What would a huge offshore wind farm mean for Norfolk?

If you regularly drive through Norfolk, you might be used to getting stuck behind an agricultural or heavy goods vehicle. For motorists travelling from King's Lynn towards Norwich, there is now the added slow-moving traffic of a series of transformers being transported across the county for a substation serving what could become one of the largest offshore wind farms in the world. How will the transformers be used and what part will Norfolk play in it?

With the possibility of producing 2.9 gigawatts of energy - enough to power 3.3 million homes in the UK - the Orsted Hornsea Three offshore wind farm is expected to be the largest in the world.

In December 2021, former Energy Secretary Alok Sharma granted permission for the £8.5bn project.

It is due to be completed in 2027 and will be located 75 miles (120km) off the Norfolk coast, so why has it had such an impact on a rural Norfolk village?

Nestled in the Swardeston countryside four miles (6km) from Norwich, a 49-acre site home to a converter substation is preparing to take offshore wind energy to the National Grid for millions of homes.

Two valve halls on the site - named link 1 and link 2 - convert energy before sending it to the grid.

Paul Ashworth, onshore construction manager for Hornsea Three, has worked for the company for 11 years and lives in Eaton. He said it was a "blessing" to only live 10 minutes from the site.

Work on the site started in 2023 with soil stripping, before concrete foundations were laid, steel frames put in place and equipment landed a year later.

Ashworth said the progress since January 2024 had been "absolutely amazing".

A battery energy storage system on site will also store excess electricity to be used at a later time to help balance the grid.

Transformers are a key part of a converter substation.

They change the voltage produced from the turbines into what can efficiently be used by the National Grid.

Since December, eight transformers for the substation have been transported from the Port of King's Lynn to Swardeston, with a ninth still to come.

Travelling at 12mph (19km/h), it can take up to nine hours to transport the them 46.5 miles (75km) across the county, scheduled on a Sunday to reduce disruption.

While a lot of planning is involved to put police orders in place and give out flyers to residents along the route, Ashworth said it was a "necessary evil".

"To go from King's Lynn Port to here is a huge undertaking, especially with the size of the vehicle they need," he said.

"We have to look at it in a very positive way."

The last transformer will arrive in mid-July, he said.

At the converter substation, link 1 of the project will go live at the end of the year with link 2 going live early next year.

In the North Sea, construction has seen the installation of 197 monopiles which will be the foundations of each wind turbine.

The first monopile was installed in May, and the last one should be in place next year.

Ashworth said the project would be winding down towards the end of 2027.

When proposals were raised for placing industrial batteries at Swardeston to store up energy from the wind turbines, a number of safety worries were raised.

Swardeston Parish Council said it had "grave concerns" about the use of lithium ion batteries and the surrounding technology posing a possible fire risk.

However, Norfolk Fire and Rescue Service had no concerns or objections to the development.

At the time, Orsted said safety was its highest priority.

In 2021, the RSPB criticised the government's decision to permit the offshore wind farm due to the potential harm to wildlife including kittiwake birds.

It said kittiwakes would have to dodge turbines to reach feeding grounds and could potentially lead to the death of 73 kittiwakes each year.

Rosie Pearson is the founder of the Essex, Suffolk, Norfolk Pylons Action Group, which has been campaigning against a 114-mile (185km) network of pylons and cables stretching from Norwich to Tilbury in Essex

She believed there were other ways to carry out energy infrastructure.

"The obvious thing which should have happened years ago is to connect all the power offshore into a connected grid and then bring it onshore near to London where it is needed ideally at a brownfield site, not way inland in the countryside such as near Norwich because that's hugely damaging for communities, nature and it's a more expensive way of doing things."

She said it was better for the environment and cheaper for all the energy, that was generated from these turbines, to be coordinated offshore on "energy islands" - something that has been done elsewhere in the world.

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