Solar farm on the ocean outperforms land-based solar in Taiwan

The ocean could be the next frontier for the world’s rapidly expanding solar energy industry. That’s the finding of a study showing a floating solar farm off the coast of Taiwan produces more electricity and more profit than a nearby solar farm on land. Taiwan is roughly the same size as the Netherlands, but it is mostly mountainous and has 5 million more people, meaning open space is scarce.

As a potential solution, Chenya Energy built a 181-megawatt offshore floating photovoltaic (OFPV) project – sometimes called a “floatovoltaic” – on 1.8 square kilometres of water in the protected bay of an industrial park in western Taiwan in 2020-21. The year before, the Taiwan Power Company had constructed a 100-megawatt land-based photovoltaic (LPV) project on 1.4 square kilometres near the bay, providing an ideal comparison once researchers excluded the additional 81 megawatts of capacity at the floating solar installation. Pound-for-pound, the floating solar produces 12 per cent more electricity than the land-based solar, they found. Even though it has slightly higher operations and maintenance costs, it generates 11 per cent net profit, as opposed to 8 per cent for the land-based solar. “Installing the PV system on the sea, on water, is more difficult than installing the PV system on the ground,” says lead author Ching-Feng Chen at the National Taipei University of Technology. But “for the carbon reduction, emissions reduction, OFPV is much better than LPV”. More than 1100 floating solar systems have been built on lakes and reservoirs, mostly in China and other densely populated Asian countries. While the main attraction is that they don’t take land away from farming or development, they can also generate up to 20 per cent more electricity than land-based systems, although that number varies widely from site to site. The improved performance comes from the fact that solar panel efficiency declines as temperatures rise, and because conditions are typically 2-3°C cooler over water than over land. The stronger winds experienced over large bodies of water also contribute to this cooling effect. Floating solar on the ocean, where temperatures are even lower than on lakes and reservoirs, can produce more electricity still. But it’s also more challenging to build, and only a handful of projects have been deployed.

Key points

• As a potential solution, Chenya Energy built a 181-megawatt offshore floating photovoltaic (OFPV) project – sometimes called a “floatovoltaic” – on 1.8 square kilometres of water in the protected b…
• The year before, the Taiwan Power Company had constructed a 100-megawatt land-based photovoltaic (LPV) project on 1.4 square kilometres near the bay, providing an ideal comparison once researchers…
• Pound-for-pound, the floating solar produces 12 per cent more electricity than the land-based solar, they found.
• Even though it has slightly higher operations and maintenance costs, it generates 11 per cent net profit, as opposed to 8 per cent for the land-based solar.
• “Installing the PV system on the sea, on water, is more difficult than installing the PV system on the ground,” says lead author Ching-Feng Chen at the National Taipei University of Technology.