Electricity interconnectors

Sub-sea interconnector arrangements, where electricity systems of different countries are connected by sub-sea cabling, are becoming an increasingly attractive option for countries to share and trade energy, and thus supplement their own inconsistent renewable energy supply.

Currently, the UK has 9.8GW of interconnect capacity provided by nine interconnect systems. Of these, the longest interconnects are the 720km North Sea Link, connecting the UK and Norway, and the 765km Viking Link, connecting the UK and Denmark. These interconnects enable the export of surplus wind power from the UK, and the import of power from Norway and Denmark, during periods of low energy generation in the UK.

Interconnector systems can provide resilience to a country’s inconsistent renewable energy generation capability, and offer an attractive option to offload excess renewable energy to supplement another country’s demand. Indeed, interconnectors are seen as an important component to the UK Government’s net-zero target, with a planned tripling of interconnector capacity by 2030.

While new interconnector systems have been proposed that will connect the UK with each of France, the Netherlands and Germany in the coming decade, one ambitious proposal, the Xlinks Morocco-UK Power Project, aims to provide the UK with 3.6GW of interconnector capacity by harnessing the more consistent renewable energy generating capability of Morocco.

The Xlinks project has the highest capacity of interconnect projects currently being proposed, and while the project is currently only in preliminary stages, in August 2023 the project was declared by Claire Coutinho, the UK Government’s Secretary of State for Energy Security and Net Zero, to be a project of “national significance”. The project hopes to be operational within a decade, and promises to supply the UK with up to 8% of the UK’s electricity consumption.

Energy generation

The energy will be generated from solar and wind farms located in the Guelmim-Oued Noun region of Morocco, where Xlinks has secured a 50-year lease from the Moroccan Government to build a 10.5GW solar and wind farm.

The project intends to harness the high solar intensity of the desert in the region, along with the naturally-occurring trade winds caused by the temperature differential between the Atlantic ocean and African continent, to provide a consistent supply of solar and wind-generated energy.

Crucially, accessing energy generation further afield decreases the seasonal variation experienced by the UK and much of Europe, and also provides access to a region with different weather patterns and daylight hours. For example, Morocco has the third highest global horizontal irradiance (GHI) in North Africa, 20% greater than Spain (the highest GHI in Europe) and more than twice that of the UK. Morocco also provides triple the solar intensity of the UK (34% vs 11%).

Energy storage and transmission

Energy generated from the solar and wind farms will be stored in a 22.5 GWh battery system, which will assist with supporting variations in supply. This battery system, combined with the energy generation capabilities, should allow the project to supply consistent peak energy for 19 hours a day on average .

Once generated in Morocco, the energy will be transmitted through 3,800km of high voltage direct current (HVDC) sub-sea cabling to connection points in England, with the cable passing by Spain, Portugal and France, and following the continental shelf on the sea floor.

HVDC systems are more cost effective and result in lower power loss for inter-country power transmission over longer distances compared to alternating current systems, and as such are used for all current interconnector projects.

Summary

The UK Government is considering various technologies to support the move towards net zero, and ambitious interconnector projects such as Xlinks will play an important role in complementing and supplementing the UK’s renewable energy generation capabilities going forward.

Useful links

• Ofgem, energy policy and regulation programmes, gas interconnectors: dycip.com/interconnectors-ofgem
• UK Government Department for Energy Security and Net Zero, energy white paper, “Powering our net zero future”, 18 December 2020: dycip.com/energy-white-paper-ukgov
• Xlinks, Morocco-UK Power Project: dycip.com/morocco-uk-power-project-xlinks
• Xlinks, response to the UK Government Environmental Audit Committee’s “technical innovations and climate change: onshore solar energy” call for evidence(PDF): dycip.com/xlinks-evidence-ukgov