In 2021, a project attracted international media attention: a submarine electricity cable spanning more than 3,800 kilometers, connecting solar and wind farms in southern Morocco to British consumption. Called Xlinks, this ambitious project promised to transport up to 10.5 GW of low-carbon electricity—about 8% of the United Kingdom’s needs—via a high-voltage cable crossing the waters of Portugal, Spain, and France.
But after several years of lobbying, studies, and promises, the project was frozen. The reasons are numerous: astronomical cost (over €29 billion), difficulties with diplomatic coordination, passage through complex sovereign waters, and growing skepticism about the long-term viability of such a remote connection. The Xlinks case is emblematic of the contemporary challenges of large-scale energy networking. It poses a simple but crucial question: how far can Europe (and its neighbors) connect their energies to gain resilience?
An Already Well-Networked European Electricity Grid
The European Union has one of the densest interconnected electricity grids in the world. Through the ENTSO-E (European Network of Transmission System Operators for Electricity) organization, 35 countries—including non-members such as Switzerland and Norway—share and balance their electricity through more than 400 cross-border interconnections.
The idea behind this energy integration is based on a simple principle: diversify sources, pool risks, and balance variable generation (solar, wind) with controllable sources (nuclear, hydro). When France overproduces thanks to its nuclear fleet, it exports to Germany or Spain. When Germany has a surplus of solar power, it sends electricity to Poland or the Netherlands.
Thus, surplus electricity is not wasted but can be used in other countries without the need for storage investment, the cost of which remains one of the major challenges today.
Interconnecting, yes… but to what extent?
While the European interconnection is technically robust, it is not unlimited. Several factors hinder its expansion or reliability:
- Physical and environmental limitations
High-voltage lines, especially underground or submarine interconnections, require heavy, expensive, and time-consuming infrastructure. The InELFE project (France–Spain), for example, took more than 15 years to complete, with costs approaching €700 million for only 2 GW of capacity.
- Diverging national interests
Each country retains control over its energy security. In times of crisis (e.g., war in Ukraine, drought), some states limit their exports, which unbalances the market. Thus, in August 2022, France found itself a net importer of electricity, partly due to the unavailability of its nuclear power plants… but also due to a lack of operational interconnections, which were sorely lacking among other European energy partners.
- The Challenge of Intermittent Renewable Energy
The more Europe shifts toward solar and wind power, the more the variability of flows makes their stabilization complex. Interconnection is no longer enough: storage, distribution, and planning are also required.
This requires huge investments in batteries, pumped-storage stations (PSS), and potentially, green hydrogen.
These political and financial issues have made energy sources an ongoing debate within the European Commission, as to whether or not to continue massive investments in intermittent or controllable energy sources. However, we see that these two types of energy sources are less and less opposed but complementary, which would contribute to better stability of the network while respecting ecological commitments while needing to renew or create these European interconnections which are still in the planning stages.
The Dream of a Total European Interconnection
The European Commission has nevertheless made progress on certain projects and announced that 13 projects are on the list of projects eligible for subsidies for interconnections within Europe and with third countries.
To be included in this list of interconnections eligible for these subsidies, the electricity must pass through at least two Member States, or at least one Member State and at least one third country. In this way, we can find in the projects announced by the European Commission projects such as Med Link, a partnership between Italy, Algeria and Tunisia aimed at deploying around 10 GW of solar energy, onshore wind and battery storage in the two North African countries, for local use and export
Other projects between Member States have also been announced, such as the Pontis project for the transfer of renewable energy for international supply, led by Spain and the Netherlands.
Finally, it should be remembered that these interconnections do not only concern electricity exchange projects but also energy in general.
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