The rising tide of floating renewables

 —  Article by Jim McClelland
Solar cell panels on water space
Image credit: Shutterstock

From a wind farm off the coast of Scotland to a solar plant on a former coalmine in China, some recent record-breaking renewable energy schemes all share one common trait: they float.

As land becomes increasingly expensive and planning consent for large-scale projects is more difficult to acquire, both the number and size of floating renewables projects are on the rise worldwide – especially solar.

In the UK, the first fully-operational floating solar facility was completed in 2014, on a reservoir at Sheeplands farm in Berkshire. More recently, the largest floating energy farm in Europe powered up in 2016 on the Queen Elizabeth II Reservoir, in Surrey, England. Boasting a 6.3MW capacity, its 23,000 panels of solar PV cover the equivalent of eight football pitches. Coming in at twice that size is the floating solar installation on the Yamakura Dam reservoir, in Japan which will deliver 13.7MW of power.

In 2017, however, the rule book was rewritten when China switched on what is now the world’s largest floating renewable energy plant. With a $45 million price tag, the giant installation of 120,000 solar panels covers an area equivalent to over 160 American football fields and generates enough energy to power 15,000 homes.

Setting new boundaries

In contrast, wind has only taken its first steps with the Scotland installation. This world first, known as Hywind Scotland has a 30MW capacity capable of powering up to 20,000 homes. Its five turbines were towed from Norway to around 15 miles off the coast of Scotland and tethered to the seabed at depths up to 129 meters.

Given that traditional fixed turbines operate typically in waters only up to 60 meters deep, the project illustrates perfectly the potential for floating technology, says Dominic Szanto, Director and Head of Offshore Wind, JLL Energy and Infrastructure.

“There are countries with water too deep for conventional offshore wind where floating technology provides significant advantages – such as off the coast of Japan, west coast of USA and the Mediterranean,” he adds.

Full of promise, the technology is still commercially unproven though says Steven Black, Director – Planning and Development, at JLL.

“The ocean environment brings with it engineering challenges – as has been evidenced by struggles with emerging wave-power technology. The potential, though, is fantastic and allows deeper and more distant coastal waters to be looked at as an option,” he explains.

“Floating technology, will open up new opportunities and could ease some of the challenges associated with existing sea bed-fixed development sites.”

Economics at play

The numbers are stacking up more and more for renewable energy. New technology can be expensive in the short-term, but necessary and cost-effective in the longer-term.

When it comes to wind energy, costs are moving downwards worldwide. “General trends in offshore wind have seen costs coming down quite dramatically, not least with economies of scale coming into play. It was the auctions in the Netherlands and Denmark that proved the real catalyst for falling rates,” says Szanto. “As a result, strike prices that might have been thought revolutionary not so long ago are now operating in the market.”

And these lower costs could act as a big plus point for future floating projects, he believes. “Falling costs for wind and solar already help offset extra charges associated with floating, which combined with the costs involved in acquiring land, makes the business case more feasible and attractive. In addition, there’s no fundamental reason why something that floats should be significantly more expensive, it is just a case of additional pump-priming costs.”

Yet design remains a challenge before floating installations become more widespread. For solar, floating projects may have greater PV efficiency thanks to the cooling effects of the water and marine environment yet they also need to withstand effects of humidity and maybe salt.

At present, there are a number of competing designs for bases or foundations of floating wind technologies and it remains to be seen which ones take off commercially.

A sea of possibility

For real estate, floating energy installations could help to meet the higher energy demands of modern living without taking up scarce land resources. “At very high level, the more you take technologies offshore, the less pressure there is on land use, particularly with demand for housing, urban density and greenbelt concerns,” Black says.

Storing the energy produced is another prime consideration to ensure that countries can meet drops in supply from intermittent sources and smaller grid-feed locations.

While government backing for renewables remains important for consumer and market confidence, the issues of energy use and decarbonisation remain priority topics within the property market. “There is an element of carrot-and-stick, as regulations tighten and occupiers such as RE100 corporates and brands commit to shrinking carbon footprints,” says Black.

“In times to come companies may see higher value in having their own supply via renewable sources. This rising demand will inevitably encourage floating solutions for supply, at least indirectly. Ultimately, in real estate, the full effects of the revolution in floating renewables truly will be felt worldwide when it has an effect on capital values.”

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