Hexbyte – Tech News – Ars Technica | Floating solar is more than panels on a platform—it’s hydroelectric’s symbiont

Hexbyte – Tech News – Ars Technica |

water and sun —

Floating solar offers a wide range of benefits to hydroelectric dams.

Hexbyte - Tech News - Ars Technica | Two people working on a floating solar installation
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A view of the new floating solar farm being grid connected on Godley Reservoir in Hyde, on February 10, 2016 in Manchester, England.

Ashley Cooper / Barcroft Media / Barcroft Media via Getty Images

A total of 1.1 gigawatts (GW) of solar have been installed around the world as of September, according to a new report by the World Bank (PDF). That’s similar to the amount of traditional solar panel capacity that had been installed around the world in the year 2000, the report says. The World Bank expects that, like traditional solar 18 years ago, we’re likely to see an explosion of floating solar over the next two decades.

That’s because floating solar is not simply “solar panels on water.” Solar panels prevent algae growth in dammed areas, and they inhibit evaporation from occurring in hotter climates. (According to Yale’s School of Forestry and Environmental Studies, major lakes in the southwestern US like Lake Mead and Lake Powell can lose more than 800,000 acre-feet of water to evaporation per year, and the adorably-described “floatovoltaics” could prevent up to 90 percent of that evaporation.”) Additionally, floating solar avoids taking up space on land that is priced at a premium. In Northern California, for example, a floating solar installation was added to a nearby reservoir because the land around it was better used for growing grapes.

Another benefit of floating solar is that ground doesn’t have to be leveled before the plant is installed. Usually, fixed-tilt panels are attached to a floating platform that’s moored to the bottom of the reservoir. Most systems send electricity through floating inverters, although in some smaller installations the inverters are situated on land.

The downside is, of course, cost. Floating platforms and water-resistant wiring are more expensive for water-dwelling panels than for their land-based counterparts. As solar PV panel prices have been falling, however, the extra cost to make a floating system might save it from being considered too expensive.

Hexbyte – Tech News – Ars Technica | Water and sun

The World Bank contends that the real value of floating solar is going to become obvious as more and more panels are paired with hydroelectric systems.

Floating solar and hydroelectric dams actually work in a pretty nice symbiosis. In some areas, hydroelectric dams produce energy in an extremely predictable manner. In these cases, the electricity can be used to augment the more variable solar energy coming from the panels. In other cases, hydroelectric energy wanes in times of drought, and solar energy can be used to augment hydroelectric power when water levels are low. “Floating solar may therefore be of particular interest where grids are weak, such as in Sub-Saharan Africa and parts of developing Asia,” the World Bank writes.

  • First solar panels paired with a hydroelectric damn at the Alto Rabagao Dam in Portugal


  • World Bank example of a floating solar system.

    World Bank

  • Aerial view of the floating solar power station on top of an abandoned coal mine at Nanping Village on April 19, 2018 in Huaibei, Anhui Provinc

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