Despite claims that Britain is on the brink of blackouts and amid forecasts of a looming cold snap, all is calm inside the room where a score of engineers and analysts work to ensure the lights stay on.
Below a huge, illuminated map of the UK’s electricity network and myriad displays, a gentle hubbub of conversation washes over the desks of the control centre in Berkshire, the chief site of three run by National Grid.
“It should look like a swan paddling across the pond,” says Nick Easton, one of the grid’s power system managers who sit at the back of the windowless room with six screens of their own, overseeing three teams around the clock in eight- and 12-hour shifts.
The day is a relatively easy one for the team. For every 1C the temperature falls, electricity demand goes up 0.5 gigawatts, and on this evening – in the first week of February – demand is expected to peak at 48GW compared with a typical 52GW on a winter evening. However, the calm on show belies the huge changes in the energy market that serves the grid.
The way that the UK maintains its electricity reserves is evolving, with a new system for subsidising backup power being brought in next winter. Last Friday £378m worth of contracts were awarded for the capacity market, most of which will be paid to old gas, coal and biomass power stations that will be ready to provide power at short notice if there is a surge in demand or dip in supply.
But the sources of the UK’s power are changing fast, from a small number of fossil fuel and nuclear power plants to a greater reliance on renewable providers such as windfarms, backed up by gas power plants and undersea power lines connected to continental Europe and Ireland. The grid says the transformation does not make its job harder – just different.
“The summer of 2015 was the last time we ran the grid in the summer the way we had done for the last 70 years, with large generation churning out our everyday power,” says Duncan Burt, who manages the operation of the grid from day to day. “The growth in solar and the continuing reduction in demand meant 2016 really was fundamentally different, the first year of the new power grid.”
Solar power has grown from a tiny presence before 2010 to more than 11GW out of the UK’s total capacity of about 80GW, driven by subsidies for householders and the construction of large solar farms.
Burt says the intermittent and sometimes unpredictable power from all those solar panels has not increased the cost of fine-tuning electricity supply and demand. The grid spends £850m each year to keep the two in balance, paying power generators to fire up in the face of an unexpected event or a large power user such as a factory to switch off.
An increasing amount of that power is also coming from windfarms, in particular from Scotland. Two transmission lines running alongside the M6 and M1 have been upgraded in recent years to export wind power to England, and capacity will leap again when a new undersea cable carrying more Scottish renewable energy comes ashore on the Wirral, Merseyside, later this year.
“It’s huge, a tripling in the capability in the network’s capacity [from 10 years ago], and that’s because of the enormous amount of wind in Scotland,” says Burt.
The other big swing last year was away from coal, as three major power stations closed in the face of lower gas prices and a carbon tax. For the first time, there were several days without coal power, and gas and solar took up much of the slack.
“The grid was fine. Gas or coal doesn’t necessarily feel any different, but it’s a big moment, a watermark. We’re really comfortable about coal going,” says Burt, referring to the UK government’s pledge to phase out coal by 2025.
What does worry him is the threat of Britain’s ageing network of nuclear power stations closing down from the middle of next decade as it reaches the end of its life. “That’s very much something we’ll watch closely. If nuclear went for safety [inspection] reasons, we would get weeks rather than years of notice,” he said, pointing to the nuclear outages in France this winter because of safety checks.
The changing way the UK generates electricity is throwing up some unusual market quirks too.
On weekends last year when electricity demand was low and solar generated a lot of power, wholesale electricity prices went negative. Under this scenario, instead of power station owners selling their electricity to the energy companies who supply UK homes and businesses, the generators actually paid the suppliers to take their power. It is not an an attractive situation for generators.
“We think that if solar keeps growing, by 2020 [negative prices] will be a very regular occurrence in the summer and we want the market to be ready to balance that,” says Burt.
His answer to that balancing challenge is to persuade big industrial and commercial energy users – water companies, supermarkets, the NHS – to shift their power consumption to the times of day when the sun is shining, the wind is blowing and demand is lower. “What you really want to do is consume power when the renewables are there, and you need to price to signal that.,” he says.
But while Burt must juggle those longer-term concerns, the control centre has more pressing problems right now: balancing the supply and demand of electricity, second by second.
The grid has not called on any of its emergency 3.5GW of capacity this winter, which has seen temperatures on a par with the long-term average. But the Met Office expects south-easterly winds later this week to bring drier, colder weather, with the possibility of snow on the east coast. Half of the UK’s electricity interconnector – or sub-sea cable – to France is also out of action and being repaired following storm damage last year, adding extra pressure.
Easton, who is not on shift and looks more relaxed than the control centre manager, admits the job carries a lot of responsibility.
“Sometimes you stop and think: ‘I’ve got the nation’s transmission systems in my hand’ – and the implications of a blackout are quite profound. But you don’t necessarily stop to think about that. You have a role to do, and you’re surrounded by knowledgeable people.”
