Ørsted: How the First Offshore Wind Farm Changed Energy
In 1991, Denmark commissioned the world's first offshore wind farm near Vindeby, a town named for its windy conditions.
The innovative facility operated for 25 years, producing 243 GWh of renewable electricity before its decommissioning in 2017.
According to the Global Wind Energy Council, offshore wind has now achieved a worldwide capacity of 83 GW.
Constructing the first-of-its-kind facility
Wind speeds offshore tend to register higher readings whilst turbines avoid occupying valuable land space.
Offshore installations can also generate reduced visual impact and produce less noise pollution compared to their onshore counterparts.
Elkraft, a company that preceded Ørsted, first considered the Vindeby concept in 1987 before commencing water surveys in 1989.
"At the time, it was a project many considered simply outrageous and a bit mad," Ørsted's website says.
Elkraft contracted Bonus Energy to provide 11 wind turbines adapted for offshore conditions.
LM Wind Power, now a subsidiary of GE Vernova, produced the 33 blades required for the project.
Engineers sealed the turbines' towers and incorporated air conditioning systems to regulate internal humidity and prolong the machinery's operational lifespan.
Siemens acquired Bonus Energy in 2004, with the entity now forming part of Siemens Gamesa.
Elkraft collaborated with SEAS to construct the wind farm over 11 days, achieving 4.95 MW of nameplate capacity.
Decommissioning and recycling efforts
Between 3 March and 3 September 2017, the Vindeby facility underwent complete dismantling, with all cables, infrastructure and 33 blades returned to land according to decommissioning documentation.
The Technical University of Denmark (DTU) accepted 21 blades as donations, using them to study how wind turbine blades endure decades of operational stress.
Several of these blades were subsequently repurposed as noise barriers alongside Danish roads, as the high-density fibreglass could absorb sound effectively, whilst others returned to their manufacturer LM Wind Power.
Miljøskærm, a fibreglass recycling specialist developing a new methodology, received three blade donations.
HJ Hansen processed the remaining turbines for recycling, whilst Connected Wind, the dismantling contractor, retained certain electrical components as spare parts.
Ørsted and Siemens each received one gearbox for research and exhibition purposes.
The facility's nearly 60 tonnes of cabling underwent recycling, and the reinforced concrete foundations were repurposed as gravel.
The Energy Museum near Bjerringbro, Denmark, received one complete turbine as a donation.
Evolution of offshore technology
Ørsted is currently constructing Baltica 2 in Poland, which could generate the equivalent of Vindeby's entire 25-year output in just one month.
Agata Staniewska-Bolesta, Managing Director of Offshore Poland at Ørsted, says: “The development of offshore wind energy is a key element for Poland’s energy transition, which will strengthen the country’s energy security.
“As Poland’s largest-ever renewable energy project, Baltica 2 will lead the way for Poland’s transition to green energy, producing green electricity to meet the needs of approximately 2.5 million Polish households and deliver first power in 2027.”
Contemporary offshore wind turbines can surpass single-unit capacities of 15 MW, featuring rotor diameters more than double those deployed at Vindeby and hub heights exceeding 100 metres.
Wind farm scale has also expanded considerably, with developments like Hornsea 1, 2 and 3 delivering a combined 5.4 GW upon completion, whilst Baltica 2 is set to achieve 1.5 GW capacity.
According to the International Renewable Energy Agency (IRENA), total global wind capacity expanded from less than 7.5 GW in 1997 to more than 1,131 GW by 2024.
IRENA's research indicates that the levellised cost of offshore wind has declined by 63% since 2010, partly attributable to larger turbines, advanced installation methods and economies of scale.
