Preparatory work for wind farms

In advance of construction of a wind farm on the North Sea there is a careful preparatory process, including statutory procedures. It starts with the designation of a wind farm zone and runs through various steps, up to ultimately organising a tender procedure. Once a suitable party has been selected in the tender procedure, construction on the wind farm can begin.

1. Designation of the wind farm zones

The process starts with the reservation or 'designation' of offshore zones where wind farms can be created. That process of designation is a complex puzzle, as the North Sea is used intensively for many different purposes. New offshore wind farms may be built in such designated areas only. The designation of new wind farm zones is defined in the National Water Programme. The North Sea Programme, which forms part of this, can be viewed as the integrated vision for the Dutch section of the North Sea. This programme provides an initial picture of the locations of the offshore wind farms. A specific challenge related to wind farm zones is to find locations within the framework of the spatial assessment in which, for instance, the wind speeds and seabed situation are favourable and, at the same time, ensure that they do not impinge on other activities in the North Sea. In other words, that shipping, the fisheries, ecology, the designated protected natural areas and interested parties in the immediate environment are taken into account. So, in this phase there is careful consideration of where in the North Sea such developments would be welcome and where that would not be the case.

2. Drafting the Road Map

The Ministry of Economic Affairs and Climate Policy drafts an 'Offshore Wind Energy Roadmap'; a sort of programme booklet that shows when a wind farm (or a specific part of a wind farm) will be under construction. That planning schedule is dependent on market conditions. Spatial developments in terms of other uses of the North Sea are also assessed, such as oil and gas production, for example.

3. Preliminary allocation of sites

It is often the case that the designated wind farm zones are not exclusively used for wind energy. The division of zones into individual sites often leads to the loss of 'off cuts'. It is necessary to take into account the existing use and infrastructure, for instance. This is why the first step is to make preliminary sketches showing one or more sites within each designated wind farm zone. To do this, the Ministry of Economic Affairs and Climate Policy assumes current insights and expectations in the area and factors such as data on wind speed and direction are taken into account. In each case, the aim is to use the space as efficiently as possible. Where more than one site is envisaged within a single wind farm zone, the focus is on equal energy yields. In advance of the site decisions these preliminary sketches may yet change, depending on possible new results from studies and other insights in the area.

4. Research

Extensive research on the particular features and existing use of a wind farm zone is used to map out any preliminary site. The research results are published. This is information that is important to the wind farm developers, such as wind speed, water depth, wave height, condition of the seabed, archaeology and the presence of shipwrecks and unexploded ordnance (UXO). These location studies are carried out by market parties on behalf of the Netherlands Enterprise Agency. For more information, please see the website of the Netherlands Enterprise Agency.

5. Preparatory work for connection to the electricity network (offshore grid)

In order to bring the wind energy produced at sea onto the land, electricity cables have to be laid from an offshore wind farm to a high voltage station on land.

The first step in this process is to draft a so-called Exploration of Cable Landing Points for Offshore Wind Energy (Dutch acronym: VAWOZ). This exploration allows the Ministry of Economic Affairs and Climate Policy to decide which connections from a wind farm zone to the coastline require initiation of a planning procedure. The preparatory work and the subsequent cabling may take between eight and ten years in all, depending on the technology used and the distance from the wind farm to the high-voltage station on land.

The legal framework for the offshore grid is enshrined in the Electricity Act 1998. The government has designated TenneT as network operator for the offshore grid. The permits and the land-use plan, which are necessary for the offshore grid, are generated under the State Coordination Scheme (RCR). This RCR procedure combines and simplifies the consultation and appeals process. An environmental impact assessment, the results of which are taken into consideration in the ultimate choice of route and may also lead to the inclusion of conditions in the permit, is drafted in relation to connection to the electricity grid. An appropriate assessment is also drafted to identify the possible impact on protected ecological features in Natura 2000 areas at sea and on the coastline. The independent Environmental Impact Assessment Committee reviews this in terms of the legal guidelines and subsequently makes a recommendation.

Various permits are granted for the connection to the electricity network. An example of this is formed by the permits under the terms of the Water Act, a review relating to aspects such as social functions.

An Environmental Impact Assessment (EIA) always starts with a Range and Detail Memorandum (NRD). This gives insight into how the environmental impact is studied and assessed. The memorandum, which comes about after a public consultation, offers a solid basis for the substance of the EIA. This not only prevents important matters not being given appropriate consideration, but also limits the range of the assessment. The NRD is based on current relevant developments in both scientific and legal fields. The substance of both the NRD and the EIA is reviewed by the independent Environmental Impact Assessment Committee. The recommendations of the committee are not binding, but are often followed in practice.

6. Site decision

A site decision determines the conditions under which a wind farm may be constructed and operated within a site as designed. A site decision also covers the considerations in the context of the Nature Conservation Act. This relates to the assessment and review of the impact of the envisaged wind farm on protected species and habitats of Natura 2000 areas. An Environmental Impact Assessment (EIA) is drafted to facilitate the decision-making process. The EIA addresses the effects of an envisaged offshore wind farm, focusing on such aspects as marine life, the seabed and existing functions. An appropriate assessment is also drafted to identify the possible impact on protected ecological features in Natura 2000 areas. The EIA is largely a 'desk study'. It continues where previous location studies (see step 4) left off, but also makes use of other knowledge and insights; the results are set out in the ultimate EIA. The Environmental Impact Assessment Committee reviews the substance of this report.

The results of the study may lead to the inclusion of measures to mitigate the effects on the environment in the site decision. The measures to which a site decision must adhere relate to such aspects as the type of turbines that are permitted. This is a wide range of features, such as blade tip height, total rotor surface area and minimum capacity. But the site decision also covers the noise standard for pile driving under water during the construction of a wind turbine and the stipulation that no nitrogen deposition may be caused in Natura 2000 areas (which are sensitive to this) during the maintenance phase of wind farms.

The legal framework for a site decision is the Offshore Wind Energy Act. A site decision is open to appeal (see 'Consultation/participation' below).


During the various phases of the drafting of a site decision and the granting of a permit for the offshore grid there are opportunities for consultation and participation:

  1. Views on the draft NRD (see box) Under the consultation/participation process it is possible to make suggestions as to what could be done additionally or should be explored in a different way in the EIA in order to arrive at a (draft) decision;
  2. Views on the draft site decisions and the underlying documentation;
  3. Once the final site decisions have been made, taking into account all views submitted and responses to the same, they will be open to appeal (by those who are entitled to do so) at the Dutch Council of State, Administrative Jurisdiction Division.

More information can be found at the Netherlands Enterprise Agency's Bureau Energieprojecten Participation and appeal.

7. Tender

Once the site decision is definitive, the Netherlands Enterprise Agency organises a tender procedure for the granting of sites on behalf of the Ministry of Economic Affairs and Climate Policy. Commercial parties with an interest in the site may submit proposals. From all the submissions, the government then selects one party to build and operate the wind farm. This party shall be given a permit for the construction and operation of the wind farm at the site in question.

The Offshore Wind Energy Act has details of the tender instruments.

8. Construction and operation

As soon as the winner of the tender has been announced, the new owner will receive the permit and may start on preparatory work for the construction of the wind farm. At the start of construction, the Ministry of Infrastructure and Water Management will establish a temporary safety zone around the area where actual construction work will be taking place. At that time, access to the zone will be granted to vessels that are involved in construction of the wind farm, that form part of inspections or that have explicit permission only. During operation, too, there will be rules for free passage and for shared use in and around the site. During the preparatory work, construction and operation of the wind farms, Rijkswaterstaat and SodM will carry out monitoring and enforcement. It takes around four years from the point at which a permit is granted until a wind farm is fully operational.