Planted 22 kilometers into a Danish sea with 120 blades built to be born twice, the turbine rising at Thor carries a number that rewrites what happens when a wind farm finally runs out of excuses about its own waste
Off the flat western shore of Denmark’s Jutland peninsula, the North Sea runs gray and cold as far as a person can see from the dunes at Thorsminde. Twenty-two kilometers out, a construction vessel the size of a city block is lowering a steel tower into the water. The tower is not ordinary steel, and the blades waiting to be attached are not ordinary blades. Something about this turbine has never been done before, anywhere in the world, and the engineers raising it into the Danish sky know it.
A farm big enough to rewrite Denmark’s grid
The Thor offshore wind farm will be Denmark’s largest when it reaches full power. Seventy-two turbines, each rated at up to 15 megawatts, are being planted across a stretch of seabed 22 kilometers off the Jutland coast. Once commissioned, Thor will supply enough electricity for more than one million Danish households, a striking figure in a country of fewer than six million people.
The offshore substation and all foundations were installed in 2025, and turbine installation is progressing steadily. Thor has already started supplying electricity to Denmark as RWE targets full operations by 2027. The project is co-owned by RWE and Norges Bank Investment Management, and on a gray April morning this year RWE announced the first turbine had gone in, containing a detail that stopped engineers cold.
Thirty-six of Thor’s 72 turbines will carry these towers, cutting the embodied carbon of more than half the farm’s steel backbone by nearly two thirds.
The weight of a steel tower and what it costs the sky
Building an offshore wind farm has always carried a paradox that nobody much likes to discuss at ribbon cuttings. Steel is dirty. Conventional steelmaking is one of the most carbon intensive industrial processes on earth, and a single offshore turbine tower contains hundreds of tons of it. A 1.1-gigawatt farm like Thor requires enough steel to construct a small city’s worth of bridges.
RWE is the first company worldwide to use Siemens Gamesa’s GreenerTower, with plates made from steel that produces at least 63 percent lower COâ‚‚ emissions than conventional steel, using electric furnaces fed by renewable power and scrap metal. Thirty-six of Thor’s 72 turbines will carry these towers, cutting the embodied carbon of more than half the farm’s steel backbone by nearly two thirds. But there is a second problem the industry has spent years struggling to answer, and it involves what happens at the other end of a turbine’s life.
The blade problem that kept coming back
Wind turbine blades are enormous, aerodynamically complex and, for most of the industry’s history, effectively impossible to recycle. Composite fiberglass, layered and bonded under heat and pressure, cannot simply be melted down into a useful second material. When a blade reaches the end of its 20-year working life, the answer has almost always been the same: cut it into sections and bury it.
Hundreds of blades already lie in landfills across the American plains and European countryside. Siemens Gamesa announced a recyclable blade concept in 2021 and has refined it ever since. Thor will be the biggest deployment of this technology yet, and the first time it has been paired on the same site with the greener steel tower.
What the blade becomes next
This is the reveal hiding inside a 1.1-gigawatt construction project. RWE announced in early April that Siemens Gamesa’s recyclable blades use a resin that enables separation of composite materials at end of life, so they can be reused in casting for automotive or consumer goods. A blade that spent two decades catching Atlantic gusts off Jutland could, in its next life, become part of a car door panel or a kitchen appliance housing.
Forty turbines at Thor will feature 120 recyclable rotor blades, each longer than a commercial aircraft’s fuselage, built from the first bolt to eventually return to a material supply chain instead of a landfill. RWE Offshore Wind CEO Sven Utermöhlen framed it plainly: “By using towers produced with greener steel and recyclable rotor blades, we are further reducing the carbon footprint and taking a significant step towards fully circular offshore wind.” Engineers working on blade technology around the world have noted the milestone, and the material science behind the resin is now being watched by every major turbine manufacturer with landfill contracts on its books.
A port town and what comes after the turbines
The human dimension of Thor is less dramatic than the engineering, but it is real. A service building was opened at the Port of Thorsminde to support operations and maintenance, potentially creating 50 to 60 local roles in a small fishing harbor on a narrow strip of land between the North Sea and a freshwater lake.
What makes Thor more than a construction update is the question it poses to every offshore project now in development: if the world’s largest Danish offshore wind farm can source greener steel and recyclable blades at this scale, why would any comparable project settle for less? Norway’s accelerated approvals and similar expansions across Northern Europe will bring hundreds of new turbines to northern waters before 2030, and the blade waste clock ticks with every one of them. Thor proves the technology works at sea, and whether the economics follow at scale is the next question the North Sea will have to answer.
Hugo is an engineer with strong technical expertise. Multilingual from an early age, his writing combines technical clarity with a strong interest in science and energy.
