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Power and the rise of electric cars

Power supply for electric car charging. Electric car charging station. Close up of the power supply plugged into an electric car being charged.

All great technological innovations need infrastructure to match. The world didn’t change from candles to lightbulbs overnight – power stations had to be built, electricity cables rolled out, and buildings fitted with wiring. The same is true of electric vehicles (EV).

Think of the number of petrol stations lining the UK roads. If EVs continue their rise in popularity, the country will need electric car-charging facilities to augment and then replace these petrol stations.

This could mean big extensions of electricity grid infrastructure, both in the building of new power generation capacity to meet demand, and in the extension of the networks themselves.

In short, it could mean a significant change in how electricity is used and supplied.

The need for better electricity infrastructure

In 2013, only 3,500 of newly registered cars in the UK were plug-in electric or hybrid EVs. In 2016, that number jumped to 63,000. Their use is rising rapidly, but the lack of infrastructure has kept a cap on the number of EVs on UK roads. That is starting to change.

As of 2019, all new and refurbished houses in the EU will have to be fitted with an electric car charging point, according to a draft directive announced by Brussels. The UK will probably no longer be an EU member by the time the directive comes into effect, but nevertheless, the UK government is pursuing its own ways to account for the rise of EVs. It has pledged more than £600 million between 2015 and 2020 to support ultra-low-emission vehicles – £38 million of this has already been earmarked for public charging points.

There are more innovative responses to EV rise, too. Nissan, in partnership with Italian energy provider Enel, has announced it will install around one hundred ‘car-to-grid’ charging points across the UK. With their innovative V2G technology, cars plugged into these sites will be able to both charge their batteries and feed stored energy back to the National Grid when necessary. So when there is a peak in demand, the Grid could access the cars’ stored energy to help meet it.

The total capacity of the 18,000 Nissan electric vehicles currently operational on UK roads comes to around 180 MW. So even today – before electric vehicles have really taken off – this could give the National Grid an additional supply roughly the size of a small power station.

Peaks in electricity demand, however, tend to occur in the late afternoon or evening as it gets dark and more lighting and heating gets switched on. This also happens to be rush hour, so under this scheme the time of day the cars are most likely to be on the roads is also when it’d be most helpful to have them plugged in. This could lead to financial incentives for people to give up the flexibility of driving their cars only when they need to.

Power supply for electric car charging. Electric car charging station.

More electric cars, more demand for electricity, more pollution?

More EVs on the road makes sound environmental sense – they enable a 40% reduction in CO2 emissions – but ultimately the energy still has to come from somewhere. That means more power stations.

The scale of this new demand shouldn’t be underestimated: if European drivers were to go 80% electric, some studies have suggested it would require 150 GW of additional on-demand capacity – the equivalent of 40 Drax-sized power stations.

But if EVs are to live up to their green potential, that additional power needs to come from innovations in storage (such as in the Nissan example) and from renewable sources like wind, solar and biomass. Fossil fuels would ideally be used only to plug any gaps that intermittency creates – for example by briefly firing up the small gas power stations Drax plans to build in England and Wales.

What does this mean for generators?

Drax, as operator of the UK’s largest biomass power station and with plans for new, rapid response open cycle gas turbines (OCGTs), is well placed to be at the forefront of providing reliable, affordable power in the event of a widespread rollout of electric vehicles. The OCGTs in particular, are designed for use in peak times which, in the future, could be when the nation’s electric vehicles are plugged in overnight – today this is when electricity demand is at its lowest.

A future of more electric cars is a positive one. They’re cleaner, more efficient, and they are well suited to our increasingly urban lives. But now that we have the technology, we need to ensure we can deliver the lower-carbon infrastructure they need.

Some like it hot: how temperature affects electricity prices

misty-british-county-landscape

In 2012, Europe faced an extreme cold wave. Temperatures in France dropped to minus four degrees Celsius, far below its average of five above.

As people huddled indoors, electric heaters were dialled up and lights were switched on. Electricity demand soared. It topped at 102 GW, surpassing the country’s previous peak by more than 20 GW. France had to import power from neighbouring countries.

The low temperatures drove demand so high the country couldn’t manage on its own. It’s something we see across the world – temperature peaks drive how and when we use electricity, increasing demand in the colder Northern European countries as the temperature falls, and acting inversely in hotter Southern countries.

But more than just driving up how much electricity we need, the temperature can affect how much we pay for it, too.

Putting a price on electricity

In the UK electricity is bought and sold by power generators, energy suppliers and the National Grid by the megawatt hour (MWh). One MWh is roughly enough power to boil 400 kettles and although prices fluctuate significantly, on average one MWh costs roughly £50 in the UK. In winter, when UK electricity demand peaks it’s estimated that for every degree the temperature drops below 15 Celsius, demand rises by 820 MW.

Electric Insights, an independent report produced by researchers at Imperial College London and commissioned by Drax via Imperial Consultants, looks at the UK’s publicly available electricity data and clearly shows the trend.

Electricity demand, temperature and prices

As the temperature drops, demand rises.

This raised demand affects the price of electricity in one obvious way: consumers’ bills rise because they’re using more of it. A less obvious impact is its effect on the production and supply cost of electricity from generator to the high voltage electricity transmission grid.

How temperature affects supply

In cold weather power plants work better. Cooling towers are more efficient, power cables are more conductive, and less energy is needed to help keep generating equipment from overheating. This all adds to small cost savings, which in turn can make electricity cheaper.

However, during colder weather the amount of gas used in the UK goes up – largely due to the rise in heating – which raises its price and this has a knock effect on electricity. For every 1p increase in the cost of gas, the cost of generating 1 MWh by a CCGT (combined cycle gas turbine) power station increases by around 70p. As CCGTs generate a large percentage of Britain’s electricity, the overall price of electricity also goes up.

But a bigger cost-determining factor is the increasing variety in today’s energy make up. Renewables like wind and solar are intermittent energy sources. Solar can’t function at night or when it’s overcast; wind turbines don’t rotate when it’s still, so when it is especially cold, dark or without much wind, the Grid needs to bring in additional flexible power generated by sources like biomass, gas and coal. These technologies can either deliver power to the Grid all the time – known as baseload – or just when demand rises, when they can be dialled up quickly.

But in the event of extreme weather, the demand for power can surge and the Grid needs to bring in additional generation capacity. In Britain, there are smaller power stations fuelled by diesel, oil or gas that lie dormant for much of the year but can start up at short notice to provide this boost of generation to meet demand.

Activating and running these plants quickly for short amounts of time can be expensive, and this can subsequently affect electricity price and lead to spikes in the winter.

Pylons in the countryside with the sun behind themThe effect on the bottom line

This leads to the following trend: for every degree Celsius the temperature falls below 10, there is a corresponding rise of £1.10 MWh. It is also possible for increases in temperature to cause increased prices, but this is usually in countries where air conditioners and electrically-powered cooling units are hooked up to their own national or regional electricity grid. For better or worse, this is not a problem that affects the UK, but it’s important to understand that maintaining grid stability will always have its costs, whatever the weather.

 

The new Renewable Energy Directive and what it means for biomass

European union flag against parliament in Brussels, Belgium

***This story was published the day before the announcement by the European Commission. Please scroll to the bottom of this page for the Drax view ***.

When the European Union set out its policy for the promotion of renewable energy in the 2009 Renewable Energy Directive (RED) it set a very ambitious target: by 2020, renewables should make up 20% of the EU’s energy consumption. Each Member State was given a specific goal and made to detail exactly how it would hit this.

The Directive was comprehensive in many ways, but it didn’t include a clear sustainability policy for solid biomass, including compressed wood pellets. As one of the largest sources of renewable energy in Europe, this left a policy gap that many voices – including Drax – have called to be filled.

It’s a wish that will now be granted. A revised RED is set to be published by the EU that will specify clear criteria for all biomass.

“Sustainability has always been absolutely central to our biomass strategy but Drax has always argued that there is a right way to source biomass and a wrong way.”

Dorothy Thompson, Drax Group CEO, July 2014

Importance of sustainable biomass

Biomass is a well-established and essential part of the renewable energy mix. It offers a unique mix of reliability, flexibility and affordability, all while helping to deliver carbon reductions. This makes it particularly important as countries like the UK seek to phase out coal generation and hit the targets set out in the Paris Agreement.

However, in order to secure these carbon benefits biomass needs to be produced sustainably. This means that it comes from responsibly-managed, growing forests, and that the emissions from the supply chain are measured and minimised.

In the UK there are already binding sustainability criteria but this isn’t the case across the EU. Biomass use in the UK is regulated under the EU Timber Regulations and UK’s own Renewable Obligation (RO) biomass sustainability criteria.

The RO is a form of government support designed to incentivise large scale renewable electricity generation in the UK, and to qualify for this, energy companies must adhere to sustainability standards such as properly accounting for their greenhouse gas (GHG) emissions and only sourcing from responsibly managed land and forests.

An EU-wide approach to biomass that follows the UK’s could see the implementation of a risk-based scheme that asks large energy companies to prove how they mitigate against a set of identified risks – like those in the RO criteria. However, it’s important that compliance with these is independently verified – something that could be done by using independent schemes such as the Sustainable Biomass Program (SBP).

The SBP carries out supply-base evaluation of pellet producers to ensure the wood they’re using is qualified as sustainable and they’re meeting the RO criteria. Programmes like the SBP are already being used by most major biomass power generators in the EU and could act as a blueprint for the future.

Two workers stand next to machinery at the Morehouse facility in the USA.

Efficiency where effective

Only a few of the power stations across the EU are suitable for conversion from coal to biomass but those that are, like Drax, can deliver fast, significant carbon savings.

The thermal efficiency of such stations may not be as high as a newly built plant, but they do allow governments to quickly move away from coal. More than that, these plants can continue to provide the critical services – such as voltage control and black start – the grid needs to remain stable and that other renewables can’t.

Drax is one of these stations, and in the first half of 2016 it was able to deliver around 20% of the UK’s renewable power. Thanks to its conversion to biomass, it now does this with over 80% carbon reductions relative to coal.

With the abundance of suitable and sustainably-grown fibre that can be used for biomass electricity generation, there is a strong case for the EU to encourage the coal phase out by encouraging others to undergo conversion from coal to biomass.

But what’s also needed is a clear set of sustainability criteria for biomass. The move to define this is a step in the right direction but the final EU proposal needs to be a practical one.

If the updated RED achieves this, it will mean a bright future for renewable energy in Europe and a clearer path for meeting the continent’s Paris Agreement targets.

*** 30 November, 2016 UPDATE ***

Drax welcomes Renewable Energy Directive proposal

Drax welcomes the publication of the Renewable Energy Directive and bioenergy policy proposal. Drax has been at the forefront of calling for standards based on a risk-assessment to demonstrate the sustainability of biomass used for energy production.

Matt Willey, Public Affairs Director of Drax Power had said that:

“Drax has campaigned for a robust, pragmatic biomass sustainability policy for the whole EU for many years and today is a step in the right direction. It is important that large users of biomass can demonstrate forest regeneration is taking place, that areas of high conservation value are protected, that soil and water quality is maintained and that harvesting does not exceed the long-term production capacity of the forest. We welcome the fact the Commission proposes that voluntary national or international schemes, including those which use a risk based approach, can be used to provide evidence of sustainability.”

“The UK already has the toughest sustainability rules in the world so Drax can be sure our compressed wood pellets are sustainable but it makes sense to have a common policy across the EU.”

Drax Power has made huge efforts to demonstrate the sustainability of its biomass. Sourcing from regions with large surpluses combined with low wood paying capability, Drax is able to track and trace every shipment back to low risk areas, which assures that biodiversity is protected and promotes sustainable forest management.

This train isn’t like any other in the UK

Man standing in front of train

For decades the sight was the same. Day after day, trains pulling open-top wagons filled with coal would arrive at Drax Power Station. Coal was the fuel on which the station ran, but as that changes and the world moves from the dirtiest of fossil fuels to renewables and other lower carbon technologies, so too do the make-up of Drax’s daily deliveries.

Now, more than half of Drax’s power is generated from compressed wood pellets instead of coal. The trains still arrive daily, but in addition to coal carriages, more are pulling state-of-the-art biomass wagons. They’re not only the first of a kind, they’re bigger than any others on UK railways.

Moving a modern fuel

Coal and biomass are fundamentally different. Whereas coal is a durable fuel that can be left open to the elements without concern, if compressed wood pellets are left in the rain they become unusable.

In short, traditional hoppers, the large open-top train wagons used to transport coal, aren’t big enough, nor do they provide enough protection, for transporting biomass.

To deliver roughly 20,000 tonnes of wood pellets to the power station every day it would need an entirely new railway wagon. For this Drax turned to Lloyd’s Register Rail (now Ricardo Rail) and WH Davis.

DRATECH19_Train_crane_In_line_dp7ney

Putting a lid on it

One of the first things to solve was the open top. The team designed a pneumatically operated roof for each wagon that could open and close on demand – providing easy access for loading, but suitable protection for the pellets when in transit.

A similar system on each wagon’s base was introduced to make unloading just as simple. A typical hopper design includes a wide roof that narrows into a shoot at its base for releasing fuel. The Drax wagons are different.

When they arrive at the power station, automated flaps on their underside open in stages as they pass through the biomass unloading area. This releases pellets into a sorter that delivers them into storage, ready to be used for generation. With this system in place, each train can unload in under 40 minutes.

The big problem: space

A more significant hurdle to overcome was the question of space. The obvious answer was to make the wagons bigger, but UK railways have some of the most restrictive dimensions in the world thanks to its bridges and tunnels – some of which were constructed in Victorian times.

So to get a similar efficiency out of the compressed wood pellet loads as previously obtained with coal, the wagons needed to be bigger – not in physical size, but in volume.

The team looked to the normally unused space at the ends of traditional wagons to house the braking and control equipment cubicle, while the pipework was designed to run inside the wagon’s siding, creating more inside storage space.

The result is a wagon with 116m3 capacity, almost a 30% increase in volume compared to the coal wagons. They are not only the first ever bespoke biomass wagons, they’re also the largest on UK railways.

DRATECH19_Train_Journey_In_Line_dgx81z

Bigger wagons, better economy

The impact of these wagons is felt beyond just the railway lines. WH Davis is the UK’s last independent freight wagon manufacturer and relationships like this are not only good for Drax, but positively impact the wider UK economy.

A joint study by Oxford Economics for Drax calculated that in the East Midlands, where WH Davis is headquartered, Drax supports 1,100 jobs through its supply chain and the resulting economic activity. In total, the report found Drax had added £60.3 million to the local economy through indirect and induced means. Nationwide, in 2015 that impact extended to a total of £1.24 billion in contribution to the UK GDP and more than 14,000 jobs.

There’s potential for this impact to be even greater. Roughly 14 trains arrive every day at the power station from ports in Liverpool, Tyne, Immingham and Hull, delivering up to 20,000 tonnes every day to fuel the three of Drax’s six generating units that run on wood pellets. But if all six are upgraded it will mean more biomass, more deliveries and more trains.

The railways have always been a part of the power station, and in the foreseeable future it’s likely they always will be.

Building a 21st century port

In its long history, the Port of Liverpool has dealt with a number of industries. It’s a port characterised by its ability to adapt to the needs of the time. In 1715 it emerged as one of the world’s first ever wet docks. In the 18th century it was used as a hub for the slave trade.

When slavery was abolished in the early 19th century, Liverpool switched to bringing in the goods of the thriving Empire, such as cotton. When goods like cotton dried up, it switched to the fuel of the Industrial Revolution: coal.

Now as the world (and the UK government) moves away from fuels like coal and towards lower-carbon and renewable resources, the Port of Liverpool needed to adapt once again.

Gary Hodgson, Chief Operating Officer at Peel Ports, explains: “About three years ago everyone was asking, ‘What happens after coal?’”

Biomass silos at the Port of Liverpool

What happens after coal?

Peel Ports is one of the biggest operators of Liverpool’s shipping infrastructure, including Liverpool Port. Seeing that the future of coal was finite, it recognised there was a need for a port that could bring in alternative, renewable fuels.

At the same time Drax was looking for a logistics partner to facilitate the importing of compressed wood pellets. Since 2009 Drax Power Station had begun a process of upgrading its coal-fired boilers to run on sustainable biomass, sourced from huge, well-established working forests. More than this, it had plans to set up its own pellet manufacturing plants in the US South and needed to import large quantities of wood pellets.

The relationship with Peel Ports and Liverpool was obvious. This began a £100 million investment that helped transform the region’s port-station transport infrastructure.

“It’s about working in partnerships with companies,” says Hodgson. “Working this way helps develop solutions that really work.”

The central element of the partnership between Drax and Peel Ports was a radical redesigning of the technical infrastructure. Not only do compressed wood pellets have fundamentally different physical properties to other fuels like coal, they are more combustible and need to be handled safely.

For the three-million-tonne-capacity facility that Peel Ports and Drax wanted to build, innovative supply chain solutions had to be developed.

A tool used to transfer compressed biomass pellets

Shifting biomass in bulk

The first challenge was getting the high-density pellets off giant ships. For this, Peel and Drax designed a solution that uses an Archimedean screw – a long tube with a spiral winding up the inside that allows liquids, or materials that can behave like a liquid (like wood pellets), to defy gravity and travel upwards.

At the top of the screw, the pellets are emptied onto a conveyor belt and carried to one of three purpose-built silos tailored to safely storing thousands of tonnes of biomass.

Here the pellets wait until another conveyor belt deposits them onto specially-design biomass trains where they are transported across the peaks of the Pennines to Drax Power Station near Selby in North Yorkshire.

Each step at the port is automated, designed with supreme efficiency in mind by a team of Drax and Peel Port engineers. End-to-end, port to power station, the whole process can take as little as 12 hours.

Drax biomass ship in the Port of Liverpool

A new chapter for the north

In the varied history of the Port of Liverpool the new facility is another chapter, one that is helping transform the logistics infrastructure and the economic growth of the North West.

Now open and operational, the facility directly employs 50 people – around 500 additional contractors have worked on the project during its construction and development. More than that, it’s an investment in the country’s energy future. It secures a fourth port for Drax –  three others are on the east coast – helping with security of supply.

“We made this investment because we recognised this as the future of the energy mix of the country,” Hodgson explain. “We can’t just rely on one form of power – there has to be an energy mix and we see biomass as a key part of that.”

The cleanest year in Britain’s electricity

Cleanest year in Britain's electricity history

Amid the political upheaval that is characterising 2016 you may have missed the quiet victory of the UK’s low-carbon energy sector: for the first time ever, the third quarter (Q3) of 2016 saw more than 50% of the Britain’s power come from low-carbon energy sources. Five years ago, low-carbon sources made up just over a quarter.

This doesn’t necessarily mean that renewable energy sources made up the full 50% – in fact, nuclear made up a considerable chunk – but it hints at the big changes we’re seeing in the way the country is sourcing its power.

For one, it’s a further sign of coal’s diminishing life. During the period July to September 2012 coal supplied 38% of Britain’s electricity – during this year’s Q3 it supplied just 3%. As a result, per-unit carbon emissions from electricity consumption are at their lowest levels ever. The Carbon Price Floor – also known as the carbon tax and designed to assist energy companies like Drax invest in renewable and lower carbon generation – has played a big role in reducing coal’s contribution.

The findings come from Electric Insights, an independent report produced by researchers from Imperial College London and commissioned by Drax, that looks at the UK’s publicly available electricity data and aims to inform the debate on Britain’s electricity system.

Beyond the continued decline of coal, it shows there’s a growing diversity in low-carbon energy sources fuelling the country and that there’s a positive outlook for a cleaner electricity future.

Here we look at those low-carbon sources and how their use has changed over the last five years.

Nuclear produces 26% of Britain's power (Q3, 2016)

Nuclear

At 26% of the total, nuclear made up the largest proportion of low-carbon power generation across Q3 2016.

That was good news for the sector, which went through a turbulent summer after plans for the Hinkley Point C reactor were momentarily threatened following the dissolution of the Department for Energy and Climate Change (DECC) after the Brexit vote.

The eventual decision to continue with Hinkley C, however, means that more baseload nuclear power, in the form of large power stations and also possibly small modular nuclear reactors (SMRs), will be coming on to the system in the coming years. They will in the main replace older nuclear power stations set to be decommissioned.

Wind produces 10% of Britain's power (Q3, 2016)

Wind

Wind power made up 10% of total low-carbon power generation between July and September, and was the largest renewable source of the quarter.

As recently as 2011, electricity generated by wind accounted for just 4% of Britain’s low carbon energy supplies – a 150% increase in just five years. This is in part due to huge offshore projects such as the 630 MW London Array in the Thames Estuary and the 576MW Gwynt y Môr situated off the coast of North Wales, which have contributed to bringing the UK’s installed capacity to around 14 GW

The UK is now the world’s sixth largest producer of wind power behind China, the USA, India, Germany and Spain.

Solar produces 5% of Britain's power (Q3, 2016)

Solar

Following wind power as the second largest renewable contributor to the country’s low-carbon energy needs was solar.

Five years ago solar’s contribution was so negligible it didn’t even chart in the Electric Insights data. Fast forward to 2016 and Britain has a total installed solar capacity of nearly 10 GW. Again, this places the country sixth in the world for capacity behind China, Germany, Japan, the USA and Italy.

Biomass produces 4% of Britain's power (Q3, 2016)

Biomass

Biomass – a unique low-carbon fuel in that it can deliver both baseload and flexible power – made up 4% of the UK’s power needs in Q3 2016. A good proportion of that came from Drax, which has over the last five years been upgrading from coal to run on compressed wood pellets.

Like solar, biomass generation didn’t even chart in 2011, but today. In fact, between July and September biomass, along with solar and wind, supplied 20% of the country’s electricity – a huge proof point for the rise of renewables. Where biomass sits apart from those two sources, however, is that it isn’t dependent on weather and even though the country has less much less biomass generation capacity than the two intermittent technologies, it produces nearly as much energy as them. This makes it an ideal baseload partner for sources that do (i.e. wind and solar) as it can be dialled up and down to meet the energy demand of the country in seconds.

In the future there’s potential to increase this biomass capacity while saving bill payers money. Three of Drax’s six generating units run on biomass, but if all were to be upgraded as they could be in less than three years – Drax plus Lynemouth power station and one or two smaller biomass power stations – could generate roughly 10% of Britain’s electricity using compressed wood pellets by the time unabated coal power stations come off the system before the end of 2025.

Hydro produces 1% of Britain's power (Q3, 2016)

Hydro

Hydropower made up just 1% of Britain’s power generation over the quarter. However, this is still up by 20% since 2011, when hydropower contributed just 0.8%. Total installed hydropower capacity is around 1.65GW.

However, studies have found the country has a potential hydropower capacity of close to double this amount, but as many of these sources are located in mountainous, rural landscape areas of natural importance, it’s doubtful whether hydropower will be deployed up to its full capabilities in the coming years.

Closing an historic year

May the 5th was an historic day in the UK – it was the first time since 1881 Britain burnt no coal to produce its electricity. It wasn’t an isolated incident, either. In the third quarter of 2016 Britain was completely coal free for nearly six days.

It’s a situation that is likely to continue in the future as low carbon energy sources – and in particular renewables – continue to grow in the country’s energy makeup. The outlook is a positive one. 2016 may have been the cleanest year in UK electricity we’ve seen so far, but it won’t be the cleanest year ever.

Explore the data in detail by visiting ElectricInsights.co.uk

Commissioned by Drax, Electric Insights is produced independently by a team of academics from Imperial College London, led by Dr Iain Staffell and facilitated by the College’s consultancy company – Imperial Consultants.

What does an Instrument Craftsperson do?

Instrument Craftperson in action

How do you go about fixing a turbine that, on a normal day, spins 3,000 times every minute? The first port of call is to call in someone like Alice Gill, an Instrument Craftsperson at Drax Power Station. 

What does an Instrument Craftperson do?

What I do is maintain and repair the equipment that links the outside power plant and the control room – equipment that tracks temperature, levels or positioning that then informs our operators in the control room what’s happening on the plant.

Things like an oxygen analyser. It’s a probe that sits in the boiler and monitors the oxygen level so the operator can ensure the correct ratio of fuel to air is going into the boiler to reach optimum combustion.

I might be called on to do calibration checks on that sensor to ensure that it’s working properly. Or I might be asked to completely remove it and then to repair it.

How did you come to be doing this job?

I’m not the sort of person who likes to sit down at a desk all day – I’m more of a hands on sort of person. My dad was always working and fixing things in the garage at home and I liked being in there with him.

When I was at school I decided I didn’t want to go to university so started applying for apprenticeships and looking into engineering opportunities. Drax was one of those schemes and was the one I most wanted to be selected for – luckily enough I was offered a place.

The apprenticeship was four years and there are loads of training courses and so much to learn, including hands on experience and working in the plant.

I remember first arriving to the power station and not really believing the scale of the place. You think, ‘How am I ever going to find my way around?’, but you soon get used to it and it becomes the norm.

In September I became a full Instrument Craftsperson so now I can really get stuck in.

Alice Gill at Drax Power Station

“I’m not the sort of person who likes to sit down at a desk all day – I’m more of a hands on sort of person.”

What sort of challenges do you face?

Over the summer I’ve been doing a lot of work on the turbines. It’s a big job as they’re one of the most important elements driving the plant and generating the power. During outages the whole thing gets overhauled and given a full health check.

The turbine team needs to get into machinery, which is densely constructed and put together, so it’s my job to go in and carefully remove instrumentation so they can access it. When they’re done, I have to go back in, refit everything and check it’s all working again.

How do you do that?

When you’re removing the instruments it’s a bit more of a ‘just get it off’ approach – you just make sure you get it off safely without damaging it.

Then when we’re refitting it, we’re out there with our multimeters making sure we’re setting different probes at the right voltages and that everything is calibrated correctly.

There’s a screen in our workshop we use to watch the activity of the turbine so we can see the speed of the turbine creeping up as they switch it back on. It’s always a big moment. You know things are going to be alright because you’ve done everything, but there are still some nervous people in the room. The turbines are spinning at 3,000RPM so you really need it all to be working properly.

Is there anything that could wrong on an average day?

One of the biggest things that could go wrong in my area is the potential to trip an entire generating unit. It might be that you over-pressurise something or you accidentally trigger a switch that then sets off a daisy chain of events that ends up in a unit tripping. Tripping is where the unit turns off which basically leads to a total shutdown in electricity generation from one sixth of Drax Power Station.

There’s something called the 660 club – at full load the units are operating at 660 MW so if you trip one you enter into this infamous club. There are a few guys in the 660 club but thankfully I haven’t joined! When operating at full load of 660 MW, our units supply the National Grid with around 645 MW– enough to power an entire city.

What do you do outside of work?

I’ve got a horse called Red – I’ve had him for seven years but I’ve been riding since I was eight. It’s quite different to working with things that do exactly what you tell them. When you get on the horse he just does what he wants – he’s got a mind of his own. It’s a big change!

The turbulent history of coal

Aerial view of coal field

**9 May 2019 update: we have updated this story to mark the new GB record of continuous coal-free hours since 1882**

3490 BC

Households in China work out how to use coal for heat. The coal was bulky to transport, so settlements near forests probably burned it less often than wood.

4th century BC

Greek scientist Theophrastus makes a reference to coal as a fuel in his treatise, ‘On Stones’.

2nd century AD

By the 2nd century AD, the Romans were using coal from most of the main coalfields in Britain. Archaeologists have found flint axes from before the Roman era still embedded in coal. There is evidence that at this time people dug up coal on beaches then followed the seam of coal inland, encouraging them to investigate more sophisticated ways to mine it.

First millennium

Although it’s hard to date them precisely, early mines called ‘bell pits’ – deep holes which tapered outward at the bottom like a bell to provide a bigger surface area for mining – began to appear in the early part of the first millennium. These were lit by large candles burning animal fat and were dangerous: rocks could fall onto the miners and sometimes the pit would collapse entirely.

13th and 14th centuries

Room and pillar mines emerged as larger, more sophisticated versions of bell pits. In these pillars of coal were left standing to support the roof.

16th century

From the 1500s, mining expanded significantly. At this time coal was mostly used for heat by less well-off people. One observer wrote in 1587 that old men told him about “the multitude of chimneys lately erected, whereas in their young days there were not above two or three, if so many, in most uplandish towns of the realm.”

1700 

Great Britain was producing 2.7 million tonnes of coal per year, mostly for use in metal production.

1750

In just half a century Britain ramps up coal production: it was producing 4.7 million tonnes of coal per year.

1763 to 1775

James Watt develops his steam engine, which was used to drain mines. Despite this, flooding remained a problem.

1800

By the turn of the nineteenth century, Great Britain was producing 10 million tonnes of coal, driven by the rising demand of the Industrial Revolution. From about 1800, miners began to leave timber supports in place to hold up the roof of their pits, allowing them to follow coal seams deep into the earth. This was known as longwall mining.

1815

Sir Humphrey Davy invents his safety lamp. It had a wire gauze around it so the flame would not encounter any gas and cause explosions. It became known as “the Miners’ Friend”.

1850 

Great Britain was producing 50 million tonnes of coal.

1882

The world’s first steam driven power station was built on coal at Holborn Viaduct in London. It had a 27 tonne generator, enough to light 1,000 lamps. Later it was expanded to power 3,000. A second coal-fired power station opened later that year in the United States at Pearl Street Station in New York City. It initially served a load of 400 lamps and 82 customers but by 1884 it was powering more than 10,000 lamps.

1900

Great Britain was producing 250 million tonnes of coal.

1947

All Great British coal mines were nationalised (bought by the government) and placed under the control of the National Coal Board.

 1974

After the Selby coalfield was discovered in 1967, Drax Power Station was opened.

coal locomotive on rail tracks

1988

Drax became the first coal-fired power station to install flue-gas desulphurisation technology, which removes 90% of coal’s harmful sulphur dioxide (SO2) emissions.

1994

From the eighties onwards, many coal mines closed and in 1994, British Coal (the successor to the National Coal Board) was privatised.

2004

As a result of UK mine closures and proposed emissions regulations coming into force from 2008, power stations started to increase the amount of coal they imported. Drax Power Station’s supply was initially split between 50% indigenous coal and 50% imported. There was a steadily increasing emphasis on imports for the decade thereafter.

2008

The Large Combustion Plant Directive (LCPD) came into force across the EU, limiting emissions of SO2, NOx and particulates.

2009

The Drax team successfully adapted the boilers of the plant to combust wood pellets. This was proof that a coal-fired power plant could be converted to biomass.

March 2013

The White Rose carbon capture and storage (CCS) project was announced as one of two preferred bidders in the UK’s £1bn CCS Competition. This project looked to build a new 448 MWe coal-fired power station with CCS capabilities on the existing Drax Power Station site in Yorkshire. With CCS technology installed, the power station would be able to capture and safely store carbon emissions underground rather than releasing them into the atmosphere.

1st April 2013

The Carbon Price Floor was launched in the UK. A tax on carbon dioxide (CO2) emissions, it is designed to provide an incentive to invest in low-carbon power generation.

September 2015

Due to reduced renewable subsidies, Drax withdrew from the White Rose CCS project.

18th November 2015

The UK government announced its intention to close all unabated coal-fired power stations by 2025 and restrict their usage from 2023 to meet the challenge of climate change. Drax aims to end its reliance on coal even quicker. Drax CEO Dorothy Thompson has talked about the possibility, given the right support, to have all coal units taken off the Drax system by 2020, if not before.

25th November 2015

The UK government cancelled its £1bn competition for CCS technology.

18th December 2015

On this day the last large scale deep coal mine in Great Britain – Kellingley in North Yorkshire – closed. UK producers were struggling to compete with lower priced, lower nitrogen oxides (NOx) emitting coal from oversees.

1st January 2016

The Industrial Emissions Directive is enforced in the UK and the rest of the European Union, putting stricter limits on the amount of NOx emitted into the atmosphere. From this point on coal power stations can either limit their availability to generate electricity or invest to adapt their boilers and use emissions abatement technologies.

May 2016

Great Britain saw its first day generating electricity without using any coal since the opening of the first UK power station in 1882.

September 2016

Drax and other energy companies write to the UK government in support of maintaining, rather than scrapping, the Carbon Price Floor.

April 2017

The first coal-free 24-hour period on Great Britain’s electricity system since 1882.

April 2018

UK government minister Claire Perry announced Drax had joined the Powering Past Coal Alliance, just three days after Great Britain’s fourth 24 hours free from the carbon-intensive fuel.

May 2019

A new coal-free record for Britain’s electricity system of 8 days, 1 hour and 25 minutes.

Present day

Drax Power Station is Europe’s largest decarbonisation project. Four of its six electricity generation units now run exclusively on biomass – reducing carbon emissions by more than 80%. Currently 75% of its electricity per year is generated using renewable, rather than fossil fuel. The last two coal units could be turned off by 2023.

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.