A fire broke out on 15 September at a facility that is part of the UK’s biggest electricity cable to continental Europe, causing wholesale power prices to spike and raising concerns over squeezed energy supplies in the coming months. So is the UK heading for a winter energy crisis? Here is what you need to know.
What has happened?
The fire occurred at a converter hall in Sellindge, Kent, which takes DC electricity running along the 2-gigawatt Interconnexion France-Angleterre (IFA) interconnector from France and converts it into AC power that UK energy networks can use. The fire was still going last night, but is now out. National Grid, which runs the interconnector, says it has a team at the site carrying out an early investigation into the damage. The cause of the blaze isn’t yet known, the company says.
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What does this mean for UK electricity supplies?
IFA is the oldest and biggest interconnector to the UK, and has two cables with 1 gigawatt of capacity each. These types of long-distance copper cables provide the UK, and other countries, with flexibility in a world where electricity supplies are increasingly variable because of the growing uptake of wind and solar power. In recent days, the UK has largely been using IFA to import rather than export electricity.
Half of the interconnector’s capacity, 1 GW, was already offline for planned maintenance. The other 1 GW that was running until yesterday is now out of action, as the fire is believed to have damaged converter equipment at Sellindge. National Grid says that half the capacity isn’t expected to return until March next year. So far, the company has said that the half out for maintenance should be back on 25 September.
But there is a big question mark over that, as the estimate was made while the fire was still going – it is possible that damage to converter hardware will render the full 2 GW unusable until next March. In 2016, half of IFA’s capacity was taken offline when a . That damage took several months to repair.
Why does this matter?
Losing 2 GW of capacity almost halves the 4.3 GW margin of spare capacity that National Grid . “It puts the [Great Britain] market in a risky position for the winter and especially if we suffer from periods of low wind and cold temperatures,” said analysts Enappsys in a statement.
“It’s a security of supply issue,” says Tom Edwards at market intelligence firm Cornwall Insight. “If we’re relying on older power stations, especially coal or ageing gas plants, those are maybe more risky.”
The short-term impact will be on wholesale power prices, says Edwards – the cost your power company pays to generators in order to supply electricity. Wind power output in recent days has been very low, supplying just 4.4 per cent of electricity across Great Britain in the past 24 hours. Normally, it is much higher: wind turbines .
Edwards says the power stations National Grid will now have to call on to fill any gaps in supply will be “much more expensive”. For example, the Ffestiniog pumped hydro plant in Wales was charging £6000 a megawatt-hour at times yesterday, while coal plants Ratcliffe and West Burton A, both in Nottinghamshire, were charging £3000 to £4500 per megawatt-hour. A more typical price is £50 per MWh.
And what about how green the grid is?
Edwards says another short-term effect will be higher carbon intensity, a measure of how much carbon dioxide is emitted per unit of electricity generated. Coal power, a backbone of the UK electricity grid only a decade ago, has almost been phased out and most days this year hasn’t been used at all. But in the past 24 hours, it has supplied 3.6 per cent of electricity in Great Britain. The carbon intensity of the grid is . That is a far cry from the 50 g CO2/kWh the , and 2g CO2/kWh by 2050.
What is going on with UK energy prices more broadly?
Energy prices in the UK had already been soaring even before the fire knocked out the interconnector. Average daily power prices in the past fortnight have been eight times the 2019 average, according to Enappsys. The hourly price for the day ahead hit its highest ever level yesterday, at £2500/MWh. Last winter, a “normal” price was around £50 per megawatt-hour, though the UK did see price spikes of up to £1500/MWh, says Edwards. “Obviously, there’s no wind at the moment and the crazy prices are because there’s a global shortage of gas,” he says.
Gas supplies have been hit by various outages this year, including at Norwegian gas fields. But a full-blown crisis is unlikely. Edwards says the extremes of current prices will be temporary: “The wind should be back [soon]. This won’t last forever.”
Does this incident imply the UK is too reliant on interconnectors, or does it need more?
The UK has a , connected to Belgium, France, Ireland and the Netherlands, and Great Britain has a 500 MW internal link with Northern Ireland. Much more is planned. A new 1.4 GW one connecting the UK to Norway’s hydropower is due to be fully operational next month. Another 1 GW will be added next year via one run through the Channel Tunnel. Further ones will follow to Denmark, in 2023, and Germany, in 2025.
“[The IFA outage and fire] won’t necessarily be as big a deal in future when we have more cables,” says Edwards. And it won’t just be about giving the UK more import capacity. According to some National Grid scenarios, by 2025, the UK will regularly be a net exporter because of its growth in offshore wind farms. “Interconnectors are important because they supply flexibility” says Edwards. “Any diversity we can get in our energy supply is good.”
