Britain's power imports cost €1.7 billion less than burning its own gas

Since 2022 Britain has gone from selling power abroad to buying it, through undersea cables to France, Belgium, the Netherlands, Denmark and Norway. Power on the Continent, much of it from nuclear plants, hydro dams and wind farms, has often cost less than making it at home in gas plants. Now those imports face a challenger of their own. On 21 October the government approved Shell's Jackdaw gas field in the North Sea, arguing that more British gas makes Britain less dependent on imported fuel. The government expects Jackdaw to raise British gas production by about 6% at its peak, and it links taxes from North Sea fields to its new Energy Wealth Fund. Earlier this month, in "Britain pays more for power than most of Europe, and buys a tenth of it from abroad" (October 2026), we reported that most of those imports come from France, and that the price gap on them is earned by the cable owners and the traders who book space on the cables. Jackdaw's approval changes the question from where Britain's energy comes from to what it costs. Would making more of Britain's power from British gas cost British buyers more or less than the imports it would replace?

What we compared

We compared the power Britain imported through its cables from five neighbours (France, Belgium, the Netherlands, western Denmark and southern Norway) with what a British gas plant would have spent on fuel and carbon to make the same power, between 1 January and 20 October 2026. Results are shown separately for midday and the evening, using Central European Time, the clock on which the Continent's power exchanges set their prices and an hour ahead of UK time: midday runs from 11:00 to 15:00 and the evening from 18:00 to 22:00. We split the day this way because Europe's power price follows the sun and the evening peak, not the calendar. At midday, solar panels across the Continent push prices down. In the evening, when the sun has set and demand is high, the most expensive plant needed to meet demand sets the price for every megawatt-hour traded in that hour, and that is usually a gas plant.

For the neighbours, we assess each country's price separately at midday and in the evening, in the price zone where its cables land. A British gas plant's fuel and carbon cost, by contrast, is set once a day by the price of gas and carbon allowances, so it is the same at midday as in the evening. We therefore use that single daily cost, Ember's estimate based on Dutch TTF gas and EU carbon prices, as the benchmark against every neighbour in both periods.

In our comparison of Britain's imported power with power from British gas plants in this report, we focus on two measures because they capture different sides of the cost:

Average day-ahead price measures what a megawatt-hour cost in the zone where it was made, the price generators abroad were paid when they sold it the day before delivery. It reflects how much power each neighbour has to sell in that hour and what its most expensive plant costs to run. For Britain's imports, it depends heavily on what each neighbour generates its power from: nuclear plants in France, hydro dams in Norway, wind in Denmark, and more gas in Belgium and the Netherlands.

Share of hours cheaper than gas shows whether a neighbour's power beat a British gas plant hour by hour, not just on average. It counts the hours in each period in which the neighbour's day-ahead price was below a gas plant's fuel and carbon cost on that day, and so assesses whether importing in those hours was cheaper than burning gas at home. It decides the question Jackdaw raises: in how many hours British gas could have made Britain's power for less than its sellers abroad were paid.

A neighbour's power can look cheap on average and still lose to gas in the hours when Britain needs it most. The average price shows what Britain's imports cost overall, while the share of hours cheaper than gas shows how often, during an ordinary day, importing beat burning gas at home. That difference is at the centre of the comparison between Britain's imports and its own gas, and of who earns from it: the generators and cable owners abroad, or a gas field in the North Sea. Before the day is split in two, the chart below shows the whole period month by month: the price of the power Britain actually imported, where it was made, against what a British gas plant would have spent on fuel and carbon in the same hours, both weighted by the power that flowed. Imports were cheaper in every month. The gap per megawatt-hour was narrowest in January and widest in April, and May saved the most money, because more power flowed. The gap held even as gas prices climbed from July.

The evening

The monthly chart answers the question for the year as a whole. For British suppliers that buy power from generators abroad, and for Shell and the government as they weigh up Jackdaw, what matters next is in which hours imports still win. The chart below sets each neighbour's average day-ahead price at midday and in the evening against a British gas plant's fuel and carbon cost, and counts how often, hour by hour, each neighbour's price fell below it.

Those dots show what power cost in each neighbour's market after dark. A British gas plant's fuel and carbon cost does not move with the hour, because it is set once a day by the price of gas and carbon allowances, while the neighbours' prices rise once the sun has set. Weighted by the power each neighbour sent Britain, the evening price was €88 per megawatt-hour higher than the midday price, which put the evening average just above a gas plant's cost.

The power Britain actually bought after dark is a different average. Generators that can choose when to sell hold their power back for the hours when prices peak, and cable owners auction space on their cables to traders, who move power to whichever end of the cable pays more. Traders therefore bring power into Britain in the evening hours when it is cheap at the other end and hold back when it is dear. Counting only those hours, it cost €120.6 per megawatt-hour where it was made, against €133 for a gas plant in the same hours: the power Britain bought after dark still beat gas, by a far narrower margin than at midday.

On the share of hours cheaper than gas, the same split appears. Weighted by the power each neighbour sent Britain, their power was cheaper than a gas plant's fuel and carbon cost in 93% of midday hours and 44% of evening hours. The measure counts every hour in which a neighbour's day-ahead price fell below that day's gas plant cost, so it reflects the cheap hours and the dear ones, not just their average. In the evening, France and Norway still hold their own against a British gas plant. Belgium, the Netherlands and Denmark fall away, because once the sun has set their own gas plants, or the most expensive plant needed to meet demand, set their price.

France and Norway

Two of Britain's five neighbours carry its imports through the evening, France and Norway, and they do it in different ways.

Our analysis covers the five continental neighbours whose prices are in our archive. The island of Ireland is left out: Britain sells power to Ireland rather than buying from it, and our archive does not cover Ireland's single market. The chart below covers every hour of the year in which power flowed into Britain, not just midday and the evening, and shows how much each neighbour's power saved Britain against what a British gas plant would have spent on fuel and carbon to make it. A long bar comes from selling a lot of power as much as from selling it cheaply: France's bar is long mainly because France sent Britain so much. The flows and prices come from Energy-Charts and Elexon, and the gas plant cost from Ember.

France's lead is new. In 2022, with many of its reactors offline for repairs, Britain sold power to France; this year France sent Britain most of the power it imported. EDF's nuclear plants cost little to run once built and run all day, and they sell to British suppliers through the two IFA cables, owned by National Grid and RTE, France's grid operator, and through ElecLink, Getlink's cable through the Channel Tunnel.

Norway's hydro plants hold their water back and sell when Britain's price peaks, so the North Sea Link, owned by National Grid and Statnett, Norway's grid operator, is the only continental cable that carries more power into Britain in the evening than at midday. That makes Norwegian power the dearest of the five on average, and the hardest for British gas to undercut after dark. Ofgem regulates the link, like Nemo and Viking, under its cap-and-floor regime: when Norwegian hydro sells into Britain's evening peak, earnings above an agreed cap go back to British consumers through their bills.

The other three are midday suppliers. Belgium has shut most of its nuclear reactors since 2022, and although its parliament repealed the nuclear phase-out in May 2025, gas plants still set its evening price. On Nemo, which National Grid owns with Elia, Belgium's grid operator, and on BritNed, owned with TenneT, the Dutch grid operator, power flows into Britain at midday and often out of it in the evening, when prices there rise above Britain's. Denmark runs mostly on wind and solar, so Viking, the newest link, opened at the end of 2023 and owned by National Grid and Energinet, is cheap while the sun shines and the wind blows.

How large the lead is

The table puts a size on each lead, setting each neighbour's price against a British gas plant's fuel and carbon cost at midday and in the evening, and counting the share of hours each side was cheaper. At midday the leads are wide everywhere, widest in France, where EDF's nuclear plants undercut gas by €98 per megawatt-hour.

In the evening they narrow to almost nothing. Power through the North Sea Link undercuts a gas plant by only €2.5 per megawatt-hour, and French power and a gas plant roughly split the evening hours between them. For a British supplier, that is the margin imports have to lose before British gas becomes the cheaper choice: wide at midday on every cable, thin in the evening even on the two best.

What this means

Jackdaw's case rests on the hours in which British gas would have been cheaper than the power Britain imported. To find them, we ranked every imported hour by how much making that power in British gas plants instead would have saved, and replaced imports with gas in that order, starting with the hours in which imports were dearest against gas. The saving peaks once about one imported megawatt-hour in seven has been replaced, at €92 million. Beyond that point every further unit of gas costs more than the import it replaces: by the time a little over a third of the year's imports have been replaced, the saving is gone, and replacing all of them would have cost Britain €1.7 billion more than buying them.

For a British supplier, imported power is sold at the British price, so it pays the same whether the power was made in France or in Britain. What the imports save is the money Britain would otherwise have spent on fuel and carbon allowances, and that money goes instead to the generators abroad and to the cable owners and traders who move the power. Suppliers and traders can build on that by booking space on every cable at midday and on the cables to France and Norway in the evening. Cable owners such as National Grid can build on it by adding links: NeuConnect, a cable to Germany, is due to open in 2028, and in November 2024 Ofgem approved in principle LionLink and Nautilus, offshore hybrid links that connect offshore wind farms to Britain and to the Netherlands and Belgium.

Imports' lead is not fixed, though. Imports are unlikely to beat British gas more often in the evening in the near term: after dark the most expensive plant needed to meet demand sets the price on the Continent, and in Belgium and the Netherlands that is usually a gas plant, which new nuclear plants and offshore wind farms will take years to change. And prices on the Continent are climbing towards Britain's. In our October 2026 report, "Britain pays more for power than most of Europe, and buys a tenth of it from abroad", we found that the North Sea Link carried less power this year than last, because southern Norway's price rose towards Britain's, and that the gap between Britain and France almost closed in September and October. Jackdaw's gas, about 20 TWh a year at its peak, is a small addition to the gas Britain burns in its power stations and ships in from Norway's pipelines and American LNG tankers. Because it sells at the market price, as its output grows it will move money to a North Sea field and, through its taxes, to the government's Energy Wealth Fund, rather than lower the price British buyers pay for power. British suppliers, traders and cable owners need to double down on the hours and cables where imports beat gas, midday on every link and the evening on the cables to France and Norway, and make that saving the central case for buying power from abroad.

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Methodology

Flows are hourly physical flows between Great Britain and France, Belgium, the Netherlands, western Denmark and southern Norway, from Energy-Charts, for 1 January to 20 October 2026. An imported hour is one in which a country's cables carried power into Great Britain, and the imported volume is the sum of those flows. Prices are hourly day-ahead prices for the zone at each end of each cable, from the European power exchanges via Energy-Charts. Great Britain's prices are Elexon's market index, converted from pounds at the European Central Bank's daily rate. Denmark is its western zone, DK1, where Viking lands, and Norway is the southern Norway zone of the North Sea Link. Each imported megawatt-hour is valued in three ways: at the price in the zone where it was made, at the British price in the same hour, and at the fuel and carbon cost of a gas power plant on the same day. That cost is Ember's short-run marginal cost for gas, which is based on Dutch TTF gas and EU carbon prices. What Britain paid sellers abroad is each hour's imported volume multiplied by the price where the power was made, added up. The gas cost is the same volume multiplied by the gas plant cost, and the saving is the difference between the two. Average prices by neighbour and by month are weighted by the volume imported in each hour. The gas plant cost is weighted the same way when it is set against imported power, which puts it at €134 per megawatt-hour across all imports and €130 in the hours France supplied; set against a zone's price across all hours of a period, it is a simple average of days, €135.5. Group averages in the midday and evening comparison are weighted by the power each neighbour sent Britain in those hours. Midday is 11:00 to 15:00 and evening 18:00 to 22:00, Central European Time. The share of hours cheaper than gas counts the hours in each period in which a zone's day-ahead price was below the gas plant cost. The replacement scenario ranks imported hours by how much would be saved by making that power in British gas plants instead, and replaces them in that order, largest saving first. It assumes British gas plants had spare capacity to run. British plants also pay the UK carbon price and Carbon Price Support, which Ember's figure leaves out, so our gas cost understates theirs and the saving from imports is, if anything, larger. Gas supply figures are from the Department for Energy Security and Net Zero's Digest of UK Energy Statistics 2026, tables 4.1.1 and 4.5. Jackdaw's peak output is our estimate. We applied the government's expected rise in British production at the field's peak, from its announcement of 21 October 2026, to British gas production in 2025.