French floating solar spreads to hydro sites but competition lags

EDF project on a dam in the Southern Alps highlights the huge potential for floating solar in France but more developers are needed to drive down costs.

EDF is set to commission its first floating solar array in France early next year, marking an expansion in market activity from disused quarries to the country's vast array of hydroelectric sites.

EDF, France’s state-controlled power utility, will commission 20 MW of floating solar capacity at its Lazer hydroelectric facility in the Southern Alps and is developing other projects in France and abroad, it said. The Lazer solar array will span 24.5 hectares, about two-thirds of the reservoir’s surface, and generate a similar output to the hydro plant. France has around 25 GW of hydroelectric capacity and over three quarters is operated by EDF.

   France's hydroelectric capacity by region

                              (Click image to enlarge)

Source: Grid operator RTE

Floating solar activity is growing as land becomes more scarce and governments chase higher renewable energy targets. European governments are opening up hydroelectric sites to accelerate growth.

Hydroelectric facilities offer readily available grid connections and reduce permitting risks that continue to hamper land-based solar and wind projects. Solar complements hydro as solar resources are often highest during times of low water supply and developers in Portugal have combined different solar and wind technologies to produce highly competitive prices.

EDF was awarded the Lazer project in a national tender for ground-based solar projects in 2018. To maximise competition, France would need to follow Portugal's lead and encourage new entrants to develop on EDF's hydroelectric facilities. In Europe's largest floating solar auction, Portugal awarded projects to a number of developers that will be built on hydroelectric sites owned by state utility EDP.

France has fallen behind on its renewable energy targets and floating solar could help it catch up, Camelia Farchado, a Paris-based solar engineer at advisory group DNV, told Reuters Events.

France currently operates 13 GW of solar capacity and the government’s long-term energy plan (PPE) sets a target of 21 GW by 2023 and 35.6 GW-44.5 GW by 2028.

Emerging market

Asia is currently the largest floating solar market but activity is growing in Europe and the U.S. holds huge potential.

                     U.S. potential floating solar capacity, utility rates

                                                               (Click image to enlarge)

Source: NREL report 'Floating Photovoltaic Systems: Assessing the Technical Potential' (2019)

Developer Akuo installed Europe's largest floating solar array in a disused quarry in Piolenc in southeast France in 2019. The 22 MW O’MEGA1 scheme comprises 47,000 panels and floating systems developed by Ciel & Terre and larger projects are now being developed.

Last year, Developer RES secured planning permission to build a 66 MW floating solar project in the former Blandin quarry in north-east France and is developing 200 MW of projects across the country. France could host 20 GW of floating solar nationwide, Courcambeck said.

Disused quarries and sandpits are often “low hanging fruits” as they present less technical, regulatory and permitting risks than hydroelectric sites, Michele Tagliapietra, Global Practice Lead Floating Solar, Energy Systems at DNV told Reuters Events. Sites with lower land values are often favoured in bidding mechanisms. Developers in the Netherlands targeted similar sites early on, allowing them to gain deployment learnings and improve technology.

France's large hydroelectric fleet offers huge floating solar potential but shifting water levels at hydroelectric facilities create additional risks and require special anchoring and mooring systems.

Construction of the Lazer project began in March 2021 and commissioning has been delayed until early 2023, mainly due to low water levels preventing barge manoeuvres required for installation, EDF said. The company will be able to apply learnings on weather conditions and coordination between solar and hydroelectric teams to future projects, it said.

Global learnings

Floating solar activity is picking up in Europe as technology gains have made it "bankable," Vincent Grumetz, Managing Director, EMEA at Ciel & Terre, said.

In France, the development process remains "quite long," he noted.

EDF has already developed floating solar projects in Israel and U.S. and is gaining scaling expertise in Asia where it is building a 240 MW array on the 1.1 GW Nam Theun 2 hydropower dam.

Developers are using economies of scale to drive down costs. Technology optimisation and standardisation is particularly beneficial at hydroelectric sites, where anchoring and mooring systems increase costs.

Floating solar technology is still relatively new and further savings are expected in design, manufacturing and installation, Tagliapietra said.

As activity grows, the entrance of new manufacturers and developers should further reduce costs, potentially bringing "new concepts and when the pipeline justifies, mass production,” he said.

Reporting by Neil Ford

Editing by Robin Sayles