The Gemini Offshore Wind Park in the Netherlands' North Sea has been officially opened.
With a 600 MW generating capacity, Gemini is one of the largest offshore wind parks in the world. It will produce 2.6 TWh of sustainable energy every year, reducing the Netherlands’ CO₂ emissions by 1.25 million tons.
To celebrate the opening, a special dome tent was erected in which a 360-degree video allowed visitors to imagine themselves taking a tour of Gemini’s wind turbines as they rotate out in the North Sea (above).
Over the next fifteen years Gemini will meet the energy needs of 1.5 million consumers. This is equivalent to the combined energy needs of all the citizens of the Netherlands’ three Northern provinces. The reduction in CO₂ emissions is comparable to the emissions of 50,000 cars that each drive 25,000 kilometers (15,000 miles) a year.
Gemini is invisible from land, located 85 kilometers (53 miles) off the coast of Groningen in the North Sea. This location has some of the highest and most constant wind speeds in the North Sea, with an average wind speed of 36 kilometers (22 miles) per hour. The turbines turn at five to 13 revolutions per minute, and the turbine hubs are 88.5 meters (290 feet) above sea level. Water depths at the site are between 28 and 36 meters (90 and 120 feet).
Gemini covers an area of 68 square kilometers and is comprised of 150 Siemens wind turbines with a capacity of 4.0MW each. This included 450 turbine blades, each weighing 18 tons. The farm has two offshore high-voltage substations, each connected to a land station in Eemshaven by a 110-kilometer export cable. There, the electricity is converted to 380Kv and conveyed to the TenneT power station.
Gemini has licenses to operate the wind farm for 20 years. After this period, the wind farm and everything that has been introduced onto the seabed must be removed. A bank security of €40 million ($44 million) has been made available for this. Economically, and if well-maintained, the wind farm can last much longer, especially if turbines are replaced with new turbines that may be even more efficient. To maintain the wind farm, an average 20 maintenance technicians will be based permanently at sea.
An app to continuously track Gemini’s offshore wind speed, the amount of energy produced, and the total CO₂ reduction was introduced at the grand opening event and is available for free download.
Four companies have an interest in the project: Northland Power (60 percent), Siemens (20 percent), Van Oord (10 percent) and HVC (10 percent). The construction of the wind park required an investment of 2.8 billion euros ($3 billion). The project was financed by 25 banks from Asia, Australia, Europe and North America. To date, Gemini is the largest project financing for an offshore wind park.