Interview with Edward Walker MIEMA about multi-point electricity interconnector cables

IEMA’s Digital Journalist Tom Pashby spoke with Edward Walker (MIEMA), principal environmental consultant at global energy consultancy Xodus (an IEMA Consultancy Partner) about his work on subsea cables.

What’s new in the world of electricity interconnectors?

There’s a lot coming down the line in terms of new electricity transmission infrastructure upgrades within the UK and related to interconnectors between the UK and our international neighbours.

National Grid Electricity Transmission (NGET) is in the process of consultation for two new subsea power cables from Scotland to England; one from Thorntonloch Beach, which is to the east of Edinburgh, to Seaham, which is south of Sunderland (SEGL1) and another from Peterhead in the north of Scotland, to Bridlington Bay in Yorkshire (SEGL2), each providing 2 GW of transmission capacity. Both of these new cables will help deliver increased capacity from offshore wind and hydroelectric projects in Scotland, down to energy-hungry regions in England. With the likes of ScotWind and its 25GW of additional capacity in the offshore wind, this makes a lot of sense to me.

I have a particular interest in multi-point interconnector cables. These are high voltage cables that run under the sea, connecting power networks between different landmasses, but crucially they also have the capability to link with offshore wind farms to export their power directly. This creates a lot of exciting possibilities including in terms of reducing cost and the ecological impact of export cable infrastructure which individual offshore wind farms currently require on a ‘project-by project’ basis. National Grid Ventures (NGV) are proposing one such cable project called Nautilus which would link England and Belgium, offering potential capacity for integration of clusters of wind farms into a single connection.

What is Xodus’ role in the interconnector sector?

Xodus is a global energy consultancy operating across a range of sectors including offshore wind, carbon capture, utilisation and storage (CCUS), oil and gas, and cables and interconnectors. We are a wholly-owned subsidiary of Subsea 7 group, a global leader in the delivery of offshore projects and services for the evolving energy industry.

Xodus support the development of marine power projects in the UK and internationally, including work on transmission cables, offshore wind, CCUS and various forms of marine energy. We support those projects with our expertise in four key functions: advisory, engineering, environment and supply-chain. In practice for me, this means working with various colleagues across the business to support projects from sustainability, engineering, planning, site identification and feasibility perspectives.

What led to your involvement in subsea cables?

I’ve worked on a range of offshore wind and transmission projects in the past, including whilst I was at the Marine Management Organisation (MMO) (one of the key marine decision-makers in the UK). With the big push for our energy transition, there is currently a very high volume of demand for planning and consenting skills for marine power projects, such as cables and interconnectors.

Who are the key stakeholders in interconnector projects?

The MMO (an executive non-departmental public body which sits under the Department for Environment, Food and Rural Affairs (DEFRA)) and their counterparts in Scotland (Marine Scotland) and Wales (Natural Resources Wales) are some of the key decision-makers for actually consenting these projects. Similarly, the Crown Estate acts as a landlord for the UK seabed and issues leases for deployment. In making decisions, UK regulators are informed by a diverse range of bodies with topic-specific interests ranging from nature conservation to marine navigation, and everything in between! Transmission owners, such as National Grid Electricity Transmission, or organisations such as NGV are typically responsible for actually planning and executing the projects.

These are just a handful of examples, and there are numerous other stakeholders involved in the identification, development, consenting and construction of these complex projects – in my role, I am probably only scratching the surface!

Visions for the future

At Xodus, we’re actively engaging with ScotWind winners on a number of levels. This is the first round of offshore wind leasing from Crown Estate Scotland for around a decade. It may unlock up to 25GW of offshore wind capacity which would be very exciting for the UK energy mix (especially as a large proportion of this, around 60 per cent, is due to come from floating offshore wind). Xodus is involved in providing a range of services to help support ScotWind deployment; this represents an exciting opportunity for us as a company and for the UK’s efforts to achieve net-zero.

Other than this, due to the large number of island populations, Scotland has a lot of marine transmission cables – both inter-island and from the sea to the mainland. A lot of this will need upgrading to account for normal ageing and to help reinforce the network as the energy transition gains momentum. I think this is a really crucial area, given that energy security for so many remote populations in Scotland depends on this network (my time living in Scotland probably makes me especially engaged too).

Aside from our direct involvement in subsea projects, Xodus has recently launched X-Academy. Led by Xodus with support from Energy Transition Zone (ETZ) Limited and ScotWind consortium partners bp and EnBW, this training academy has been built to give people the green skills needed to make the transition to a net-zero future as fast as possible.

Please note: the views expressed in this blog are those of the contributing individual, and are not necessarily representative of the views of IEMA or any professional institutions with which IEMA is associated.