Powering Châteaudun’s grid connection with Hitachi Energy transformers
Customer Story | 4 min read
As France accelerates the electrification of uses, the development of new renewable production capacities and their connection to the network are becoming essential levers of the energy transition.
In this context, EDF power solutions, a subsidiary of the EDF Group specializing in the development and operation of low-carbon energy projects, particularly in the fields of solar, wind, and storage, is implementing this ambition on the ground.
Among them is Chateaudun solar park, built on a former military airbase in central France, which is expanding renewable generation and bringing new value to the local community. Each year, it will power the consumption of 54,000 inhabitants. To bring this 115 MWc photovoltaic project online with a dependable grid connection, EDF power solutions relied on Hitachi Energy to deliver a turnkey transformer solution from design and manufacturing through installation and commissioning.
The Challenge
Delivering reliability and performance for large-scale solar integration
The Châteaudun project had to respond to both local and European imperatives. It needed to deliver reliable renewable capacity while proving that large solar parks can be integrated efficiently into the French power grid. The project depended on a single critical asset: the main power transformer, responsible for stepping up the generated electricity to the transmission network.
This transformer had to meet stringent quality standards, be engineered and delivered on schedule, and perform reliably for decades. Site access posed additional complexity, requiring precise logistics and close coordination to ensure that installation and commissioning could proceed without delay. Beyond the technical and logistical challenges, the project carried strategic importance: its success would demonstrate EDF power solutions’ ability to contribute meaningfully to France’s renewable energy roadmap and to the EU’s broader energy transition objectives.
The Solution
A turnkey transformer delivery from design to commissioning
The 63/105 MVA, 93/33 kV power transformer was designed and manufactured by Hitachi Energy in Italy. Its job is to step up the electricity generated by the solar panels to the higher voltage required for transmission, the critical link between the panels and the grid, and the one component on which the entire plant's output depends. The transformer is equipped with advanced digital monitoring systems to maximize performance optimization and lifecycle reliability.
Built with the technological edge required for large-scale solar integration, the transformer is engineered to withstand the demanding operating conditions of photovoltaic parks, ensuring not only efficiency and resilience in the present but also durability over decades of service life.
The transformer was equipped with fiber optics and fire-prevention thermal sensors, demonstrating attention not only to technical and operational performance but also to environmental and community aspects.
Hitachi Energy’s local service team in France oversaw the delivery, unloading, installation, and commissioning on-site of the unit, managing all on-site activities with precision and safety, and overcoming difficult access conditions through meticulous planning and coordination.
The Impact
Advancing renewable generation and long-term community value
In October 2026, the Châteaudun solar power plant was successfully inaugurated and connected to the French grid. Today, the plant generates around 130 gigawatt-hours of renewable electricity each year, supplying enough electricity to thousands of households. Beyond this immediate contribution, the project is embedded in a thirty-year agreement with the Grand Châteaudun community, ensuring that the site continues to support local development and contribute to long-term climate objectives.
The Châteaudun solar power plant illustrates how strong partnerships, advanced transformer technology, and precise execution can transform a disused military site into an asset for France’s energy future. With Hitachi Energy’s expertise, EDF power solutions has delivered a flagship project that supports the energy transition targets while creating long-term value for the region and its people.
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