Imagine a world where energy is secure, stable, and affordable. No matter what country you live in. In this world, energy flows freely from continent to continent thanks to high-voltage direct current (HVDC) cables that connect them underwater. And that’s how solar power generated in sunny Morocco is used to light homes in the UK or wind energy from the North Sea helps power factories in India.
That's the simplified idea behind creating a global supergrid that could ensure power is where it's needed most. And today, such a supergrid is no longer just the bold dream of idealists but is gaining momentum. So what are the promises and pitfalls of connecting continents' grids across vast oceans? Let’s take a look while also exploring the progress that has been made so far.
From Interconnectors to a Global Dream
As the world is working to decarbonize, a three-way balancing act known as the energy trilemma is taking place: electricity must be delivered that is secure, sustainable, and affordable.
For nations to achieve this, the importance of the electricity interconnector comes into play. It’s a transmission line, typically high-voltage direct current (HVDC), that connects the power grids of different countries and/or regions. In this way, they can share electricity across borders, making it easier to integrate variable renewable energy sources, such as wind and solar.
Today’s interconnectors are mostly regional, but the idea of a global electricity supergrid has existed for decades. In Europe, the concept of a region-spanning energy transmission system was first explored in the 1960s. Different nations envisioned linking their grids for mutual energy security, and this was largely achieved. Today, it boasts over 400 interconnectors serving nearly 600 million people with a combined capacity of 93 GW. This is, in fact, the largest interconnected electricity grid in the world. However, today, the idea of the global supergrid has evolved from its early beginnings, thanks to dramatic improvements in HVDC technology and falling transmission costs.
Image: Chalmers University of Technology, Renewable and Sustainable Energy Reviews, CC BY 4.0 Source: PV Magazine
China has become one of the loudest proponents of the global supergrid through GEIDCO (Global Energy Interconnection Development and Cooperation Organization). Meanwhile, India is advancing a similar idea through the One Sun One World One Grid project, which aims to connect countries across Asia, the Middle East, and Europe with a unified renewable energy network. In Europe and North America, a coalition of policy experts is advocating for an electricity bridge between the two continents, known as the North Atlantic Transmission One - Link (NATO-Link) initiative. According to the think tank Ember, this would not only be a “technical upgrade, but a strategic one” as energy security would be strengthened on both sides of the ocean while balancing renewable energy across time zones.
What We’ve Built So Far
Across Europe, Asia and beyond, multiple projects are already making long-distance electricity transmission a reality.
@Recharge News has outlined some major initiatives at various levels of development:
- North Sea Link: A 720 km subsea cable connecting the UK and Norway for a bidirectional exchange of hydro and wind power between two advanced energy markets.
- Viking Link: A 765 km interconnector between Denmark and the UK is strengthening offshore wind integration and lowering prices through grid flexibility.
- NordBalt, Estlink, SwePol: These undersea links in the Baltic region have enhanced cross-border energy cooperation among Sweden, the Baltics, Finland, and Poland.
- EuroAsia Interconnector: This 1,208 km HVDC link between Israel, Cyprus and Greece was expected to become the longest and deepest interconnector in the world. However, the seabed exploration has been blocked by Turkey and the project is currently suspended.
- Sun Cable: This project aimed to export solar energy from Australia’s Northern Territory to Singapore but was canceled in early 2024.
These initiatives are not isolated experiments. They show a growing global interest in inter-regional energy exchange. Many of these projects are shaped by climate goals, geopolitical shifts, and the need for resilience in an era of increasingly extreme weather patterns.
Meanwhile, the proposed NATO-Link, a transatlantic cable connecting Europe and North America, would offer advantages like peak demand balancing across time zones and reduced dependence on fossil fuel imports. Investors and developers have organized into the NATO-L initiative (https://nato-l.org/), doing their best to turn the NATO-Link idea into a concrete project by bringing together technical experts, private capital, and government stakeholders.
CleanTechnica has noted that the economics of a globally connected grid are becoming increasingly favorable. Their analysis shows that long-distance HVDC transmission between continents can match the cost of building local renewable energy sources plus storage.
So, while the global super-grid may still be only a long-term goal for now, the building blocks to make it a success are starting to fall into place.
The Case for Going Bigger
Though there has been plenty of progress in regional interconnection, most electricity today is still consumed within national borders. According to the UN, international electricity trade made up just 2.8% of total supply in 2021, about 809 TWh globally. This means that most countries still rely heavily on domestic generation and is certainly a missed opportunity, considering that the world we live in is becoming increasingly reliant on intermittent wind and solar energy.
But a global supergrid could turn this missed opportunity into a win for everyone. If electricity grids are linked across time zones and continents, countries could align peak renewable supply with peak demand. So the solar power that is generated in the early afternoon in Morocco could be used to meet the evening demand in the UK. And wind from the North Atlantic would be used in North America while Europe sleeps. Seasonal differences would be smoothed out. For example, the Sahara’s sunny winters can counteract Scandinavian short winter days.
It’s exactly these east-west and north-south dynamics that can make renewable energy more efficient. Instead of curtailing when local supply outpaces demand, clean electricity would be shipped somewhere else, also reducing the need for fossil-fuel backup.
Of course, there’s also a strategic and geopolitical argument for the global supergrid. With energy interdependence and shared investment in resilient infrastructure fostered between nations, the risk of conflict over energy access would be reduced, or would at least become more local. Ember notes in its analysis of the proposed NATO-Link that a transatlantic interconnector could help fortify energy security, balance grid stress across regions, and improve price stability for both Europe and North America.
So maybe the question shouldn’t be “Can we build it?” but: “Can we afford not to?”
Why It’s Still So Hard
You might be asking yourself why the global supergrid isn’t being planned out and put into action as soon as possible. Unfortunately there are some technical and logistical hurdles that still stand in the way of the dream of global energy interconnection. Many supporters argue that energy interdependence will foster peace and efficiency, just like the EU once envisioned economic ties as a path to stability. Critics, however, worry that relying on distant energy suppliers could introduce new forms of geopolitical leverage.
Also, even though HVDC cables are technically feasible, they are challenging to deploy and maintain, especially if they are undersea. Maintenance in remote environments, such as beneath the ocean, raises additional questions of resilience and repair time. The security of these cables is also being called into question, especially since several undersea cables in the Baltic Sea were severed in suspected Russian sabotage. Infrastructure that crosses borders is vulnerable not just to legal fragmentation and shifting political alliances, but also to intentional damage. Undersea cables are increasingly seen as critical infrastructure and potential targets in a world of rising geopolitical tensions.
The interconnecting of regions and continents does not come cheap. If we want a global grid, trillions would need to be invested. Projects like the Xlinks Morocco-UK interconnector, which promises access to abundant solar energy, are facing increasing project costs, from the previously estimated £20 bn to £22-24 bn, thanks to economic pressures. While analyses do suggest that such projects would be cost-effective in the long run, the upfront capital would be high; for instance the UK recently announced that it would not provide funding for Xlinks. However, some investors who truly believe in projects, like NATO-Link and Xlinks, are organizing and actively lobbying.
The Road Ahead: Bold Vision or Regional Focus?
So how realistic is a global supergrid? While the dream of a globally interconnected electricity system is still inspiring energy thinkers, many experts argue instead for regional supergrids, which would be a more achievable stepping stone.
But whether or not we actually do connect the entire world into one giant power grid, it seems that cross-border electricity trade is indeed unavoidably the future. The IEA emphasizes the growing importance of cross-border electricity trade to support energy security and affordability, particularly as variable renewables scale up. The EU aims for all member states to reach 15% electricity interconnection capacity by 2030, and as of early 2025, 14 countries have already met this target. However, progress isn’t uniform. Spain and Portugal still remain below 5%, due to limited grid connections with France.
Regional organizations, like Europe’s ENTSO-E, may provide more politically and technically feasible ways to deepen integration before attempting anything global in scale. These systems still offer significant benefits like smoothing prices and improving grid resilience.
Ultimately, whether the grid of the future is global or regional, it must be smarter, more secure, and more collaborative. As all nations try to tackle climate change and energy security, sharing electrons will become just as valuable as sharing values.
