Hornsea 3 wind farm set to deliver a brighter future

All that clean renewable electricity needs to be brought onshore and connected to the National Grid’s main substation in Norwich before it can reach millions of homes across the region and the UK.

That requires the construction of onshore infrastructure and 51km of cables to be buried underground onshore.

Ørsted’s aim is to be a good neighbour. As the company builds the infrastructure necessary to deliver all the green energy generated offshore to millions of homes onshore, it strives to do it in a low-impact way that respects local residents, Norfolk’s beautiful natural landscape and local wildlife.

How does offshore wind energy connect to the grid?

Hornsea 3 will be the world’s single largest offshore wind farm when it becomes operational. Its offshore wind turbines will be connected together by nearly 600km of array cables.

Those cables will link into two offshore converter stations that will act as transformers and convert the electricity to the correct voltage to transmit it onward to shore via export cables.

From Weybourne on the Norfolk coast, underground export cables will transfer the electricity to an onshore converter station at Swardeston, just south of Norwich. Then the power will again be converted to the correct voltage and fed into the National Grid.

Mel Vila Flores is responsible for all of the onshore cables for Hornsea 3 and explained how they work.

“Think of electricity as a fleet of delivery trucks. Just like trucks need roads to transport goods, electricity needs its own pathways,” said Mel. “Export cables serve as the highways for electricity. They carry electrical energy from its source to where it’s needed – our homes, businesses and communities.”

Mel Vila Flores, Hornsea 3’s cable package manager (Image: Ørsted)
The export cables connect the wind turbines to the grid. Without that connection, the renewable energy generated offshore could never reach our homes or businesses, Mel explained.

With Hornsea 3, the export cables will cover a total distance of approximately 221km – 170km submerged underwater, and 51km buried underground onshore. Once onshore, the cables are buried underground to reduce visual impacts and minimise disturbances.

“Next time you turn on a light or charge your phone, remember that power cables are the unsung heroes ensuring that electricity travels smoothly from its origin to your doorstep,” said Mel.

Caring for the environment

Ørsted spent years conducting environmental impact surveys before construction began on Hornsea 3.

All of the construction work is carefully planned and coordinated in advance to mitigate any potential disturbance to marine life, birds, animals and the local community.

For instance, in order to avoid any possible disruptions caused by traditional open trenching, the company uses a technique known as horizontal directional drilling. With this method, it is able to install cables underground quickly without disturbing surface structures or ecology. It enables the project to reduce the disruptions that can come from large-scale infrastructure works as much as possible.

“Our pledge is to return everything as we found it,” said Jason Ledden, senior director for Hornsea 3, who is responsible for the team delivering the onshore and offshore cable installation.  

Senior project director Jason Ledden (Image: Ørsted)
“For example, when we excavate trenches to bury cables, we reinstate them neatly with the original material and topsoil. We replant vegetation and restore everything to the way we found it whilst working in cooperation with the landowner.

“At the end of the day, our aim is to deliver more than green energy – we want to leave a lasting positive legacy for Norfolk and the UK,” he added.

The project is well on its way, making vital connections every day to deliver the green energy produced offshore to millions of UK homes and businesses onshore.

For more information, visit hornseaproject3.co.uk