- How do gas power stations work?
- How many people does it take to operate each £1m jet engine turbine?
- What are the challenges when the temperature drops below zero?
Join our intrepid reporter Lauren Bravo on her visit to British Gas’ Peterborough Power Station to interview the team and to take a look around the plant.
They’re the machines that power our country – but what actually goes on inside a gas-fired power station?
To most of us, it’s a mystery – so when I arrive at Peterborough Power Station, I’ll admit that part of me half expects to find a giant bonfire. But as Generation Manager Dave Theakstone shows me, the reality is far more sci-fi: two huge gas turbines surrounded by a protective wall of carbon dioxide, reaching 14,000 volts and temperatures of up to 1,100 degrees.
Opened in 1993, Peterborough power plant has evolved a lot over the past 23 years – once an all-action 24/7 machine with 56 staff, it’s now a lean on-call service tailored to meet the fluctuating needs of the nation.
Generating bursts of on-demand electricity
How does it work? “Put simply: we use a gas turbine, which is essentially a jet engine, to spin a big magnet, which creates electricity,” says Dave. If it ran all day, the power station could power about 50,000 homes on average – which, neatly, is about the size of Peterborough.
But instead it operates as part of National Grid’s Short Term Operating Reserve (or ‘STOR’, because everything in the world of energy has an acronym), ready to spring into action within just 20 minutes every time extra power is needed to top up the supply. As Dave explains, “We provide National Grid with a comfort blanket, knowing we’re here in the event that anything happens.”
And in the vast and complex picture of the UK’s power supply, a variety of things regularly do happen – planned outages, technical problems, or just a larger than usual demand. Peterborough was last called on four days ago, for two sessions lasting just two hours each.
A model of efficiency
Is this drive for instant energy just another example of our impatient, on-demand culture? Perhaps, but Dave considers it a good thing. “Actually the way we run now is more environmentally friendly than in the past,” he says. “We’re providing energy when people need it.”
“As we’ve seen a drive for efficiency – LED lighting, smarter heating and appliances, better insulation, incentive schemes, flexible working – the demand for power has fallen.”
Peterborough is now paid by National Grid on a 12-month contract, to be ready to spring into action as soon as a call comes through.
“It’s actually an alarm, though we still call it ‘a call’ because it used to be a telephone call – like the Batphone,” says Dave. And when that call comes in, I ask eagerly, is it all hands on deck? How many people do they need to operate that £1m jet engine turbine?
Keeping busy between power generation
“When I tell people I work at a power station, they always say ‘like Homer Simpson!’” laughs Dave. But far from sitting around guzzling doughnuts, Peterborough’s staff of 18 has plenty to fill their on-call days.
“The morning starts at around 6am with site checks,” he tells me. “We have auxiliary pumps whirring away all night, which means the machine can start up quickly. We look at market data, we talk to the traders, we ask what the power demand is, and do preventative maintenance. There’s a lot of checking, testing and paperwork to do. We make sure all of that is done and dusted and we’re keeping compliant, because little things can cost us big.”
He isn’t exaggerating. A whole gas turbine at Peterborough costs around £1 million, and just one of its hefty metal blades costs upwards of £10,000 – up to about £60-70,000 each for the largest. I try to lift one, and fail.
“After so many startups and shut downs we need to have them serviced and checked, like a car MOT. Even a tiny little crack could cause an issue,” explains Dave. Two years ago one of those £10,000 blades snapped off, while spinning at a colossal 3,000 rpm. “Everything was safely contained inside special casing, but of course we had to contact National Grid and tell them. They’re quite understanding though!”
Keeping the lights on
Stations like Peterborough are key to National Grid’s work, finely balancing the country’s energy supply with the real-time demand for power to make sure we never have to worry about blackouts. “We maintain the site with two members of staff for 24 hours a day – even Christmas Day, you’ll be pleased to know,” says Dave. “So if there’s an incident, you can still cook your turkey.”
The toughest challenge Dave remembers in his own career was Princess Diana’s funeral (“during the three minute silence, everything stopped… and then started again”), but not everything is as predictable. “I’ve worked at sites that have been struck by lightning a couple of times,” he says. “They say that lightning never strikes twice… unless you’re in Hull.”
Winter is coming… which means greater demand for energy
On the day I visit in October 2016, there’s some good news: National Grid’s Winter Outlook Report is released, announcing a healthy new capacity margin (the amount by which energy available will exceed demand) of 6.6% compared to last winter’s “tight but manageable” 5.1%, although this is still much less than the UK has had in the past.
This is due in part to £122m of investment this year in Supplemental Balancing Reserve contracts, which pay old coal power stations to be on standby, just in case. Although Centrica (British Gas’ parent company) has not made the investment decision yet, it has recently had planning permission granted to build a new back-up gas plant at Peterborough, right next door to this one.
But while a cold winter is a challenge in terms of the energy our homes guzzle up, the weather can also present much more immediate problems. “One December I got a phone call at 4am saying ‘Dave, everything’s frozen’. It was -12°C and had snowed so deep I had to park a mile away from work and walk there in my wellies. We had to go out with heat guns to thaw everything and get the turbine running. But we did it.”
The future for gas
Thanks to green targets and investment in renewables, coal-powered electricity is being swiftly phased out in the UK – but will gas follow suit?
“Well, it’s a fossil fuel and there’s not an endless supply. But it’s a cleaner fossil fuel,” says Dave. “It’s that classic trilemma: security, affordability and sustainability. Energy has to be affordable for the companies producing it, as well as for the customers. We might not be able to be absolutely squeaky clean yet, but we’ll be as clean and as efficient as we can – it’s a work in process.”
That adaptability is perhaps the biggest surprise of my visit to the power station. Despite millions of pounds’ worth of hulking equipment, Peterborough is agile and flexible enough to meet people’s changing needs, both day to day and in the longer-term.
And if we had to stop using gas overnight, what would Dave do? “Well I have said I’d like to retire and open a coffee shop… but I think I’d stay in the energy industry,” he says. “I like that sense of serving people, actually making a change in people’s lives.”
After all Dave, we need the power to put the kettle on. Though with those 6am starts, a coffee might not be a bad idea.
Published January 2017. All facts and figures correct at the time of publishing.