The farm consists of 36 wind turbines, of 3 MW each, type V90 manufactured by Vestas Wind Systems A/S. The total surface area of the farm is 30 km2. With a total capacity of 108 MW, Offshore Windpark Egmond aan Zee was the biggest wind farm in the Netherlands in 2006. The construction of new (bigger) wind farms demonstrates that a huge technological evolution is underway.
There are various reasons why some wind turbines are not running. Wind turbines are shut down when maintenance is required, and sometimes they are not running because there is no wind. In the first case they will be set in a save, inactive “maintenance mode”. This was the reason why most wind turbines of NoordzeeWind were not running at the end of 2019. After 13 years of intensive usage grand scale maintenance was necessary, where several mechanical components had to be replaced.
In 2020, the wind turbines were shut down for a longer period of time. The weather was unsuitable for large-scale maintenance at sea in the first months of 2020, so the teams started work in March 2020. On top of that, wind turbine maintenance is taking longer than scheduled due to COVID-19. Since September 2020 approximately half of the wind turbines function properly again. We expect that the remaining wind turbines will be up and running in the course of 2021, which will cause electricity production to reach its initial level.
Bouwcombinatie Egmond developed an innovative method to install the wind turbines. The Svanen, a heavy lift vessel, was used to install the steel foundation piles of the windmills. The windmill towers and wind turbines were then installed with the aid of a crane vessel.
The IJmondhaven in IJmuiden served as the logistical base for all construction work, as it has an open connection to the sea. Here, the components of the offshore wind farm were collected, the parts were put together, and the quality inspections done. The wind turbine parts were moved to the offshore site by ship from here, as well.
In 2002, NoordzeeWind obtained the concession for construction of the wind farm. The site was then studied extensively in relation to currents, wind, environment, and impact on nature. We also talked to many stakeholders, such as local authorities and administrators, NGOs like Greenpeace, partners in the (nature) compensation programme, and scientific and research institutes. The permit process was then initiated. It took longer than expected to obtain all of the required permits, which was due to the pioneering role of Offshore Windpark Egmond aan Zee.
NoordzeeWind agreed to dismantle the wind farm after it stops producing wind energy. With an eye to sustainability, it is important for the wind farm to continue generating power for as long as possible. This depends on the economic lifecycle (positive revenue) and the technical service life of windmill parts.
In 2002, there was a big gap between what was technically possible and commercially feasible. Nearly 20 years later, we are getting near the break-even point at which generating wind energy is possible without a subsidy.
The Offshore Windpark Egmond aan Zee required an investment of more than €200 million. The Dutch government supported the project in three ways:
Via the Milieukwaliteit ElektriciteitsProductie (MEP) scheme
An investment grant under the CO2 reduction plan of the Ministry of Economic Affairs
By applying the fiscal Energie Investerings Aftrek (EIA) scheme
Wind sets the rotor blades in motion. These are connected to the shaft. The rotating motion is accelerated in a gear box and powers the generator, like a dynamo.
The rotating motion is converted to electricity in the dynamo and a transformer steps up the low-output voltage from the generator to a higher distribution voltage level. The electricity is then transported to shore via a cable.
The topmost part of the wind turbine is called the nacelle. The gear box, generator and transformer are in the nacelle, which can turn on top of the tower so the rotor can always be optimally oriented towards the wind. The rotor blades of the wind turbine can be adjusted according to wind conditions, controlling their output. The turbine can also be shut down entirely by turning the blades out of the wind.
At the bottom of the wind turbine tower is a computer that handles all control signals. It decides whether it is safe for the turbine to run. Finally, there is a computer on land to monitor the turbine’s condition (such as output) remotely. The turbine can also be controlled remotely if necessary.
The electricity is brought to land in Wijk aan Zee using an export cable and is incorporated into the national network operated by TenneT. Shell Energy Europe Limited is the buyer and sells the energy to its customers.
The wind farm is split up into 3 sections of 12 turbines each. To transport the electricity generated by the turbines to Dutch households, a separate 33kV cable runs from the three turbines closest to land to the coast. These cables reach the shore at Wijk aan Zee and run through special pipes underneath the beach and dunes. They end at a transformer station that steps up the voltage to high voltage (150kV) and feeds it to TenneT’s national network. The network has been expanded with a 7 kilometre underground high-voltage cable from the transformer station via Wijk aan Zee through Beverwijk to the power station in Velsen-Noord.
Prior to construction of the wind farm, a lot of research was done on the local impact of the wind farm above and below water, such as impact on seafloor life, underwater noise, fish, sea mammals, and birds. The total research programme started during construction in 2006 and ran until 2012, yielding lots of data on the impact of the wind farm on the local environment. These studies were conducted by independent research institutions.
Go to the Reports page for the reports relating to the possible impact of the offshore wind farm on nature and its environment.
When the site at sea was selected, the interests of all other users of the North Sea, such as fishery, recreational sailing, shipping, sand extraction, military areas, and oil and gas extraction, were taken into account. Requirements were specified particularly in relation to safety to ensure that no hazardous situations would occur for fishermen and shipping lanes. These requirements relate to lighting, colour use, marking, and use of acoustic signals, such as fog horns.