Iceland may soon spread its vast wealth of geothermal energy to the UK. But how can two islands separated by more than 1,000 km of ocean share electricity? The answer lies in undersea high-voltage cables.

UK Energy Minister Charles Hendry is set to visit Reykjavik this month to discuss the possibility of burying miles of undersea electricity cable to connect the two countries' electricity grids. If built, the cable would be the longest interconnector in the world.

According to the Guardian, this project would be part of the Europe-wide supergrid, an initiative to connect renewable energy sources and meet clean energy and emission reduction targets. Ideally, Scottish wind power, African and German solar power, Belgian and Danish wave power, Norwegian hydropower and more will be dispersed via smartgrid transmission lines. The UK already has two interconnectors via France and Norway, and nine additional cables are in the works. If all goes well and the supergrid is completed, these interconnectors could help to satisfy one third of the UK energy demand. 

The UK hopes to cut down on fossil fuel imports and secure its energy independence as several nuclear power plants are to be decommissioned in the next decade. The country is also aware of possible intermittency issues with its massive wind developments and hopes this project will secure sustainable, 24/7 geothermal power. According to the Guardian, this interconnector would also allow for excess wind power to pump water into storage lakes, and when electricity is needed, the water would be released and flow through turbines, further establishing “backup” energy storage.

“Interconnectors are an incredibly effective way to counter the argument that you need to back up each gigawatt of wind with a gigawatt of gas — they quite clearly show you do not,” said Hendry to The Guardian. 

Building interconnectors is an expensive endeavor — the 260-km Britain-Netherland interconnector, opened in 2011, came in at a cost of £500 million (US $807.9 million). But even though they are costly to build, some analysts argue that interconnectors are the cheapest method to support wind intermittency without building a power plant. And interconnectors also allow for power to be sold and purchased when supply is high or low.  

Not to mention there is concern about the supply of raw materials needed for each connector — each kilometer of cabling requires 800 tons of copper, an earth metal that is becoming scarce and expensive. 

Despite these concerns, both countries are eager to move forward with the plan. Said Hendry, “We are in active discussions with the Icelandic government and they are very keen.”

Image: sergioboccardo via Shutterstock

"Interconnectors are an incredibly effective way to counter the argument that you need to back up each gigawatt of wind with a gigawatt of gas — they quite clearly show you do not." -- Charles Hendry, UK Energy Minister