How we work onshore

Here’s how we bring green electricity produced by our offshore wind farms to millions of UK homes.

Our vision is a world that runs entirely on green energy. We believe offshore wind will play a vital role in this future and will be the backbone of a clean, reliable, affordable energy system.

The UK is the world leader in offshore wind and is home to the world’s largest offshore wind farms. It has become one of the country’s largest growth industries and has already generated thousands of highly-skilled jobs, attracting billions of pounds in investment. By 2030, the UK will get about a third of its electricity from offshore wind.

Why is onshore infrastructure needed?

Generating wind power offshore is only half the story―clean electricity needs to be carried onshore and connected to the National Grid, before it reaches millions of homes across the UK. When offshore turbines generate power, electricity is carried through underwater cables via an offshore substation towards the shore. The offshore substation steps up the voltage, so it can be transmitted with fewer losses. Export cables, buried underground, then transfer the electricity to an onshore substation where it is converted to the correct voltage and fed into the Grid.
How to build an offshore wind farm

Why do we need to bury onshore cables?

 

We recognise the sensitivity of landscapes and understand what this means to local stakeholders and residents. By burying our cables, we reduce the visual impact that can arise from the installation of overhead cables and pylons. It also provides better protection for the cable and minimises disturbance to local communities, traffic and major infrastructure.

We carry out a lot of work before deciding where the cables will be buried, including environmental and technical assessments and considerations from local stakeholders.

What is Horizontal Directional Drilling?

When laying cables, we often need to cross existing infrastructure such as roads and railway lines. To avoid possible disruption caused by traditional open trenching methods, we implement a technique known as Horizontal Directional Drilling (HDD). This method allows us to install cables underground quickly without disturbing surface structures, therefore minimising disruption.

Hornsea Two Horizontal Directional Drilling

Caring for the environment

Taking good care of the natural environment is one of our core values. Each of our project teams has at least one dedicated environment officer who is responsible for undertaking an environmental impact survey before any construction begins, and ensuring all wildlife is cared for during construction. This protects animals like seals and migratory birds.

Our pledge is to return everything as we found it. For example, when we excavate trenches to bury cables, we recover them neatly with the original soil. We replant vegetation, and restore everything to the way it was, removing any trace that we were ever there.

What onshore work have we completed so far?

We have 11 operational offshore wind farms in the UK, Hornsea One and Hornsea Two under construction and a further three in our development pipeline.

Fact:  The offshore export cable for Hornsea One totals 467km (290 miles), around the same distance as London to Newcastle, plus it has an onshore cable route of 38km (24 miles) connecting each of the three subsea export cables to the national grid. It is the longest AC offshore wind export cable system ever to have been installed!

Unearthing archaeological discoveries

Key archaeological finds

  • Two human burials (one medieval and one Roman) near Killingholme
  • Metalwork, animal bones and Brone Age pottery in Holton-le-Clay
  • Marine and fresh water shells, including oyster shells which appear to have been a favourite in Tetney during the Roman period
  • A previously unknown Anglo-Saxon settlement in Laceby
  • Two medieval salt production sites in North Coates

As well as connecting 11 wind farms to the grid, our onshore work has unearthed some exciting discoveries. More than 30,000 archaeological sites and objects have been located along the cable route for our Hornsea One Wind Farm. Archaeological excavations took place in advance of cable installation and ongoing monitoring continued throughout cable trench work and land reinstatement.

The archaeological finds discovered along the Hornsea One cable route will be stored and available for public viewing at the North Lincolnshire Museum.

Offshore wind transforming communities

The people of Grimsby explain how offshore wind is transforming their town