the “intricate underwater terrain” as posing a particular challenge for the anchoring system.
“The system solution team from Sungrow Floating PV has developed high-load-bearing anchor blocks tailored to the specific geological conditions of the project site,” Sungrow explained. “These innovative anchor blocks enhance load-bearing capacity, effectively addressing challenges such as block slippage and significantly improving construction efficiency.”
“Through precise and reliable computational simulations, each anchor block is meticulously validated, facilitating the overall anchoring system design for the entire project,” the company added, noting that the tailor-made approach provides for a more efficient use of the available surface.
The surface availability angle is an especially important consideration for hydropower reservoirs that double as nature habitats and recreation areas, as many do. Squeezing solar panels into the picture can be a challenge without running afoul of other stakeholders.
More Green Hydrogen, Too
As described in the November press release, Sungrow plans to “support the development of the clean energy industry in countries and regions participating in the Belt and Road Initiative.”
That covers a lot of territory. As of October, the sprawling China-led infrastructure development plan has reportedly gathered 152 countries and 32 international organizations onto its roster of projects. The application of lessons learned at Cirata could have widespread impact on other floating solar projects under the Belt and Road umbrella.
On their parts, Masdar and PLN are also not stopping at Cirata. In their joint December 3 announcement, the two companies also announced green hydrogen projects to go along with their floating solar plans.
“The companies also agreed to explore renewable energy options around the world and the prospect of developing green hydrogen, which has huge potential for decarbonizing hard-to-abate industries, including steelmaking, construction, transportation, and aviation,” Masdar and PLN state.
Floating Solar, Green Hydrogen, And The Energy-Water Nexus
“With abundant solar resources, the UAE and Indonesia are in prime position to become green hydrogen production hubs,” the two companies continued. That brings to mind some interesting opportunities in the floating solar field related to green hydrogen.
Green hydrogen can be produced from water and other renewable resources. Much of the activity today is focused on electrolysis, which pushes hydrogen gas from water with the help of an electrical current and a catalyst.
Photocatalysis (also called the “artificial leaf” or photoelectrochemical cell) is another approach gaining attention. Both systems typically require purified water to prevent fouling and damage to the equipment. As a near-term solution , the US Department of Energy is among those promoting the development of new low-cost water pre-treatment systems for green hydrogen.
Meanwhile, work is continuing apace on more sophisticated systems that can push hydrogen directly from seawater and other unpurified sources.
In the latest development on that score, in November a team of researchers at the University of Cambridge published their findings on a new floating photovoltaic device that produces purified water in addition to green hydrogen.
Their floating solar device deploys a water-repellent nanostructured carbon mesh to help keep the photovoltaic layer afloat, while also protecting it from any impurities in the water below.
The PV part of the solar device is designed to absorb UV light, to power the electrolysis part of the operation. Meanwhile, other parts of the light spectrum pass through to the bottom layer, which produces pure vaporized water for electrolysis.
