Iceland's volcanoes could power the UK: but at what cost?

The government is considering the possibility of using geothermal energy generated in Iceland to power homes in the UK through sea-floor cables that would link to a Europe-wide supergrid. But what are the technical and political implications of creating a new European supergrid?

The idea of introducing new interconnector cables over the next decade to link the UK to a Europe-wide supergrid — that would also harness wind and wave power of northern Europe with solar projects in Southern Europe and North Africa — has been backed by the UK’s Prime Minister. There are two existing international interconnecters linking Britain to the Netherlands and France but nine more are at various stages of development, including the UK-Iceland interconnector.

In theory it’s possible to pump low-carbon electricity from Iceland to the UK to meet up to a third of the UK’s average energy consumption through thousands of miles of high-voltage copper-cable that would be placed along the ocean floor.

Interconnector cables can be laid at 30km per day but for the plan to work, the cable would have to be by far the longest in the world - between 1,000 and 1,500km - with each kilometre containing 800 tonnes of copper. While this would undoubtedly be a huge engineering project - with costs likely to be far greater than the £500m Britain-Netherlands interconnector - it could still be completed relatively quickly.

The financial costs are one thing but many people may believe that we should not be looking overseas to meet Britain’s energy demand. The UK used to be fairly self-sufficient in oil, gas, and coal, but that has changed recently as the North Sea oil and gas reserves near depletion and coal’s damaging effects to the environment are recognised. While there are other energy sources available in Britain — such as wind and solar — their cost effectiveness remains uncertain. 

Jonathan Farr, a DECC spokesperson, told The Engineer: ‘The idea of the Iceland project is to ensure we’ve got access to energy when we need it. The UK has lots and lots of power — enough to meet demand — but it’s the intermittency [of the renewables] that is a problem.’

Farr used the example of UK homes in the middle of winter when someone boiling a kettle in a fully heated house with the TV on, compared to 3am in the middle of summer when next to no energy is being consumed. ‘Now is it worth having all that capacity built and ready standing, if elsewhere it’s just there and available through a pipe?’ Farr asked.

The ambitious idea of pumping energy to the UK will be discussed in greater detail in May when Energy Minister Charles Hendry visits Iceland to discuss connecting the UK to its abundant supply of geothermal energy. Hendry believes that a web of interconnector cables ending the energy isolation of the British Isles will keep household energy bills down, as they would allow access to the cheapest energy at any particular time.

The general idea of pouring surplus renewable energy reserves into one big European pot is a sensible one. But the project will only become a reality if sufficient private funding can be located and governments across the continent can agree on the appropriate terms and conditions for investment and exploitation.