Energy Service
Energy Service
D
rax is the UK’s biggest power
station; a single-plant utility,
with a capacity of 3,960 megawatts that accounts for one in every
14 watts of electricity supplied nationwide. Completed in 1986, it is also the
most recently built coal-fired plant in
the UK, and Drax’s active approach to
reengineering itself has made the
plant very influential, both in the UK
and beyond. So when something happens at Drax, people in the British
power sector pay attention.
One of the plant’s latest successes is
the replacement of its high- and lowpressure steam turbines: a project
carried out in collaboration with
Siemens. Started in 2007, this fiveyear, £100 million project – the country’s largest ever steam turbine modernization – kept operational interruptions to a bare minimum. But the
key benefit of the upgrade has been
improved efficiency. At a ceremony to
mark the project’s completion, Drax
Chief Executive Dorothy Thompson
said, “As the UK’s largest coal-fired
power station, we take our responsibility to cut carbon emissions seriously.” Her colleague, Production
Director Peter Emery, added: “The
completion of this project makes our
turbines among the most efficient in
the world.”
Green Megawatts
Siemens has replaced the steam turbines at the giant Drax
power generation plant in the United Kingdom, in a five-year
project that has raised the bar for technical efficiency, with
minimal outage time. At the same time, the project also
showed just how closely two companies can work together.
Text: Daniel Whitaker
The five-year project to upgrade the Drax power plant is the largest steam turbine modernization in British history.
60 Living Energy · No. 8 | July 2013
Photos: Siemens
Environmental and
Efficiency Benefits
The new turbines have enabled Drax
to cut its emissions of carbon dioxide
by one million tonnes per year – the
equivalent to taking 275,000 cars off
the road. They have increased the
overall efficiency of the power station
(energy output divided by net calorific value of energy input) to almost
40 percent, which is an industry-leading performance in UK coal-fired
electricity generation. On an international scale, the UK is already among
the more efficient countries when it
comes to fossil-fired power production.
Both Drax’s management and the
Siemens staff involved in the project
attribute its success to the way in
which the two companies were able to
work together, in an unusually close u
Drax – the Facts
The plant
Turbine hall: 400
meters long, with six steam turbine sets – each
of which can generate 660 megawatts – and three gas turbines
Each turbine set contains one high-pressure, three intermediate-pressure,
and three low-pressure turbines
Chimney: 259
meters high – the tallest in the UK; when built, the
tallest in the world
Coal storage: 30
bunkers, each of which can hold 1,000 tonnes
Biomass storage: four giant domes
The fuel
In 2012, approximately 9.6
million tonnes of coal were burnt
Since 2003: biomass, especially wood pellets, sunflower pellets, olive,
peanut shell husk, and rape meal, most of which are imported;
petroleum coke from oil refinery coker units
The output
At 28
terawatt-hours of electricity, the second-highest plant
production in Europe after Bełchatów Power Station in Poland
Drax is situated near a village of the same name, a few
kilometers south of York. It was built there to take advantage of the Selby coalfield, which closed in 2004.
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Energy Service
Achievements of Service Enhancement
Drax, the UK’s largest power station, contracted Siemens to upgrade its high- and low-pressure steam turbines over five years.
This was completed on time, with minimal outage times for each
turbine unit and without any health and safety incidents.
• Drax’s low- and high-pressure turbines were upgraded on time,
to budget, and without safety incident
• The power station’s efficiency level has increased to almost
40 percent, a major financial saving
• Reduction in annual CO2 production of one million tonnes
collaboration. As Darren Davidson,
Head of Projects at Siemens Energy
Service Fossil UK, explained, “The
large size of the project meant that
we had to do something different
from what we normally implement.
With a tight timescale and a grand
scale of implementation of all these
new components, there was the need
for a close relationship.”
His counterpart, Steve Austin, Drax’s
Turbine and Feed Mechanical Engineering Section Head, agrees that the
intercompany relationship was of
central importance: “It was the right
mind-set – the people made this project. Siemens allowed eight to ten Drax
people to work within Siemens’ project team.” And the results speak for
themselves: “All the units were delivered right first time,” Steve Austin
recalls, “with zero harm outages, and
every unit producing more megawatts
than planned.” There was not a single
health and safety incident, and the
downtime for each turbine unit during its replacement was reduced to an
impressive 55 days.
Both companies took a gamble in delegating significant decision-making
power to the joint project team. Initially, there had been doubts that two
sets of employees, from different corporate cultures, could meld together
effectively. Darren Davidson recalls:
“People said it wouldn’t work. But we
pushed and tested it, and it did.”
Anglo-German Cooperation
Photos: Siemens
• Drax is currently converting three of its six generating units
to burn sustainable biomass in place of coal
Energy Service
Components were first engineered in
Newcastle (in England’s northeast),
where the power station’s original
turbines had been made and where
the Drax staff could regularly visit
and provide input to the process.
Then they were procured and manufactured at Siemens Mülheim an der
Ruhr (in Germany’s Ruhr region).
The Drax staff continued their close
involvement, visiting all the major
international materials vendors who
contributed to the process. The results were six new turbines consisting of 28 separate turbine rotors including spare rotors, which together
weighed over 2,800 tonnes, as well as
more than 80,000 individual turbine
blades, which, lying end to end,
would stretch for 42 kilometers.
One of the ways in which Drax has
been making headlines has been its
commitment to transforming from a
mainly coal-fired to a predominantly
biomass-fired power generator. By
replacing three of its six generating
units, the plant aims to become the
UK’s largest biomass-fired power
generator. However, with biomass,
there are several challenging differences from coal: Biomass cannot be
left outside in the wet British climate;
greater volumes are required than of
coal; and biomass produces dust that
must be carefully controlled.
The main advantages of biomass are
that it is renewable and low carbon.
Importantly, replacing coal results in
significant savings of CO2.
The first of the three units was converted at the beginning of April.
The 114-meter-high cooling towers are part of the cooling water system.
An Enduring Partnership
Siemens (and Drax) can be pleased
that a demanding standard was met
in the technical delivery of the turbine upgrade project. The more qualitative lessons regarding planning
processes and intercompany working
are also lessons that can be applied
more widely.
Proof of client satisfaction with the
project was visible in March of this
year, when Drax announced that it
had awarded a new contract to
Siemens, to replace three of its intermediate-pressure steam turbines –
in each of the units converted to biomass. The first module is scheduled
for installation in 2014, with project
completion anticipated for 2015. p
Daniel Whitaker is a freelance technology and
business writer who divides his time between
the UK and Spain. His work has appeared in the
Financial Times, The Times and the Economist,
among others.
The Power of Partnership
View our film on the joint modernization
project of Drax and Siemens online:
siemens.com/energy-channel/uk-drax
Living Energy at
At 28 terawatt-hours of electricity, Drax is the single-largest source of electricity in the UK.
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