Project Overview

Location

Dublin Array is a proposed offshore wind farm on the Kish and Bray Banks, approximately 10km from the coastline of Dublin. These are naturally occurring sandbanks which the busy east coast commercial shipping routes avoid due to the shallowness of the water.

The proximity of the wind farm to the coastline of Dublin, a major electricity demand hub, was a key consideration in the site selection. A reduction in the length of the offshore transmission cables reduces the environmental impact and costs of construction. It also reduces electrical losses. Operational costs are also reduced due to ease of access for maintenance and reduced transmission losses. Cost reductions in the construction and operation of the wind farm ultimately reduce the cost of energy to the consumer.

Key Facts

Based on preliminary results from environmental and technical studies that we have undertaken, the offshore element of the wind farm could include:

Between 39 and 50 turbines
Individual turbine capacities of 15 MW+
Total project capacity up to 824MW
Individual turbine tip heights of between approximately 270 metres and 310 metres

Since Dublin Array was first proposed in 1999, there have been significant technological changes in the offshore wind industry. This means we can deliver more electricity, more efficiently, with fewer turbines. Previously Dublin Array was considering up to 145 turbines, with a tip height of 160 metres, but this number has now reduced significantly. While the turbines will be bigger, there will be fewer of them, therefore reducing the project footprint.

The final decision on the project envelope, i.e. the size and number of turbines, has not yet been made. There are a number of ongoing survey activities which will inform this decision in advance of financial close. The project team are seeking to balance the technical, commercial, and environmental considerations to deliver the best project we possibly can. The feedback we receive from our consultation activities throughout the project planning will help to shape the final design of the project.

How it Works

Wind turbines generate electricity by capturing the natural power of the winds. The force of the wind rotates the turbine blades which spins a generator where kinetic energy (energy due to motion) is converted into electricity.

The electricity produced is then transmitted via cables through the inside of the tower to the seabed where the cables are buried or otherwise protected. Groups of turbines are linked together by submarine cables and each string of turbines is connected into an offshore substation.

A transformer within the offshore substation increases the electricity to a higher voltage to transmit the power produced towards the shore in an efficient manner. The offshore cables are connected to the onshore cables near the coast at what is called a transition joint bay (TJB).

Underground onshore cables will carry the power from the TJB to an onshore substation where it is regulated and harmonised to meet the specifications required for connections into the national electrical transmission system. A short cable then connects the substation to the grid connection point where electricity enters the existing electricity network. Electricity is moved between substations by EirGrid and ESB Networks through overhead lines and underground cables to homes and businesses all over Ireland.