Power transformers: why lead times are exploding

The equipment everything flows through

Between a 400,000-volt line and a workshop socket, electricity changes voltage several times. At each step, a transformer. A written question published in the French Official Journal in September 2026 points out that 90% of the electricity consumed in France passes through this equipment.

Grid operators therefore buy it in large numbers: about 30 power transformers a year for RTE, and about 21,000 distribution transformers a year for Enedis, compared with 14,000 in 2022.

From two years to five

Before demand surged, a large power transformer was delivered in two to two and a half years. Lead times now reach up to five years in France. In the United States, analysts cite up to four years for high-capacity units, and demand for generator step-up transformers there nearly quadrupled between 2019 and 2025.

As a result, French grid operators are booking production slots abroad until 2031.

Three causes that add up

Simultaneous demand. Renewal of ageing grids, offshore wind and solar connections, industrial electrification, data centers: every market is accelerating at once, in Europe and North America alike.

A concentrated raw material. A transformer's magnetic core is made of grain-oriented electrical steel. Global output relies almost entirely on two plants, in Japan and South Korea. Any strain on this steel hits transformer factories directly.

Manufacturing that is slow to scale. A large transformer is custom-built, wound and assembled largely by hand, then tested on a test bay. Opening a new plant or line takes several years, and skilled labour is scarce.

What the shortage means for a project

The transformer has gone from standard equipment to a critical schedule item. For a substation, an industrial connection or a data center, this has very practical consequences:

• order early, sometimes before all permits are granted, with clauses that protect the project owner if the project changes;
• freeze the specification as soon as possible: any late change (voltage, rating, cooling, noise level) can send the order to the back of the queue;
• standardise where possible, to reuse a design that is already qualified;
• follow manufacturing closely: design reviews, factory inspections and acceptance tests, so that a defect found on site does not add months of delay;
• prepare for arrival: heavy haulage, civil works, oil containment pit and installation must be ready on the day the equipment is delivered.

A skill that is becoming strategic

This situation puts a premium on precise know-how: writing the right technical specification, following a supplier in the factory, witnessing tests and fitting the equipment into a tight project schedule. These are systems engineering and project management roles, at the junction between the manufacturer, the grid operator and the project owner.