
France in the “Gigawatt Club” with the Largest Photovoltaic Park in Europe
The Horizeo project includes a one gigawatt plant combined with batteries for storage and an electrolyser for green hydrogen
Photovoltaics aims to make a splash also in Europe at the level of individual installations, bringing France into the “Gigawatt club”, which includes countries with enormous solar plants, with at least 1 gigawatt of total power in a single site, such as India, Egypt and Qatar.
The bang will come with the Horizeo project by Engie and Neoen: a mega multi-technological installation to be built in the municipality of Saucats, in the department of Gironde (Nouvelle Aquitaine). There is talk of numbers never seen in the old continent: a 1 gigawatt photovoltaic park combined with batteries for energy storage and an electrolyser to produce green hydrogen, for a total investment of one billion euros.
The green electricity generated by the park will be used for the production of hydrogen and to power the datacenter. What remains will be sold on the market with supply contracts and therefore without resorting to public incentives.
European Projects
At the moment, in Europe, the largest photovoltaic plants are the Spanish ones. Iberdrola completed the 500 megawatt installation Núñez de Balboa a year ago – the largest photovoltaic park in Europe at the moment – and is building the 590 megawatt Francisco Pizarro park.
But as incentives for solar energy decrease, the size of projects also increases elsewhere. Neoen’s 300-megawatt Cestas project, also in France, was completed in 2016, nearly tripling the size of the country’s largest solar plant at the time.
Germany’s largest solar project at the moment is only 190 megawatts. The UK has never exceeded 100 megawatts for an autonomous solar project. Three are awaiting realization, all to be located along with the accumulation of energy. The largest, led by EDF, aims for a maximum capacity of 500 megawatts. The largest Italian photovoltaic park is the Apulian one in Troia, with 103 megawatts installed last year by the Danish company European Energy.
The inclusion of storage alongside photovoltaics exemplifies another growing trend for European projects, even if the French giant Neoen is very active especially in Australia. With Tesla, Neoen developed the world’s largest lithium battery in Australia in 2017, serving the Hornsdale wind farm, upgraded to 150 megawatts of power in 2019. Then last November the same Neoen-Tesla couple presented the Australian project for the Victorian Big Battery, a super-installation of 300 megawatt and 450 megawatt-hour batteries.
Now Neoen aims to build the Great Western Battery, a 500-megawatt, 1,000-megawatt-hour battery complex in New South Wales, which is scheduled to go into operation in 2023 equally important feature of Horizeo.
Focus on Hydrogen

Several European governments are vying for leadership in the emerging hydrogen economy. Germany is already in the lead with aggressive domestic targets and the Rwe utility that is developing dozens of projects. The UK and the Netherlands have large oil infrastructures and the majors BP and Shell to rely on, as well as significant offshore wind resources to be developed.
Belgium’s large chemical industries and refineries have joined the competition, but France is also heavily committed to green hydrogen. The Macron government has recently launched its National Hydrogen Council, in which four ministers collaborate, with responsibility for finance, the environment, industry and innovation. They were joined by the leaders of the French industry, including Edf, Total, Airbus, Air Liquide and Alstom.
France’s national hydrogen strategy plans to invest 2 billion by 2022 and 7 billion by 2030, when it expects to have 6.5 gigawatt electrolyzing capacity. Engie, in particular, has just signed an agreement with Total to develop and operate what will be France’s largest green hydrogen plant, with a 40 megawatt electrolyser that is expected to produce up to 15 tons of green hydrogen per day.
Located in a Total biorefinery in the southern region of Provence-Alpes-Côte d’Azur and powered by over 100 solar megawatts, the project, dubbed Masshylia, has already requested funding from the French and European authorities, with the aim of starting construction in 2022 and to start green hydrogen production in 2024.
Renewable Transition
France, like other European countries, is in the midst of the transition to renewable energy and has just increased its installation target to 44 gigawatts by 2028. Saucats is part of the Nouvelle-Aquitaine region of France, which has a solar capacity target for 2030 of 8.5 gigawatts, but only 2 gigawatts installed. This project, therefore, will significantly help it reach its target for 2030, covering 15% of the planned installations alone.
Interestingly, in seeking to initiate an open and community-centered approach, the key partners – Engie, Neoen, network operator Rte and the Municipality of Saucats – first presented the project to the National Commission for Public Debate (CNDP), which has decided to hold a public debate with members of the community to make them “participate in the development” of the mega-park.
This kind of early-stage involvement is very rare, although it has been shown to increase the consensus of local communities and reduce the likelihood of a major project being hampered by Nimby-type protests. La Nouvelle-Aquitaine has the largest number of jobs in tourism compared to other regions of France, thanks to a large presence of historic locations, from Poitiers to Limoges, passing through Cognac, and there is already talk of letting Horizeo join tours for tourists to the region.