Tag: coal

Europe’s kicking its coal habit

19 April 2018

Power generation

From Roman mines to the fuel behind the continent-wide industrial revolution, Europe has a long history with coal. But with reducing carbon and other greenhouse gas emissions, now firmly on the global agenda, Europe’s love for coal is rapidly declining.

Collectively, the EU aims for renewable sources to account for 20% of gross final energy consumption by 2020 and 27% by 2030. Countries in and outside the EU, as well as businesses and organisations, are setting ambitious targets to phase out coal as part of the UK and Canada-led Powering Past Coal Alliance, which Drax recently signed up to.

European CountriesCoal-free date
(according to Europe Beyond Coal *updated September 2020*)
Austria 🇦🇹 2020
France 🇫🇷 2022
Portugal 🇵🇹2023
UK 🇬🇧2024
Ireland 🇮🇪 Italy 🇮🇹 2025
Greece 🇬🇷2028
Finland 🇫🇮 Netherlands 🇳🇱 2029
Denmark 🇩🇰 Hungary 🇭🇺 Portugal 🇵🇹2030
Germany 🇩🇪2038
Czech Republic 🇨🇿 Spain 🇪🇸Phase out under discussion
Bosnia Herzegovina🇧🇦 Bulgaria 🇧🇬 Croatia 🇭🇷 Kosovo🇽🇰Montenegro 🇲🇪 Poland 🇵🇱 Romania🇷🇴Serbia🇷🇸 Slovakia 🇸🇰Slovenia 🇸🇮 Spain 🇪🇸 Turkey 🇹🇷No phase out date
Belgium 🇧🇪 Cyprus 🇨🇾 Estonia 🇪🇪 Iceland 🇮🇸 Latvia 🇱🇻 Lithuania 🇱🇹 Luxembourg 🇱🇺 Malta 🇲🇹 Norway 🇳🇴 Sweden 🇸🇪Switzerland 🇨🇭No coal in electricity mix

This movement is not only being fuelled by an increased capacity in wind and solar generation, but also by other low-carbon energy sources enabling countries to kick their coal habits.

Aiming for 100% renewable

As myth after myth is dispelled about renewables, there are countries proving it is possible to power a modern developed nation entirely through renewable energy sources.

Up in the northern-most reaches of Europe, Iceland already generates all its electricity from renewable sources. This is split between 75% hydropower and 25% geothermal power. Geothermal not only offers a renewable source of electricity but also hot water for heating the volcanic island nation.

A geothermal power station steams on a cold day in Iceland

Hydropower is also a key contributor to Norway’s renewable ambitions. With more than 31 gigawatts (GW) of installed hydropower capacity, Norway is able to rely on it as a source of electricity and export its plentiful oil and natural gas reserves to countries still dependent on fossil fuels.

Many parts of Europe are well suited to hydropower, with reliable rainfall and the mountainous topography necessary to construct dams and power stations. Parts of Austria, Romania and Georgia also make substantial use of hydropower as a source of electricity.

Artificial Lake behind the Bicaz Dam at sunset, Romania

For countries without this access to large-scale hydropower, it’s the increased installation of renewables that holds the key to eliminating the need for coal.

Growing renewable generation

Last year saw electricity generation from renewable sources overtake that from coal for the first time thanks to continuous expansion of wind, solar and biomass capacity around the continent.

Between 2010 and 2017, generation from wind, solar and biomass installations in EU countries more than doubled from 302 terawatt hours (TWh) to 670 TWh, according to Eurostat, driven primarily by an increase in wind capacity. As a source of renewable electricity wind has already proved capable of generating major portions of a country’s demand –managing to meet 44% of Denmark’s overall demand in 2017. This was after previously producing a 40% electricity surplus one day for the country, allowing it to export the emission-free electricity to neighbours.

Wind turbines on the east coast of Sweden

Across the EU, generation from wind more than doubled from 150 TWh to 364 TWh from 2010 to last year, while solar generation grew five times from 23 TWh to 119 TWh and biomass jumped from 129 TWh to 196 TWh. By contrast, coal and lignite fell from 818 TWh to 669 TWh.

These renewable electricity sources, along with hydropower, now account for 30% of EU countries’ collective electricity generation. And while coal generation continues to drop, other low carbon energy sources, particularly nuclear, still play essential roles in many European energy systems.

From coal to low carbon

Sweden is one of the leaders in renewable electricity generation, setting 2040 as the date to move to totally renewable energy. However, while it currently counts 6.5 GW of wind capacity installed and has already exceeded its 2020 renewable generation goals, the country’s 10 nuclear reactors still make up 40% of its electricity output. Sweden aims to phase-nuclear out of its energy mix, but this will force it to import more power from neighbours to meet demand.

France is even more dependent, with nuclear making up 75% of its electricity production and earning more than €3 billion a year for the country in exports. It aims to reduce its nuclear generation to 50% with president Emmanuel Macron claiming continued nuclear generation offers “the most carbon-free way to produce electricity with renewables.”

Fessenheim Nuclear and Hydroelectric Power Plants in Alsace, France

As a reliable and low-carbon source of electricity, the most modern nuclear power stations add a certain amount of flexibility to grids enabling greater adoption of intermittent renewable sources. Across the EU nuclear made up a quarter of electricity generation in 2017.

Gas in the transition

Much more flexible than nuclear, gas plays an essential role in many countries. It accounted for 19% of electricity generation in the EU last year and produces around half the CO2 and just one tenth of the air pollutants of coal. Gas turbines can begin generating electricity at full power in just 30 minutes from a cold start, or 10 minutes from warm standby, allowing it to plug any gaps in demand left by intermittent renewables. Its ability to provide many system services such as reserve power and frequency response will see it play an important transition role over the coming decades, until cleaner technologies are able to take over.

Artist’s impression of a Drax rapid-response gas power station (OCGT) with planning permission

Coal is not gone yet, making up 11% of EU’s electricity generation in 2017, but the momentum behind decarbonisation is keeping Europe on track to meet its ambitious emissions target and take the final step away from coal.

The Bettercoal initiative

21 March 2018

Sustainable business

Bettercoal is a global, not-for-profit initiative that has been established by a group of major European utilities to promote the continuous improvement of corporate responsibility in the coal supply chain, with a specific focus on the mines themselves. Through membership of the Bettercoal initiative, Drax aims to ensure that the coal industry respects people’s rights and makes a positive contribution to the social and economic livelihoods of workers, producers and communities.

The Bettercoal Code sets out 10 social, environmental and ethical principles. It is not a certification body, but outlines a process for assessing coal suppliers’ performance against the ten principles. Suppliers complete self-assessment questionnaires and approved assessors conduct Bettercoal Assessments. Continuous improvement plans are developed jointly with the supplier and summary results are shared with Bettercoal members.

All Bettercoal-engaged mines sign a letter of commitment at the outset, which outlines their responsibilities. If a mine then falls short of these expectations, such as by not following up on the continuous improvement plan put in place by their auditors, then they would lose their status as a ‘Bettercoal-engaged mine’.

Drax ended its membership of Bettercoal in June 2020.

How Great Britain’s breakthrough year for renewables could have powered the past

21 February 2018

Power generation

After a year of smashing renewable records, Great Britain’s electricity system is less dependent on fossil fuels than ever before. Over the course of 2017, low-carbon energy sources, including nuclear as well as renewables, accounted for half of all electricity production.

The finding comes from Electric Insights, a quarterly research paper on Britain’s power system, commissioned by Drax and written by researchers from Imperial College London. The latest report highlights how Great Britain’s electricity system is rapidly moving away from fossil fuels, with coal and gas dropping from 80% of the electricity mix in 2010 to 50% in 2017.

It’s an impressive change for eight years, but it’s even more dramatic when compared to 60 years ago.

Powering the past with renewables

In 2017 renewable output grew 27% over 2016 and produced 96 terawatt hours (TWh) of electricity –  enough to power the entire country in 1958.

Back then Great Britain was dependent on one fuel: coal. It was the source of 92% of the country’s power and its high-carbon intensity meant emissions from electricity generation sat at 93 million tonnes of carbon dioxide (CO2). Compare that to just three million tonnes of CO2 emissions from roughly the same amount of power generated in 2017, just by renewables.     

Today the electricity system is much more diverse than in 1958. In fact, with nuclear added to renewable generation, 2017’s total low-carbon capacity produced enough power to fulfil the electricity needs of 1964’s Beatlemania Britain.

But what’s enabled this growth in renewable generation? One answer, as Bob Dylan explained a year earlier, is blowin’ in the wind.

Read the full article here: Powering the past.

Stormy weather powering Great Britain

Wind power experienced a watershed year in 2017. Thanks to blusterier weather and a wave of new wind farm installations coming online, wind generation grew 45% between 2016 and 2017.

Windfarms, both onshore and offshore, produced 15% of the entire country’s electricity output in 2017, up from 10% in 2016. The 45 TWh it generated over the course of the year was almost double that of coal – and there’s potential for this to increase in 2018 as more capacity comes online.

The 1.6 gigawatts (GW) of new offshore wind turbines installed in Great Britain last year accounted for 53% of the net 3.15 GW installed across Europe. With large offshore farms at Dudgeon and Race Bank still being commissioned, the 3.2 GW of total new operating capacity registered in 2017 across offshore as well as onshore wind is on course to grow.

Co-author of the article, RenewableUK’s Head of External Affairs Luke Clark, said:

“These figures underline that renewables are central to our changing power system. Higher wind speeds and a jump in installed capacity drove a dramatic increase in the amount of clean power generated. Alongside breaking multiple records for peak output, wind energy continued to cut costs.”

As wind power is dependent on weather conditions, it is intermittent in its generation. But in 2017, more than one storm offered ideal conditions for wind turbines. During Q4 there were three named storms as well as the remnants of a hurricane all battering the British Isles, all of which helped push average wind speeds 5% higher than in 2016. While calculating wind power based on wind speed is complex, windier weather means more power – monthly average wind speed is proportional to monthly average power output from wind farms.

While the 2017 annual average wind speed of 10.1mph, was in line with the country’s long-term average, wind generation was not consistent across the year. In Q4 wind output was close to an average of 7 GW. By contrast, between May and August it was closer to 4 GW. Thankfully these calmer months saw longer hours of daylight, allowing solar power to compensate.

Read the full article here: Wind power grows 45%

Driving down carbon emissions

The knock-on effect of an increase in renewable generation is a drop in the carbon intensity of electricity production and in 2017 this reached a new low.

Across the year, carbon emissions, including those from imported sources, totalled 72 million tonnes, down 12% from 2016. This decrease is equal to 150 kg of CO2 saved per person, or taking 4.7 million cars off the roads. The least carbon intensive period of the quarter came just after midnight in the early hours of Monday 2 October, when it measured a record low of 56 grammes per kilowatt hour (g/kWh) thanks to low fossil fuel generation and high levels of renewables.

Over the whole year there were 139 hours when carbon intensity dipped below 100 g/kWh. This generally required 50% of the electricity mix to come from renewable sources and demand to be lower than 30 GW. For carbon intensity to dip under 100 g/kWh on a more permanent basis, greater renewable capacity will be required as demand rises.

Read the full article here: Carbon emissions down 12%

Interconnectors meeting future demand

Electricity demand in Great Britain has been on the decline since 2002, primarily due to more efficient buildings and appliances, and a decline in heavy manufacturing. However, this is expected to change over the coming years as more electric vehicles are introduced and the heating system is electrified to help meet 2050 carbon emissions targets.

While installing greater renewable capacity will be crucial in meeting this demand with low-carbon power, interconnectors will also play a significant role, particularly from France, which boasts a large nuclear (and low-carbon) capacity.

However, electricity sales through interconnectors are often based on day-ahead prices rather than the live market, which can lead to trades that aren’t reflective of demand on each sides of the channel.

In Q4 there were eight half-hours when demand was very high (more than 50 GW), yet power was being exported. This occurred despite day-ahead prices suggesting traders would lose money due to lower demand in France and the cost of using the interconnector. It highlights the need for improvements in inter-network trading as Great Britain increases its intermittent renewable generation and looks to a greater reliance on importing and exporting power.

Read the full article here: Moving electricity across the channel

Great Britain’s electricity system continues to break its renewable records each year and heading into 2018 this is likely to continue. Wind and solar power will continue to grow as more installations come online and a fourth coal unit at Drax will be upgraded to sustainable biomass, which could lead to another breakthrough year. Regardless, 2017 will be a tough one to beat.

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.

How do you keep a 1.2 tonne steel ball in prime condition?

18 January 2018

Power generation

There are 600 giant balls at Drax Power Station. Each one weighs 1.2 tonnes – roughly the same as a saloon car – and is designed for one simple, but very specific, purpose: to pulverise.

Every day thousands of tonnes of biomass and coal are delivered to the power station to fuel its generators. But before this fuel can be combusted, it must be ground into a powder in pulverising mills so it burns quicker and more efficiently. It’s the giant balls that do the grinding.

And although these balls may be incredibly durable, the constant smashing, crushing and pulverising they go through on a daily basis can take its toll. Maintaining the 600 balls across the power station’s 60 mills is a vital part of keeping the plant running as effectively as possible.

Surviving the pulveriser

Each of the six generating units at Drax (three biomass and three coal) has up to 10 mills that feed it fuel, all of which operate at extreme conditions. Inside each one, 10 metal balls rotate 37 times a minute at roughly 3 mph, exerting 80 tonnes of pressure, crushing all fuel in its path.

Air is then blasted in at 190 degrees Celsius to dry the crushed fuel and blow it into the boiler at a rate of 40 tonnes per hour. To survive these extremities, the balls must be tough.

Drax works with a local foundry in Scunthorpe, Lincolnshire to manufacture them. First, they are cast as hollow orbs of nickel steel or chrome iron and then smoothed to within one millimetre of being perfectly spherical.

After 8,000 hours of use, engineers check how rapidly they’re wearing down by measuring their thickness using ultrasound equipment and, if deemed to be too thin (which usually occurs after about 50,000 hours of use), replace them.

For this, they must first remove the top of the mill – including the grinding top ring – and then individually lift out and replace each massive ball. Those that are removed are typically shipped back to Scunthorpe to be recycled.

Transforming for a decarbonised future

When Drax Power Station was first built in the 1970s, the mills were designed to only crush coal, but since it was upgraded to run primarily on biomass, in the form of sustainable wood pellets, they have been adapted to work with the new fuel.

For the most part, this requires only minor changes – the primary difference is that coal is harder to fully pulverise. Coal typically does not get entirely ground down in the first cycle, so a classifier is needed in the mill to separate the heavier particles and recirculate them for further grinding.

The process of switching one mill from biomass to coal takes about seven days and nights. This work was carried out on Unit 4’s mills ahead of this winter, following biomass trials in the spring and summer of 2017. Now that the decision has been made to permanently upgrade that fourth power generation unit, converting one of its 10 mills from coal to biomass later in 2018 will take about twice as long.

Using the same essential equipment and process for both fuels helps to quicken the pace of decarbonisation at Drax Power Station as the UK moves to end the production of unabated coal-fired electricity by 2025. Come seven years from now, one thing will remain consistent at the huge site near Selby, North Yorkshire: the giant pulveriser mills will continue their tireless, heavy-duty work.

Fourth biomass unit conversion

17 January 2018

Investors
RNS Number : 1114C
Drax Group PLC

Drax welcomes the UK Government response to the consultation on cost control for further biomass conversions under the Renewable Obligation scheme, which will enable Drax to convert a fourth unit to biomass.

The response proposes that, rather than imposing a cap on ROC(1) support for any future biomass unit conversions, a cap would be applied at the power station level across all ROC(1) units. This would protect existing converted units and limit the amount of incremental ROCs attributable to additional unit conversions to 125,000 per annum.

The response would enable Drax to optimise its power generation from biomass across its three ROC units under the cap, whilst supporting the Government’s objective of controlling costs under the Renewable Obligation scheme.

Drax will now continue its work to deliver the low cost conversion of a fourth biomass unit, accelerating the removal of coal-fired generation from the UK electricity system, whilst supporting security of supply.

Drax plans to complete the work on this unit as part of a major planned outage in the second half of 2018, before returning to service in late 2018. The capital cost is significantly below the level of previous conversions, re-purposing the existing co-firing facility on site to deliver biomass to the unit.

The unit will likely operate with lower availability than the three existing converted units, but the intention is for it to run at periods of higher demand, which are often those of higher carbon intensity, allowing optimisation of ROC(1) generation across three ROC(1) accredited units. The CfD(2) unit remains unaffected.

Will Gardiner, Chief Executive of Drax Group, commented:

“We welcome the Government’s support for further sustainable biomass generation at Drax, which will allow us to accelerate the removal of coal from the electricity system, replacing it with flexible low carbon renewable electricity.”

“We look forward to implementing a cost-effective solution for our fourth biomass unit at Drax.”

Enquiries:

Investor Relations:

Mark Strafford

+44 (0) 1757 612 491

Media:

Ali Lewis

+44 (0) 1757 612 165

 

Website: www.drax.com/uk

Notes

  1. Renewable Obligation Certificate
  2. Contract for Difference

END

 

 

Giving up coal

Tony Juniper, Author, adviser and environmental campaigner

7 December 2017

Opinion
Tony Juniper at Drax Power Station between coal stock and biomass wood pellet storage domes

Tony Juniper* is an environmental campaigner, author and director at Robertsbridge, a consultancy helping advise Drax on its sustainability programmes

Back in 2006 while working as Director at Friends of the Earth I approved a new report to be published in support of our then campaign for a new Climate Change Act. We wanted to show UK government ministers how it would indeed be possible to make cuts in emissions so that by 2050 the UK could progressively have reduced greenhouse gas pollution by 80 per cent compared with emissions in 1990. It was a radical and demanding agenda that we’d adopted and it was important to show the practical steps that could be made in achieving it.

The analysis we presented was based on an electricity sector model that we had developed. Different data and assumptions could be inputted and using this we set out six possible lower carbon futures.

In our best case scenario we foresaw how it would be feasible to slash emissions by about 70 per cent by 2030.

This was based on an ambitious energy efficiency programme and a shift away from fossil energy and toward renewables, including wind and solar power. In that renewables mix was also an important role for biomass to replace coal in the country’s largest power station – Drax.

This was not only crucial for backing up intermittent renewable sources but also a key piece in a future electricity sector that we believed should avoid the construction of new nuclear power stations. In November 2008 our campaign succeeded and the UK was the first country in the world to adopt a new national law for the science-based reduction of greenhouse gas emissions. Since then I’ve been working as an independent sustainability advisor, including with the advisory group Robertsbridge, of which I was a co-founder.

My work has included assisting various companies in meeting the targets set out in that new law. For example, I was the Chair of the industry campaign Action for Renewables which sought government and public support for the large-scale expansion of wind, tidal and wave power.

Different campaigners tried to stop the expansion of these renewable sources of electricity, however, and succeeded in derailing support for on-shore wind power developments.

Although in its infancy, concerns were also raised about proposals for different kinds of tidal power.

In the years after the Climate Change Act I was encouraged to see that Drax began to switch over to wood pellets to generate power but concerned to see that this too had come under attack. The broadly agreed view that sustainable biomass could have a role in the phase out of coal had gone, and in its place were claims  that it was actually worse than burning coal. It was against this backdrop of changed perspectives that myself and Robertsbridge colleagues were pleased to be invited to help Drax in devising a new sustainability plan.

Early on in our conversations with Drax it became clear that part of the challenge with biomass — deciding the extent to which it is a rational choice to help with the process of decarbonisation, is how the answer to that touches so many different issues.

For example, when it comes to the exit from coal, cleaner alternatives must be brought forward to replace it, including wind and solar power.

But although these sources of renewable energy are growing rapidly, they still come with their own challenges, especially because wind can’t generate on still days and solar ceases at night. This intermittency raises issues about what the best electricity storage or complementary clean power sources might be to back them up when needed.

There are important questions about the best sources of biomass and the extent to which long-distance transport of that fuel is desirable. On top of that are issues linked with the management of the forests from which the raw material is sourced, and whether the extraction of wood to generate power can be compatible with carbon neutrality. There is the matter of nature conservation and the extent to which wood fuel demand will affect the status of species and habitats of conservation concern. For example, to what extent might the wood pellet industry be driving the conversion of semi-natural woodlands to plantations?

All of this is bound up with the economic and social conditions prevailing in the landscapes from which the wood is derived and the extent to which those buying wood fuel can pursue positive outcomes for the environment, even when carbon and wildlife are at best of marginal concern to the local forest owners growing the wood.

Then there is the extent to which economic incentives might be linked with the carbon stocks held in the forest. For example, strong demand for wood is held to be the main reason why since the 1950s the volume of carbon stored in standing timber in the forests of the US South has increased by over 100%.

Demand for wood might seem counter-intuitive as a positive factor in maintaining tree cover, but in the US South it has been a big part of the picture.

On top of all this is the question of what would happen if there were no demand for wood fuel. In landscapes that have seen volatility in demand arising from the decline in newsprint in favour of digital devices and the slowdown in US house building following the 2008 financial crisis, this is not easy to answer.

Although seeking answers is a complex task, our advice to Drax was that it should work with its many stakeholders in finding the best possible fit between its business planning and these and other questions.

One way of doing that would be to set out the different issues in an accessible manner and hence the production of the film that can be seen here.

It’s called ‘The biomass sustainability story’ And while most of us can agree with the basic idea that we have to stop burning coal, it seems the big questions are about what might be the best ways to do it? Might biomass have a role? I believe it does.

Have a look at the film and see what you think, especially if you feel as though you’ve already made up your mind.

What will happen to the carbon price after 2020?

21 November 2017

Power generation

Great Britain’s electricity is cleaner than ever. As wind, solar, biomass and hydro continue to make up more and more of our energy mix, the power system edges ever closer to being entirely decarbonised. The GB power system has leapt up the big economies’ low carbon league table from 20th in 2012 to seventh in 2016.

But this shift to lower-carbon power isn’t owed only to growing renewable electricity capacity. A fall in gas prices has helped and importantly, government policy has ensured coal power generation has become increasingly uneconomical vs electricity produced with gas (gas and coal compete for contracts to supply power to the National Grid).

Introduced in 2013, Great Britain’s Carbon Price Floor sets the minimum price on carbon emissions. A stricter policy than the EU’s volatile EU Emissions Trading System (EU ETS) which puts a much lower price on carbon dioxide (CO2) emissions, the Carbon Price Support as the British policy is also known tops up the EU ETS. Together, they have had a significant impact. According to Aurora Energy Research, the Carbon Price Floor is a major factor in coal generation emissions falling.

In Great Britain, the Carbon Price Floor (CPF) is currently capped at £18 per tonne of CO2 and the EU ETS sits at around £5 t/CO2 – meaning power generators and heavy industry pay around £23 t/CO2 altogether. When initially formulated by the coalition government in 2010, it was intended the CPF would reach £30 per tonne by 2020 and £70 per tonne by 2030. However, the EU ETS has since fallen therefore the UK government chose to cap the carbon price support at £18 per tonne until 2020.

Now, as we reach the end of the decade, questions remain as to what will happen to this crucial mechanism post-2020. Will the government price coal off the system once and for all or will the fossil fuel make an unlikely comeback?

Four visions of carbon pricing’s future

In its research, Aurora has identified four potential future scenarios for the UK’s carbon pricing strategy.

Status Quo: If the UK chooses to continue supporting the phase-out of coal and promotes low-carbon investment, the Carbon Price Floor will steadily increase post-2020, reaching an estimated £52 per tonne by 2040. In this scenario the UK’s carbon pricing structure remains about £18 per tonne higher than the EU ETS which is currently around £5 per tonne.

Catch-up: In the post-Brexit landscape (whatever it may look like) the UK may choose to seek parity with the EU over decarbonisation. In this scenario, the total UK carbon price remains flat with EU ETS, which rises until convergence. In this scenario the UK and EU’s price per tonne of carbon reaches £35 by 2040.

Low Priced Carbon: In the event that the UK government removes the carbon price from 2021 and the EU ETS never recovers beyond its 2017 level, the short-term effects could be a drop in the price of coal power and cheaper energy bills. CO2 emissions increase in the UK as demand for power rises in the late 2020s and beyond (as recently witnessed in the Netherlands where coal generation has increased, in part, due to a low EU ETS). The expected price per tonne of carbon could be as low as £6 by 2040 and investment in lower carbon and renewable forms of power generation stalls.

High Priced Carbon: In order to meet the UK’s fourth and fifth carbon budgets set by the Committee on Climate Change, this scenario sees the electricity system decarbonise more quickly, with coal removed as an energy source. The carbon price rises dramatically over the next two decades to hit £153 per tonne by 2040.

Stopping the coal comeback

Of these four scenarios, the steadily increasing prices of the Status Quo scenario could see the UK meet its power sector target within the fourth carbon budget of 100 g CO2-eq/kWh  – achieving a 51% reduction from 1990 emission levels by 2030. But Aurora found that keeping things as they are could see a radical swing the other way, some years earlier in its scenario: coal could make a comeback in the early 2020s.

In July this year, coal accounted for just 2% of electricity generation in Great Britain and in 2016 as a whole it accounted for 9%, producing the lowest amount of electricity since the start of World War II. Without solid growth of the Carbon Price Floor it could become a much more competitive fuel. This potential is further increased by a predicted rise in natural gas prices post-2020, when the current surplus of liquefied natural gas (LNG) is set to end.

If the government chooses not to set tough prices on carbon emissions, Aurora predicts that on average coal will account for 9% of electricity generation between 2021 and 2025 – a change in the declining coal power trend seen in recent years. A Low Carbon Price future would see coal grow to almost 12% of the total electricity generation mix during the same period.

By contrast, in the High Carbon Price scenario, coal is almost completely driven out of the energy system, accounting for an estimated 2% of electricity generation between 2021 and 2025.

Signalling to the future

What is crucial for British power generators at this stage is clarity beyond 2020, when the £18 per tonne cap ends. This can allow the industry to react to future carbon pricing and prepare for whatever future scenario the government is most likely to adopt.

If the government chooses to continue decarbonising the energy system in a significant way – as it should do – coal facilities can be converted to renewable or lower-carbon units, such as biomass or gas. New interconnectors, renewable sources, storage facilities and demand-side response will also need to be installed at a greater capacity to meet the energy system’s demands.

As the amount of low carbon generation continues to grow, it will increasingly be the marginal generator. This means that power stations such as Drax’s biomass units, which run with an 87% lower carbon footprint compared to coal across their entire supply chain, could be used to meet the last megawatt hour (MWh) of demand – and this would see the carbon price having a diminishing impact on the wholesale price of power.

As has already been shown, the Carbon Price Floor is one of the most effective ways to reduce Great Britain’s electricity emissions. But to continue this impressive progress, the government needs to use it appropriately to set a path towards a decarbonised future.

In October, Drax joined British energy company SSE, climate NGO Sandbag and others to write to Chancellor Philip Hammond, calling on him to back the Carbon Price Floor beyond 2020 and in doing so, provide certainty for businesses investing in lower carbon and renewable capacity. Read the letter here. 

What is an ‘advantaged’ fuel, and why use them?

10 November 2017

Power generation

Drax Power Station produces 17% of the UK’s renewable electricity, but it has a long history as a coal-fired generator. And while today around 70% of Drax’s output is from renewable biomass, there are still instances when coal is used – for example, at times of high demand, such as in the winter months.

Beyond just meeting demand for power, maintaining some operational coal capacity until it can be replaced with more biomass or gas, also allows Drax to offer flexibility and grid stability through ancillary services such as inertia, reactive power and frequency management.

Ensuring these remaining coal units run as efficiently as possible is key to Drax being able to economically provide support services to the grid. And for this, alongside more conventional coals it uses something termed as advantaged fuels.

What are advantaged fuels?

Advantaged fuels are coals outside of Drax’s conventional specification that are slightly more affordable than standard coals. Blending advantaged fuels with standard coal before burning allows generators to remain economical while meeting demand.

At Drax, these include off-specification coal and mine remnants such as pond fines, which are produced from former deep mine sites . These are offered at lower prices than standard fuels because they often have a lower calorific value, meaning they produce less energy when burned, or are difficult to work with and transport.

The benefit, however, is that power stations are able to ramp up generation as well as provide essential system services while remaining economical.

Getting the balance right

Each time an advantaged fuel is used, the right blend must be found depending on how much and what type is being utilised to ensure maximum efficiency and reliability.

This requires coordination across Drax between the fuel procurement team, aiming to source these lower-priced fuels, the materials handling and power generation teams who must quickly understand and resolve any issues surrounding fuel blends and the trading team, responsible for selling into the power market.

The cost savings achieved from using advantaged fuels combined with the highly efficient units Drax Group operates, helps keep costs down and that means lower electricity costs for everyone.

But this doesn’t mean these fuels will be used for the long term. Drax is continuing to decarbonise its power generation business. At Drax Power Station where three of its six power units have been upgraded to low carbon biomass, trials were underway in the spring and summer of 2017 to test a lower cost way of converting one of the three remaining coal units to run on compressed wood pellets. The Selby, North Yorkshire site is currently consulting with its local community on plans to repower one or two coal units to run on another flexible fuel – natural gas. If constructed, the gas power plant could be joined by a large battery storage facility – one which could provide immediate power and system services to the country’s electricity system while the gas turbines power up in the minutes that follow.

Coal’s days in the UK are numbered – and this is certainly a good thing – but while it remains a necessary part of meeting winter demand and balancing the system, advantaged fuels will be key to keeping it an affordable one too.

How lasers reduce emissions

25 July 2017

Power generation
Drax laser

Of the air that makes up our atmosphere, the most abundant elements are nitrogen and oxygen. In isolation, these elements are harmless. But when exposed to extremely high temperatures, such as in a power station boiler or in nature such as in lightning strikes, they cling together to form NOx.

NOx is a collective term for waste nitrogen oxide products – specifically nitric oxide (NO) and nitrogen dioxide (NO2) – and when released into the atmosphere, they can cause problems like smog and acid rain.

At a power station, where fuel is combusted to generate electricity, some NOx is inevitable as air is used in boilers to generate heat. But it is possible to reduce how much is formed and emitted. At Drax Power Station, a system installed by Siemens is doing just that.

It begins with a look into swirling clouds of fire.

Not your average fireplace

“Getting rid of NOx is, at heart, a problem of getting combustion temperatures to a point where they are hot enough to burn fuel effectively. Too hot and the combustion will form excess amounts of NOx gases. Too cool and it won’t combust efficiently,” says Julian Groganz, a Process Control Engineer who helped install the SPPA-P3000 combustion optimisation system at Drax. “Combustion temperatures are the result of the given ratio of fuel and air in each spot of the furnace. This is our starting point for optimisation.”

An industrial boiler works in a very different way to your average fireplace. In Drax’s boilers, the fuel, be it compressed wood pellets or coal, is ground up into a fine powder before it enters the furnace. This powder has the properties of a gas and is combusted in the boilers.

“The space inside the boiler is filled with swirling clouds of burning fuel dust,” says Groganz. Ensuring uniform combustion at appropriate temperatures within this burning chamber – a necessary step for limiting NOx emissions – becomes rather difficult.

Heat up the cold spots, cool down the hotspots

If you’re looking to balance the heat inside a boiler you need to understand where to intervene.

The SPPA-P3000 system does this by beaming an array of lasers across the inside of the boiler. “Lasers are used because different gases absorb light at different wavelengths,” explains Groganz. By collecting and analysing the data from either end of the lasers – specifically, which wavelengths have been absorbed during each beam’s journey across the boiler – it’s possible to identify areas within it burning fuel at different rates and potentially producing NOx emissions.

For example, some areas may be full of lots of unburnt particles, meaning there is a lack of air causing cold spots in the furnace. Other areas may be burning too hot, forcing together nitrogen and oxygen molecules into NOx molecules. The lasers detect these imbalances and give the system a clear understanding of what’s happening inside. But knowing this is only half the battle.

A breath of fresher air

“The next job is optimising the rate of burning within the boiler so fuel can be burnt more efficiently,” explains Groganz. This is achieved by selectively pumping air into the combustion process to areas where the combustion is too poor, or limiting air in areas which is too rich.

“If you limit the air being fed into air-rich, overheated areas, temperatures come down, which reduces the production of NOx gases,” says Groganz. “If you add air into air-poor, cooler areas, temperatures go up, burning the remaining particles of fuel more efficiently.”

Drax Laser 2

It’s a two-for-one deal: not only does balancing temperatures inside the boiler limit the production of NOx gases, but also improves the overall efficiency of the boiler, bringing costs down across the board. It even helps limit damage to the materials on the inside the boiler itself.

Thanks to this system, and thanks to its increased use of sustainable biomass (which naturally produces less NOx than coal), Drax has cut NOx emissions by 53% since the solution was installed. More than that, it is the first biomass power station to install a system of this sophistication at such scale. This means it is not just a feat of technical and engineering innovation, but one paving the way to a cleaner, more efficient future.