China builds world’s largest floating solar farm

A massive civil engineering experiment is underway 150 km south of Shanghai and is causing an international wave in more ways than one.

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Floating technology could potentially be capable of providing 50% of the world’s ongoing energy needs** the clean and green technology being tested at China’s Hangzhou Fengling Electricity Science Technology Solar Park will also provide jobs and nutritious food from aquaculture for local people.

So what are the main benefits of floating solar? How likely is it to be implemented around the world as a meaningful solution to the energy crisis? Join us today as we take a trip to the world’s largest floating solar farm.

As our civilization meaningfully grapples with the necessary transition to clean energy sources, many ambitious solutions are proposed. From huge offshore wind farms to huge hydroelectric power plants

A new idea is so obvious it almost seems a little ridiculous. Solar panels are clean, efficient, and improving all the time, but they require a larger footprint, taking up land near population centers that could otherwise be used for housing or agriculture.

But some large projects around the world have realized that an ideal place to hide large solar arrays is on the water, particularly adjacent to existing hydroelectric plants. Experts report that around 10GW of new floating solar farms will be operational by the middle of this decade.

One advantage of putting them on bodies of water already in use over existing hydropower is the lower transmission cost. If the infrastructure for transmitting energy to the grid is already on-site, this is clearly a big plus. But it’s smarter than that.

Hydro and solar power plants are both seasonal – naturally during the dry season, solar is better, but during the wet season hydro is more productive. So together, overall, they can even help each other during their respective lean times.

This is kind of a no-brainer. Not only will the water cool the solar panels, which happens to make them work more efficiently, but the placement of the panels can actually help maintain those all-important water levels in the reservoir.

The coverage by the panels reduces the amount of water that evaporates naturally, which is obviously a huge deal in drought-prone parts of the world. They can also limit the growth of algae, and provide useful shelter for fish and other water life.

So where is the world’s largest floating solar farm? Covering approximately 300 hectares in the Changhe and Zhouxiang reservoirs in Cixi, Zhejiang Province, China, the Hangzhou Fengling Electricity Science Technology Solar Farm currently holds the title.

Built-in two phases – a 300GWH section completed in 2017, powering some 100,000 homes alone, and a later 120MW installment opened a year ago at a cost of around $100m – uses some pretty innovative technology.

Minimal Inverters – Kits designed to convert the variable direct current output of photovoltaic panels into the electrical grid and in turn into useful alternating current to feed into your home. Here inverters need to be designed to deal with wet and sometimes choppy conditions.

In the case of the giant Hangzhou Fengling plant, Chinese inverter manufacturer Shenzhen Keystar Science and Technology provided its catchy names GSL2500C-MV and GSL1250 sealed inverters for the job.

Collectively, the two-phase project now generates approximately 352 million KWH, which should generate approximately $45 million a year in revenue. In addition, the sprawling complex – which required the construction of two new 110-kV booster stations by China’s state-owned Grid Corp, and nearly nine miles of cable – is actually helping the local economy and the marine environment. how?

Solar panels are spaced in the reservoir with sufficient gaps that light can enter and support a healthy sub-aquatic ecosystem. This means that the fish can survive and thrive, with the added bonus that the panels serve as artificial islands that shield the fish from natural predators such as birds.

Locals can also navigate along carefully designed channels and, when the fish reach sufficient size, reel them in for a local and national consumer market. Economic analyzes of the setup have estimated that the value of the local fishing community in terms of income could reach up to $5 million each year.

Overall, with income from electricity brought into the equation, it is believed the plant’s eye-watering $260 million dollar cost will be reduced in seven to eight years.

If the technology can be shown to work reliably – and has so far – it could be a huge game-changer in energy production around the world. For example, a US government study demonstrated that the nation could generate 10% of its national energy needs if similar schemes were launched in US man-made water bodies.

And that is without expanding on natural waterways or oceans. Worldwide, it is believed that 10,6000 TWh can be generated annually by waterborne photovoltaic – meaning solar – panels.

According to 2018 figures from the International Energy Agency, worldwide energy consumption has more than doubled to 22,300 TWh. And many projects around the world are trying to take advantage of the initially encouraging results demonstrated by floating solar technology.

In the Netherlands, a project called Zone-op-zee – which literally means ‘sun in the sea’ – has shown that a promising 17kw array can be scaled up in a modular fashion, and significantly absorb unpleasant buffering by local unpredictable and potentially stormy conditions.

Set to eclipse the Hangzhou Fengling Reservoir project covered earlier in this video, a massive 2.1 GW floating solar plant is currently being assembled by the South Korean government near the Samangeum tidal flats, on the Yellow Sea coast.

Many times larger than its nearest rival, the Korean solar project will cost more than half a billion dollars and will be tied to a new startup cluster that is expected to fuel the next generation of big-thinking green energy initiatives.

It can only be hoped that, like the Chinese project, this and other bold initiatives will balance future energy needs with the economic and agricultural needs of the local people. And if they manage to fix it, it will send a very powerful signal that floating solar is the future.

Source: Complex Ob 7, 15 July 2021.

** Combining floating solar with hydropower could potentially provide 50% of the world’s ongoing energy needs

Wiring in floating solar arrays to existing hydropower reservoirs around the world could change the face of the global energy system by meeting nearly 50% of total electricity demand, according to a potentially market-making study (September 2020) by the US Department of Energy’s National Renewable Energy Laboratory (NREL).

Researchers estimate as much as 7.6TW of power could be produced by the water-top PV. This works out to about 10,600TWh of potential annual generation – even before output from the hydro plants – compared to worldwide electricity consumption which, according to International Energy Agency 2018 figures cited by NREL, was just over 22,300TWh.

The NREL resaerchers counted 379,068 freshwater hydropower reservoirs worldwide that could host floating PV arrays, though noted that “additional siting data [would be] needed prior to any implementation because some may be dry during parts of the year”.

Coupling floating solar and hydropower is seen having a strong rationale for a number of reasons, including that a hybrid system could have lower transmission costs by linking two seasonally-aligned power sources to a common substation and that the two technologies can balance each other with their respective electricity production.

“The greatest potential for solar power is during dry seasons, while for hydropower rainy seasons present the best opportunity. Under one scenario, that means operators of a hybrid system could use pumped storage hydropower to store excess solar generation ,” 

Source: Recharge, 29 September 2020.

See NREL paper:

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