In 2008, winemaker Greg Allen from Napa Valley, California, completed an array of 2,296 solar panels, 994 of which floated on pontoons tethered to the bottom of his winery’s pond. This installation was the world’s first non-experimental floating solar array, and this was over 10 years ago.
Since then, floating PV have increased in popularity in Asia, yet not as much in the USA. Japan has more than 60 installations, the most of any country in the world. Whereas China, a growing giant in the world of renewable energy, is host to the world’s biggest array – the facility went online in 2017 and floats on top of an artificial lake. Its 166,000 panels can produce up to 40mw, which equates to enough energy to power around 15,000 homes.
So, what’s on the horizon?
As the advantages of floating solar continue to become more evident, France has adopted the process and has just unveiled its first floating solar power plant. An artificial lake in a flooded former quarry in Vaucluse, southern France, has now become home to 47,000 photovoltaic solar panels. Now up and running, the panels supply 100% of the energy needs of 4,733 homes – which is close to 10,000 people. Furthermore, it’s the first floating plant in France, and certainly the most powerful in Europe. Although these plants are popular in Asia, and are slowly being adopted across Europe, as we mentioned before, US adoption has been slow.
Is this likely to change?
It’s thought that some recent deals may turn the tide. The US had just 14 installations at the end of 2018, and availability of open land has often been the driver at the small number of US sites.
Good payback is another driving factor – in the case of Kelseyville County Waterworks District in California, the district anticipates that it will recoup installation costs within 8 years of operation. If it becomes clearer that these installations can be economical, more installations could arise. Many of the US installations are recent, so it is too early to know if projected savings are being realised.
Or, the slow growth across the nation could be due to uncertainties about what the technology can really offer – although a study in 2018 considered the technology’s potential on 24,419 artificial bodies of water across the continental US, and it found that utilising just 27% of those bodies of water could produce almost 10% of the nation’s current power generation.
But large-scale successes may be coming in the US – in July 2018, Los Angeles City Council approved a proposal for a 11.6mw floating solar pilot plant at the Van Norman Lakes Reservoir, while the Tampa Bay Water Authority added a reservoir-based solar power feasibility project to its 2019 capital improvement programme.
Finally, the commercial sector is showing its interest as well; solar power development firm Ciel & Terre completely changed its portfolio almost 9 years ago from land and roof-mounted solar, to floating solar. The firm expects floating PV to grow considerably in the US, especially in states such as California where land is expensive, as it considers this to be an ‘untapped niche, and an untapped surface area of the planet’.