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Connecting offshore wind power to the UK electricity grid

SSEN Transmission is supporting the UK’s energy transition.


Electrifying our energy supply brings huge opportunities for growth – but making the most of it means grasping the specific challenges ahead of us and acting on them quickly.

Collaborating with SSEN Transmission, we mapped and shaped a supply-chain strategy for six crucial transmission network developments, securing skills and supplies in time to contribute to the UK’s climate targets.

When was the last time you stopped to appreciate access to power, at the simple flick of a switch?

In reality, moving power from its source to our homes is anything but simple. And as we scale up our renewable energy capacity, harnessing power from the wind and sun is a big challenge. It requires new green infrastructure – wind turbines, solar panels and thousands of miles of transmission cables, along with the substations that make up the national grid.

Without it, we can’t meet the UK targets to slash our shared carbon footprint. But with the right planning, it’s hoped that the energy transition will bring benefits even broader than a cooler planet, cleaner air and sustainable ways to power our kettles and smartphones.

For example, there’s the security that comes from home-grown power and greater insulation against global energy price shocks. And it’s hoped that there’ll be economic benefits in the form of new opportunities.

“One of the UK’s clean-energy goals is to create enough offshore wind-power capacity to power every home in the UK,” says Deloitte’s Susan McDonald. “It’s exciting to see change happening - and to think of the opportunities it can bring for sustainable growth in the UK.”

“Businesses and public-sector bodies can work together to understand the specific needs of the new green infrastructure being planned and created in the UK, along with the gaps in skills and supplies, and how to fill them.

“But in a competitive global environment, to make the most of the opportunity, it has to happen quickly.”

One of the companies at the forefront of the UK’s energy transition is SSEN Transmission.

Its ambitious commitments and investments in renewable energy infrastructure include huge wind farms taking shape offshore in the North Sea and six major new energy transmission network developments that will take renewable power from where it is generated, to where it will be used.

This new infrastructure is critical to the UK’s planned expansion of wind power, so it’s a vital step on the way towards meeting climate targets. But there are big challenges involved.

“Scaling up the transmission network in the north of Scotland is one of the most challenging elements of SSEN Transmission’s overall task of contributing towards delivering on the Scottish and UK Governments’ net zero targets,” says John Scott, Programme Director, SSEN Transmission.

“And the growing demand for the components and expertise we’ll need has been forecasted to outstrip supply every year to 2030.”

Specifically, supply chains for the HVDC cables, needed to transfer power over long distances from offshore, have been concentrated in Europe with a small number of suppliers.

Securing them in time was by no means a certainty. To reduce the risk, SSEN Transmission asked our Sustainability and Climate Strategy Team to collaborate on a short project, to explore a robust HVDC supply chain.

“At the start, no supply chains were in place for the networks,” Susan continues, “but in less than three months, we were able to map and secure global, competitive HVDC supply chains for all six of the projects to be delivered within their delivery timelines.

“And four of those projects will be built before 2030.”

“SSEN Transmission is on track to deliver six major transmission network developments within the set timeframes. Without this work we wouldn’t be able to say that today.”
John Scott
Programme Director, SSEN Transmission

Creating a robust HVDC supply chain

Together, the combined SSEN Transmission and Deloitte project team threw out old assumptions, prioritising collaboration and progress above all else. The approach is an example of how supply-chain planning can work to the UK’s benefit.

“We want it to be a catalyst for other infrastructure builders to look at their five and ten-year plans, explore how to stimulate supply chains in the UK and be ready to take advantage of what’s forecast to be a tsunami of demand,” says Susan.

A clear view of the challenge

When we began the project, UK regulations weren’t geared towards the specific challenges of securing supplies and skills quickly in a highly-competitive market. Together, we engaged stakeholders in a dialogue about the realities of the supply market today, based on rigorous, independent research. It was an important step towards demonstrating to Ofgem and the UK Government that regulation-change was needed to help the UK compete.

A new model to protect investment

Changes to regulations, made by Ofgem and the UK Government, allowed SSEN Transmission to speed up the procurement process, lowering the definition of the of detail needed up front at such an early stage.

Certainty to get ahead of the game

“As soon as we had certainty about the regulatory change, we were out there in the market, procuring the suppliers we needed,” says John. “Being able to move quickly has helped to re-shape our view of what’s possible. Because the HVDC supply pool is small, others looking to build the same infrastructure now won’t be able to complete work until the mid-2030’s.”

Creating opportunities in Scotland

Sharing details earlier gave visibility and insight to potential suppliers about to skill up and prepare in the right way to establish new capabilities in the UK. Now, recognising it as a place with manufacturing capability, suppliers are making plans to establish plants in Scotland, creating jobs and investment opportunities.

How does power generated offshore get to our homes?

Just one sweep of the blades of an offshore wind turbine can power a home for a day. But how does the energy get from the turbines to our homes?

When the wind turns the blades, they spin a generator that creates an electric current, which is transmitted through cables to their first destination - large sub-stations, important entry points to the UK National Grid.

High Voltage Direct Current Cables (HVDC) are the most effective way of transmitting energy across long distances, like from miles offshore to the nearest sub-station.

So, for offshore wind in particular, these cables are essential for the first part of the power's journey.

Once it's entered the grid, the power travels through a network of smaller sub-stations, until it's eventually supplied to our homes via an underground cable or overhead power line.

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