Tag: Drax Power Station

The problem solver

Adam Nicholson

“One of the things I like about my job is working through the challenges we get on a daily basis and finding a solution,” explains Adam Nicholson, Process Performance Section Head at Drax Power Station.

That eagerness to find solutions makes him the ideal candidate for his current job: managing day-to-day improvements at Drax. “I’m responsible for the team which ensures the plant operates at optimum efficiency,” he says. His team make sure the turbines, boiler, emissions, combustion, and mills are not just working, but running as smoothly as possible. It’s a job that brings up constant challenges.

“It’s ultimately what I became an engineer for,” he says, “to follow that problem-solving thirst through.”

Earlier in his career, Nicholson was involved in one of the plant’s biggest problem-solving missions: converting it from running exclusively on coal to also run on compressed wood pellets. It was a unique test – one that required starting from scratch. There wasn’t a bank of existing knowledge that Nicholson and his fellow engineers could call upon.

“We did a lot of testing to learn more about the fuel,” he explains. “We had to understand how to get it to the boiler, how to process it before we put it in, how to convert the mills, and then how exactly the combustion would work.”

Some of that learning involved experimenting with unorthodox solutions to complex problems.


The dog tunnel

“One of the big problems with biomass is you can’t expose it to as high a temperature as you can coal,” Nicholson explains. This presented a challenge when it came to pulverising it.

Before fuel at the power station can be combusted, a set of mills pulverises it into a fine powder using a ring of rotating, heavy-duty balls. This fuel powder is then dried inside the mill with a mix of hot air drawn from the boiler house and cool air. But a fundamental difference between coal and biomass meant this process had to change.

“With coal the air can enter the mills at about 300 degrees. With biomass, if you get much above about 180 degrees, the biomass will set on fire,” says Nicholson. As part of the R&D phase he needed to work out a way to cool the mills down on a temporary basis. “We all took a big gulp and thought, ‘how are we going to do this?’”

Part of the problem was the existing ducts weren’t big enough to deliver enough cool air to the mills to lower their temperature to a safe range. Nicholson improvised a solution. “It was known as the dog tunnel,” he says.

If he could get a temporary, larger air supply to the mills it could provide more cool air and lower the overall temperature, allowing the testing to be conducted. So he found a company that could supply industrial flexible ducting, which he connected to a larger cold air duct and then fed through to a mill to deliver more cool air. As its informal name suggests, the result didn’t look like much, but it worked.

“It didn’t look like a finished solution, but the theory behind it was sound. For occasions like this we had to think, ‘let’s just do it, prove it, and then we can work on a permanent solution.’”

“That’s ultimately what I became an engineer for. To follow that problem-solving thirst through.”

The next challenge

Now the power station is successfully producing more than half of its electricity from biomass, Nicholson’s day-to-day responsibilities lie in ensuring safe operations and driving process efficiencies. To do this he keeps tabs on the combustion process – for example, by using thermal imaging cameras to monitor the inside of the furnace – and tweaks it to get as much energy as possible from the biomass fuel.

But at a site as large and complex as Drax there will always be new engineering challenges that require inventive thinking.

“Often you don’t know how you’re going to do something until you do a bit more work and try and understand the problem,” Nicholson says. “We’re nowhere near the end of our learning curve.”

Taming the electric beast

Gareth Newton

“It’s like a living animal, is Drax. It will break, it will fail, it will need maintenance,” says Gareth Newton. As a mechanical engineer in one of the power station’s maintenance teams, he’s a man with a closer eye on that animal than most.

And when something does need fixing or improving, it’s his job to make sure it happens. It’s a task that keeps him busy.

On top of the teams

“I’ve got a team servicing the filter fans. I’ve got a team doing a filter change on a biomass unit. Then I’ve got another company doing a pipework replacement on a discharge line for me. Somebody else is doing a service on the belt cleaners,” Newton says, listing half a typical day’s responsibilities. On any given day, he oversees a number of different teams that carry out a variety of maintenance tasks, and more often than not that list is a long one.

He’s a part of the Materials Handling team who deal with all the material arriving and leaving the power station. This includes the biomass and coal fuel coming in, and the ash, gypsum and other byproducts from the generation process going out.

It means he has a hand in the maintenance of almost all parts of the plant, from the compressed wood pellet storage domes to the boiler. With such a broad perspective of such a complex plant, he knows it’s not always the things you expect to fail that need fixing.


Monitoring the machine

“It’s a machine – it’s being used. It’s not a showpiece or something in a museum. It’s real and every now and then it will throw a gear out and stop,” he says. Those failures don’t always happen to a schedule, so when something does go wrong it can be unexpected.

“You might have a £50,000 gearbox sat in the stores ready and waiting to replace a faulty one, but it will be the £10 probe on a conveyer belt you never thought would break that fails and holds the whole system up,” he says. When something like that happens, he adds, it’s not always about having the exact tool that can fix it right there and then, it’s about thinking out of the box.

“The biggest part of this job, and I think it’s one of the biggest parts of heavy industry engineering, is not fixing or modifying things with what you’ve got,” he says. “It’s about using what you haven’t got to try and engineer your way out.”

He continues: “If you haven’t got a tool or part that you need, can you make something new, can you find a way to make it work? Or, do you even need it?”

“It’s like a living animal, is Drax. It will break, it will fail, it will need maintenance.”

Keeping your hands dirty

Newton grew up around engineering. His father ran a salvage yard and precious metals business and would bring back broken bits of machinery for the kids to fix as toys. “I’ve always had dirty hands,” he says.

It’s something that’s stuck with him. Today, even though he now spends a large proportion of his time monitoring jobs at a computer or moving between teams, it’s the practical side of the job that keeps him interested. “The best part of the job is working with your hands.”

And even though the demands of the living animal that is Drax can sometimes keep him on site longer than his working hours, it’s a beast he’s happy to look after.

“It’s a job you either love or hate. If you didn’t enjoy the engineering side you probably wouldn’t like it because there’s a lot of ingenuity and thinking on your feet needed,” he says. “But there are a lot of jobs out there that I wouldn’t want.”

The toolmaster

Andrew Storr

Before Drax Power Station was a part of Andrew Storr’s career, it was a part of his local environment.

“When I was at school in Selby they were building the second half of the station,” he says. “We could see them building the cooling towers out of the classroom windows.”

But it wasn’t until a careers advisor brought an old cine film of the power station into class that he considered working there. “Part of the film was them stripping the turbine and I watched it and thought, ‘I want to do that,’” he says.

Today, Storr does more than strip the turbines, he’s part of the engineering team that oversees them – a job that needs to be taken seriously.

“If the turbine’s off, forget the rest of it: we’re not generating electricity ,” he says. “We’ve got to make sure the turbine and the generator are absolutely as bulletproof as possible because we’ve only got one per unit.”

Considering the conditions each one comes under, this is no easy task. “The turbine shaft weighs 300 tonnes and spins at 3,000 rpm. The high pressure turbine is 165 bar, and temperature-wise, the steam running through it making it spin is 565 degrees centigrade.”

Bulletproof is an understatement. When it comes to carrying out maintenance on a turbine, it’s more than likely you’ll have to visit Storr’s workshop.


Fixing the governor

The workshop hasn’t always been there. It all started fifteen years ago when a piece of equipment broke. It was a turbine governor relay, a  precision hydraulic actuator that keeps the turbine spinning at the right speed. Drax needed a new one.

“They’ve got to be 100% reliable,” Storr explains. “If they lose control of the turbine, it can either come to a grinding halt or speed up too much and self-destruct.”

The team went in search of a replacement, contacting a manufacturer who came back with a sky-high quote. But Storr’s boss at the time had another idea.

He asked whether Storr could reverse engineer a full set of governor relays. “I made the fatal mistake of saying, ‘Yeah!’ So I set off with a few photographs and a handful of sketches,” Storr explains.

What followed were sleepless nights and a lot of grey hair, but in the end he managed to reproduce a full set that cost nearly half of the original quote. Better than that, they worked perfectly.

“Today, they’re on Unit 5, doing the business.”

Building the workshop

Manufacturing the governor relays was a turning point. Storr and the team saw there could be further savings and benefits if they did more manufacturing or refurbishment in-house. They had the staff capable of doing it, they just needed the facilities.

Although there was some initial scepticism from some in the company, Drax armed Storr with a small budget and he set out on building the workshop. That was 15 years ago. Back then, the workshop was designed to only refurbish equipment, but it has since grown. Now they can manufacture, too.

Today, when Drax buys in equipment which is either very expensive or lacking in quality, Storr’s team can modify it, make it fit better, last longer, or improve its efficiency without sending it away from the plant and incurring extra costs.

“We’re reaping the rewards. We’re leagues in front of everyone else in the UK because we’ve got our own manufacturing and machining facility,” Storr says. “We can do all this work on site. We’re not relying on other people.”

The workshop has given Drax an edge when it comes to its engineering ability, but Storr remains modest about the achievement.

“The thing is,” he says, “I’ve got a good boss and he will support you. But I do see it as a bit of a feather in my cap.”

The life of an electrical engineer

Gary Preece

A station like Drax doesn’t run itself. Its six turbines generate nearly 4,000MW of power when operating at full load. Unsurprisingly, for a site that produces 7% of Britain’s electricity needs, the role of an electrical engineer is an important one – both when managing how power is connected to the high-voltage electricity transmission grid, and how the giant electrical machines generating the energy work.

“It doesn’t get much bigger than Drax. You need to be at the top of your game, every day,” says Lead Engineer Gary Preece.

A man at the top of his game is a fair way to describe Preece. He has been an electrical engineer almost his entire life. Beginning as an apprentice working at the Liverpool dockyards at age 16, Preece has worked a range of increasingly demanding projects and roles, including engineering consultancy and work for the Royal Navy on their Type 26 Global Combat Ship, where he was in charge of designing the on-board power infrastructure.

He became a member of the Drax team five years ago.

Life on the job

“On a station the size of Drax, you don’t have a typical day. There are just too many systems that can change status, that can fail, or that require immediate attention to remain operational. It’s never-ending,” Preece says.

Working as an electrical engineer in a plant the size of Drax doesn’t just mean getting called down to help out when a fuse blows. His responsibilities as lead engineer encompass a broad range of functions.

“There’s lots to do. There’s a lot of hands-on work, but there’s also a lot of study work.” Tasks can include scoping out, planning and budgeting new projects, working with contractors and suppliers, fault analysis and power level studies.

This last role is what Preece has come to like most about the job – working with sophisticated computer simulations to model output and crisis scenarios, all so Drax can operate at its optimal level with National Grid.

“I really enjoy a lot of the theoretical work,” he says. “We can do so much with this software.”

Of course, there are times when he does have to fix things. And in a power plant, mistakes can have major consequences. “The energy levels in a power plant are so high that when something fails, it usually fails spectacularly.”

This means Preece needs to be on call all day and all night. If there’s a technology failure, he needs to be on the site, finding out what went wrong and directing recovery efforts. “There’s no hiding place. If something goes wrong, you have to fix it.”

Transforming Drax’s electric infrastructure

Sometimes individual projects can occupy all aspects of Preece: engineer, thinker and planner.

One of the most challenging was when Drax wanted to import a largely unused industrial generator transformer unit from Kent to the station in Yorkshire.

The transformer was split into three 200-tonne components. Before transit, Preece and his team conducted extensive checks on the components and oil (transformers contain oil to insulate the coil), to evaluate the state of the machinery. And these steps had to be repeated after every stage of the journey, to ensure no damage had been sustained.

After checks were completed, the units needed to be transported via the M25 motorway to ports in the south of England, from which they would travel by ship on the North Sea, ready to be unloaded and transported to Drax for installation.

However, the team hit complications, this time with the Highways Agency. “The structures were so heavy, that we had to take a ferry from a different port because authorities were worried the bridges we were planning on using to get there wouldn’t take the weight of the units. We had to do a turnaround in the middle of the motorway!”

Getting the extra transformers installed gave the plant some important breathing room in the unlikely event of a failure. “Some power stations don’t have spares. If there was a failure, they could be out of commission for months,” says Preece.

For a power station as large as Drax, that would be disastrous. But even with the extra transformers on site, the number of ways the electrical infrastructure at a power plant can go wrong is huge. That’s why experienced engineers like Preece are as indispensable as the machinery itself.

“Drax is one of the best opportunities you’re going to get for artistic licence. It doesn’t get much bigger.”

These three inches of copper can power a city

A series of unassuming cables extend out of the turbine hall at Drax Power Station. They’re easily missed, but these few inches of copper play an instrumental role in powering your home. Surging through each one is enough electricity to power a city.

But the process of getting electricity from power station to plug isn’t as simple as connecting one wire to a live turbine and another to your iPhone charger. We need an entire network of power stations, cables and transformers.

Linking the network

When the country first became electrified it did so in stages. Each region of the UK was powered by its own self-contained power supply. That changed in 1926 when the UK set up the Central Electricity Board and began what was at the time the biggest construction project Britain had ever seen: the national grid

The project took 100,000 men and five years to complete and when it was finished it connected 122 of the country’s most efficient power stations via 4,000 miles of overhead cabling. It had a sizeable effect. In 1920 there were roughly 750,000 electricity consumers; by 1938 that had risen to 9 million.

The grid has changed in the 80 years that’s passed, but it remains the network that transfers power across the country to where it’s needed, whenever it’s needed.

“The strange thing about electricity is that you could live 10 miles from a power station and you can’t be sure the electricity you’re using is coming from that station,” says Callan Masters, an engineer with National Grid whose job it is to maintain and upgrade the network. “The whole system works together – the whole system has a demand and the whole system has to deliver it.”

And to do this, the network has to be able to deliver electricity quickly and efficiently. Masters explains: “It acts like a motorway for power.”

High Voltage Tower on Sunset, Electric Pylon on field

Riding the motorway for power

The process of transporting electricity involves a series of stages, the first of which is ‘stepping up’ the voltage.

When electricity is transported via cables or wires it loses some of its energy as heat. Think of a lightbulb – as it illuminates it heats up because it’s losing energy. The lower the current of that electricity, however, the less energy is lost. So to reduce these losses when transporting power, National Grid transmits electricity at low currents, which it can do by increasing its voltage.

At the power station electricity is generated at 23,500 volts and is then ‘stepped up’ to 400,000 volts by a transformer. The first of these is located on a substation on site at the power station.

Once stepped up, the electricity is transported through high transmission cables – before being ‘stepped down’ via a transformer on the other end. This stepped down electricity is passed onto a regional distribution system, such as the overhead cables you might find on top of wooden poles before being stepped down a final time. “That’s the role of a little transformer at the end of your street,” Masters explains. Finally, the electricity is transported via a final cable into your home – this time at 230 volts.

All this needs to happen incredibly quickly. As thousands of kettles are switched on to herald the end of EastEnders, the demand of electricity surges. Delivering that electricity at the touch of a button relies on a complex network, but it starts with those inconspicuous few inches of copper at the power station.

Capacity Market Contracts

Drax Turbine Hall
RNS Number : 4484R
Drax Group PLC

Drax confirms that it has provisionally secured contracts to provide 1,203MW of derated capacity, from existing units, in the 2016 T-4 capacity market auction. The contracts are for the delivery period October 2020 to September 2021, at a price of £22.5/kW(1) and are worth £27 million.

Two Open Cycle Gas Turbine (OCGT) development projects participated in the auction but exited above the clearing price. It is expected that these projects will now go on to participate in the 2017 T-4 auction.

The purchase of these projects, along with two others, was announced by Drax on 6 December(2). The initial purchase price for all four projects was £18.5 million, with the total consideration payable dependent on the clearing price in future capacity market auctions(3).


Drax Investor Relations: Mark Strafford

+44 (0) 1757 612 491


Drax External Communications: Paul Hodgson

+44 (0) 1757 612 026

Website: www.drax.com/uk


(1)   2015 real.

(2)   On Tuesday 6 December Drax announced that it had entered into an agreement with Watt Power Limited, a developer of OCGT assets, to acquire four 299MW OCGT development projects. OCGTs are gas-fired power plants that can be used by Drax to provide flexible support to the electricity system to make up any shortfall in generation.

Two of these projects are in an advanced stage of development and participated in the 2016 T-4 capacity market auction. The other two projects require further development in anticipation of their targeted participation in the 2019 T-4 capacity market auction.

The details of the OCGT projects, each with capacity of 299MW, are as follows:

a.     Progress Power Limited is a company holding a proposed development on land located at Eye Airfield in mid-Suffolk. The site has a Development Consent Order (DCO)

b.     Hirwaun Power is a company holding a proposed development on land located at Hirwaun Industrial Estate, Aberdare in the County of Swansea. The site has a Development Consent Order (DCO)

c.     Millbrook Power is a company holding a proposed development on land located at Rookery South Pit near Marston Moreteyne in Bedfordshire

d.     Abergelli Power is a company holding a proposed development on land located at Abergelli Farm, in the County of Swansea

(3)   The range of consideration payable for the four assets is £18.5 million to £90.5 million, dependent on the capacity market auction clearing price, with the top of this range being associated with a price of £75/kW (the current 2016 auction price cap).



If you’re afraid of heights, don’t do this job

Reparing the colling tower at Drax Power Station

Be they for nuclear, coal, or biomass power, cooling towers and their colossal, tapering silhouettes are the most iconic element of the architecture of energy. Drax has 12 of them.

But a structure of that size poses a considerable maintenance challenge. For the first time since Drax’s six towers were constructed between 1967 and 1974, one of them was in need of repair.

Ladder up a Drax cooling tower

What could possibly go wrong?

No matter how well you build something, things can go wrong after more than five decades of continuous operation. Each tower is made from concrete that varies in thickness from seven inches in the middle to around 15 inches at the top and bottom. Over time, even a structure this solid can begin to weaken.

Cooling towers are reinforced with steel bars embedded within their concrete which can rust and expand, causing the concrete around it to crack – a process called spalling. Water vapour, which passes through the towers on an almost constant basis, can also migrate into poorly compacted concrete inside the tower and cause further cracks.

Before the Drax team could set about repairing the towers, they needed to know where these cracks were. Inspecting a structure that tall needed an innovative solution. It needed drones.

Surveying the damage

Drones were used to make a comprehensive, photographic record of the towers that could be inspected for signs of damage. The drones also helped produce a 3D model of the structure to visualise the tower’s defects. It was the first-of-a-kind for the company.

The drone survey found that on tower 3B there were a number of cracked concrete patches on the towers that needed repairing and maintenance was scheduled to coincide with Drax’s 2016 outages – periods during the summer months when electricity demand is lower and parts of the power station undergo routine repair work.

The next challenge was how to carry out these repairs on a structure taller than the Statue of Liberty.

A 3D model of a Drax cooling tower

To inspect the cooling tower, Drax created a 3D model with the help of CyberHawk.

Engineering at an altitude

Drax tower 3B is nearly 115 metres tall, enough to fit in the Statue of Liberty or St Paul’s Cathedral with room to spare.

How do you go about repairing a structure like this? The answer: Steeplejacks. Steeplejacks were called so because, originally, they were the people used for scaling the side of church steeples to make repairs. But a cooling tower presents a distinctly different structure that can’t necessarily be climbed up from the bottom. To scale it and make the repairs, a different approach was needed.

Drax reached out to specialist steeplejack contractors Zenith Structural Access, who build devices that allow the scaling of industrial-scale structures.

Zenith’s solution was to fix a metal frame to the top of the tower, which then lowers a walkway suspended by strong metal cables down its side. From a perch suspended from the top of tower 3B, workmen were deployed to make the repairs – more than 100 metres above ground.

Suspended in their cradles, the teams sealed the surface of each crack and then injected resin to fix the cracks in the concrete shell. Where the concrete had spalled, new specialist repair mortars were applied.

Repairs on Drax Tower 3B

Regular repairs

With the identified defects on the tower fully repaired, attention can now move on to others on site. Routine inspections using drones and binoculars have been planned to take place every three years. These will monitor the condition of all the towers and allow for future maintenance to be planned in advance.

Two more towers are already scheduled for repair in 2017’s outages. Once again, it’ll be case for engineering work at elevation.

North Yorkshire tops chart for renewable energy

A new survey from the Green Alliance and Regen SW shows that Selby in North Yorkshire produces the most renewable energy of any area in England and Wales. As you can see, Drax’s home tops the chart by a large margin.

That’s because between three and four per cent of the UK’s electricity is generated from sustainable biomass here at Drax power station.

We’ve already converted half the station to use compressed wood pellets. That half of Drax has reduced its carbon emissions by more than 80 per cent as a result.

But there’s so much more Drax could do to help the UK get more coal off the grid. And if the Green Alliance’s next data visualization pitted renewables against fossil fuels, a renewable-only Drax as our country’s biggest power station would give low carbon technologies an even bigger share than would be the case today.

Drax can not only generate more renewable power ourselves, but also help solar and wind power to cope with demand as some of the older coal, gas and nuclear plant retire over the coming years.

Moving towards a balanced mix of renewables including further biomass upgrades at Drax could save bill payers billions of pounds found research carried out by NERA and Imperial College London.

This was commissioned by Drax to establish the ‘true’ cost of the main forms of renewable energy – wind, solar and biomass.

The UK is already far below the European average when it comes to using wood for energy.

If the government made the right decision and levelled the playing field for biomass in the UK, Drax could help our country climb the table, meet our national climate change targets more quickly and contribute to saving bill payers billions of pounds. Upgrading from coal to wood pellets is also ensuring Drax Group – which employs more than 1,400 people – has a real future at the heart of the Northern Powerhouse.

However it’s not just for government to change the status quo – businesses have a role to play too. Many UK businesses have made firm commitments to limit and reduce their impact on the environment. For all, their use of energy is a critical area to consider and address. Some of the biggest electricity users such as Thames Water and Manchester Airport Group are increasingly demanding renewable electricity. Drax Group’s Haven Power is proud to offer the only 100% guaranteed renewable electricity product in the market to businesses big and small.

Perhaps that’s what the Green Alliance’s next index could investigate – which businesses have taken practical steps towards a renewable future.

How to plug the electricity gap

By 2025, the UK will face a 40-55 per cent gap between electricity supply and demand, according to a report from the Institute of Mechanical Engineers. The government has disputed IMechE’s projection but its own forecasting suggests that UK electricity demand will be 19% higher in 2035 vs. 2015.

The alleged 2025 gap will be caused by the closure of coal-fired power stations to meet targets for carbon reduction. According to the IMechE, current plans to plug the gap by building new gas-fired capacity are unrealistic. (It would require a staggering 30 new power stations to be planned and built from scratch within the next 10 years.)

At Drax, we have already developed a solution. We can do it quickly, cheaply and safely. In fact, it would drastically reduce the time and money involved in building all of those 30 new gas power stations from scratch.

We’ve already adapted three of our coal-fired generating units to use high-density pellets made from compressed low-grade wood. And we’re using world-beating technology developed by our own engineers here in the UK to do it.

In all, around four or five per cent of the UK’s entire electricity needs every single day of the year are already being met thanks to our unique biomass technology at Drax. It’s an approach that could be adopted elsewhere in the country, providing a huge contribution to plugging the electricity gap.

Our high-density compressed wood pellets are the only non-fossil fuel that can bring about these changes in the time we have left.

Given the right support, within two or three years, we could convert the remaining three units at Drax power station to run on biomass wood pellets.

With all six units converted, plus Lynemouth power station – which already has that future secured – and one or two other, smaller biomass power stations, around 10 per cent of the UK’s electricity could be generated using this technology well before 2025 – long before new gas-fired capacity could come on stream.

The costs involved would be dramatically lower too. We invested around £650 million to convert three generating units, develop a supply chain and build new storage at Drax. It is estimated that the equivalent in new combined cycle gas turbine power stations would cost more as it would be new rather than repurposed infrastructure.

Energy hierarchy

The IMechE has developed an energy hierarchy, listing five sustainability-related priorities against which to judge any future energy strategy. The two that focus on energy generation are a perfect fit in terms of coal-to-biomass conversions at Drax and Lynemouth.

“Priority 3 – utilisation of renewable, sustainable resources”

High density compressed wood pellets are made from low-grade wood sourced according to the highest levels of forestry conservation.

“Priority 5 – utilisation of conventional resources as we do now”

Using world-leading engineering skills and avoiding the need to build brand new power stations, our coal units can be converted without the need for new National Grid connections.

Many of our European neighbours such as Sweden and Germany already use a far higher proportion of biomass to meet their energy needs. Catching up with the European average is the simplest, quickest and most affordable way to avoid a shortfall between supply and demand predicted by 2015.