In addition to storage, for significant decarbonization to take place, it is imperative that energy resources can be moved from where there is a surplus of power, to where it is needed.
That is what is increasingly the case in Europe and the UK as described here. One might suppose that with the UK leaving the EU, there would be less power interconnectedness. The reverse is the case.
"Britain’s economic and political ties to Europe may be fraying, but a growing web of undersea electrical cables binds the nation’s vital power system and its clean energy aspirations to the continent.
The longest and most powerful of these cables was recently laid across the North Sea, from a hydroelectric plant in Norway’s rugged mountains to Blyth, an industrial port in northeast England."
"The twin cables, each about five inches in diameter, can carry enough power for nearly 1.5 million homes.
The idea is to use the cable to balance the two nations’ power systems and take advantage of differences between them. In the broadest terms, Britain wants to tap into Norway’s often abundant hydropower, while the Norwegians will be able to benefit from surges of electricity from British wind farms that might otherwise be wasted.
The rapid growth of renewable energy sources like wind and solar, whose output varies with the breeze and sunshine, makes such sharing increasingly essential, experts say."
“Interconnectors across borders on a continent like Europe are a prerequisite” to enable societies to run on renewable energy, said Hilde Tonne, the chief executive of Statnett, the Norwegian electric grid operator that is a half-owner of the cable, along with Britain’s National Grid.
The ability to share electric power, to import or export it as needed, she added, is crucial to “moving from fossil fuels to an energy mix that is more and more weather based.”
 "Besides the cable to Norway, National Grid manages undersea links to France, Belgium and the Netherlands. A 2 billion pound ($2.7 billion) interconnector to Denmark is under construction, in partnership with the grid operator there."
"For undersea cables, “there is no limitation when it comes to length,” said Bjorn Sanden, a technical director at Nexans, a Norwegian company responsible for a large portion of the cabling on the link between Britain and Norway. Projects under discussion, like a 2,600-mile undersea link that would take solar power from Australia to Singapore, are theoretically feasible, if the economics can be made to work, he said."
Still, there are still issues to be worked out, technical, political, commercial and social.
"Britain’s plans for the North Sea could be made more complex by the country’s uneasy ties with its former European partners. It has been excluded from a European power pricing system, making its interconnectors more cumbersome to use, said Chris Matson, a partner at LCP, a consulting firm."
"Also, coastal communities have raised objections to the electrical equipment necessary at both ends of cables. To avoid large losses of power over long distances, the electricity must be converted from alternating current to direct current, and then back again at the other end."
"If Britain does move much of its electrical system offshore, power could be brought to land at a few carefully chosen sites rather than at many locations, as has occurred."