Tag: decarbonisation

Do electric vehicles actually reduce carbon emissions?

19 August 2017

Electrification
Redcar Sunset

Electric vehicles (EVs) are often seen as a key driver towards a greener future. Indeed, transport accounts for roughly a quarter of the UK’s greenhouse gas emissions and seriously affects air quality in major cities.

To tackle pollution problems, governments around the world are implementing ambitious policies to promote the electrification of transport and phase out ICE (internal combustion engine) vehicles. The UK and France both plan to ban the sale of petrol- and diesel-only cars by 2040 while India is setting an even more ambitious end date of 2030.

Added to this are EVs’ growing popularity with drivers. There are now almost 110,000 electric cars and vans on UK roads spurred on by lowering battery costs and a growing range of models. Including plug-in hybrid vehicles, EVs now account for 2% of new registrations.

Switching to EVs is an obvious way to massively cut pollution in areas of dense traffic. But the question remains – how clean are EVs on the broader scale, when you look at the electricity used to charge them? 

Electric vehicle

Electric vehicles are getting cleaner

EVs don’t give off the same exhaust emissions as engines, but the power in their batteries has to come from somewhere. Follow the flow back from the car, through the charging point, all the way back to the power station and it’s likely some of that electricity is coming from fossil fuels. And that means emissions.

“They weren’t as green as you might think up until quite recently,” says Dr Iain Staffell, a researcher at Imperial College London and author of Electric Insights – a study commissioned by Drax that analyses electricity generation data in Britain. “Now, thanks to the rapid decarbonisation of electricity generation in the UK, EVs are delivering much better results,” he continues.

In fact, year-round average emissions from EVs have fallen by half in the last four years thanks to greener electricity generation. Today, they are twice as efficient as conventional cars.

Take the Tesla Model S. In the winter of 2012, producing the electricity for a full charge created 124g of carbon emissions per km driven, roughly the same as a 2L Range Rover Evoque. Now the carbon intensity of charging a Tesla has nearly halved to 74g/km in winter and 41 g/km in summer, as the UK continues to break its own renewable energy records. For smaller EVs, the results are even better. The Nissan Leaf and BMW i3 can now be charged for less than half the CO2 of even the cleanest non-plug-in EV, the Toyota Prius Hybrid.

Carbon intensity of electric vehicles

So, the current outlook for EVs is hugely positive – but as their numbers continue to increase, will the demand they add to the grid put their clean credentials at risk?

Will EVs accelerate electricity demand?

The National Grid suggests there could be as many as nine million EVs on UK roads by 2030, which could lead to an additional 4-10 GW of demand on the system at peak times. This, in some cases, could lead to a rise in emissions.

Electricity demand in Britain typically peaks between 6pm and 10pm, when people arrive home and switch on lights and appliances. If you were to charge your EV between those evening hours, the emissions would be 8% higher than reported in the chart above. If you charged between midnight and 6am, they would be 10% lower.

Today, this demand is met by the existing mix of power stations (which last quarter included more than 50% renewable and low-carbon sources). But when there are sudden spikes in demand above this typical usage, the National Grid must call in the help of carbon-intensive reserve generators, such as coal-powered stations. Polluting diesel generators are also on standby around the UK, ready to turn on and feed into regional distribution grids at a moment’s notice.

To meet the challenge of peak-time EV charging, less carbon intensive power generation, storage and smart power management systems are needed. These include rapid response gas power stations such as the four Drax OCGTs planned to come online in the early 2020s, as well as grid-scale batteries, home-based batteries and demand-side response schemes. As the share of intermittent renewable capacity on the grid increases, more back-up power needs to be available for when the wind doesn’t blow and the sun doesn’t shine.

Keeping our future fuels clean

A future increasingly relying on back-up generators is far from inevitable, especially if the use of smart technology and smart meters increases. By analysing electricity costs and country-wide demand, smart meters have the potential to ensure EVs only charge outside peak times (unless absolutely necessary), when electricity is more likely to come from renewable or low-carbon and cheaper sources.

If the grid continues to decarbonise through advances in renewable technologies and lower-cost coal-to-biomass conversions, the potential of EVs’ electricity coming with associated emissions is diminished even further.

There is no doubt that EVs will make up a significant part in the future of our mobility. That they will also play a part in the future of cleaning up that mobility is as good as assured, but on this journey, it’s imperative we keep our eyes on the road.

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 you need to know about Britain’s electricity last quarter

17 August 2017

Power generation
Drax EI header

For an hour over lunch on Wednesday, 7th June, more than 50% of Britain’s electricity came from renewables. It was only the second time this had ever happened – the first had come just two months earlier, in April.

The second quarter (Q2) of 2017 was a period largely made up of firsts for Britain’s electricity system. While there were only two instances of renewable power tipping the 50% mark between April and June, overall, wind, solar, biomass and hydro energy made up more than a quarter of all Britain’s electricity for the first time ever.

These findings come from Electric Insights, research on Britain’s power system, commissioned by Drax and written by top university academics. Over the past year, the quarterly report has shown breaking renewable records is becoming the new normal for Britain’s electricity. Last quarter was no different.

Here, we look at the key findings from Q2 2017 and what they mean for the changing nature of the energy sector.

Daily electricity generation graph

More than half Great Britain’s electricity came from renewables. Twice

Wind, solar, biomass and hydro accounted for 51.5% of the UK’s electricity for an hour on 7th June, generating 19.1 gigawatts (GW). Combined with nuclear power and imports from France, low-carbon output was a record 28.6 GW – a massive 89% of total demand. This followed 30th April, when Britain’s electricity edged over the 50% renewable mark for a shorter, but no less significant, period.

The percentage of renewables making up our power supply is set to grow as additional renewable capacity comes onto the grid. There is currently 6 GW of additional wind capacity being constructed in Britain. Solar capacity has already hit 12.4 GW – more solar panels than analysts thought would be installed by 2050. Plans to convert more of Britain’s coal units to biomass will increase the availability of renewable power further, still.

25% electricity infographic

Electricity was cleaner than ever

There was a key date in the history of coal during Q2. On 21st April, Britain recorded the first full day it had gone without burning any coal since 1882 – the year Holborn Viaduct power station became the world’s first coal-fired public electricity station.

While that date is symbolic of the UK’s shift away from coal, in practice, it means carbon emissions are also dropping to historically low levels. Carbon intensity reached a new low in Q2, averaging 199 g/kWh over the quarter – 10% lower than the previous minimum set last year. For context, carbon intensity averaged 740 g/kWh in the 1980s and 500 g/kWh in the 2000s.

An important indicator of this falling carbon intensity is that Britain’s electricity now regularly drops below 100 g/kWh, and reached an all-time low of 71 g/kWh on the sunny and windy Sunday of 11th June.

100,000 electric vehicles infographic

Electric cars are cleaner than before

One of the greatest decarbonisation challenges moving forward is how we transform transport. Electrification is the primary driver of change in this sector, and Q2 saw Britain hit a significant milestone as the total number of electric vehicles (EVs) in the country surpassed 100,000.

The potential of EVs in cleaning up transport is significant, but there are also concerns they could, in some cases, increase CO2 levels due to pollution from power stations. However, as the last quarter’s data shows, EVs are in fact twice as carbon efficient as conventional cars thanks to the amount of renewable and low carbon electricity on the system.

“According to our analysis, looking at a few of the most popular models, EVs weren’t as green as you might think up until quite recently,” says Dr Iain Staffell From Imperial College London. “But now, thanks to the rapid decarbonisation of electricity generation in the UK they are delivering much better results.”

25% solar infographic

The most solar power a quarter has ever seen

The longer days in Q2 enabled solar power to become a key source of electricity, and for eight hours over the quarter it generated more than all fossil fuels combined. It also set output records by supplying 25% of total demand on 8th April, and producing 8.91 GW on 26th May.

While wind remains the largest source of renewable energy generation in the UK, solar’s influence is growing – especially as decentralisation of the power system continues to proliferate.

Of Britain’s 12.4 GW solar capacity, 57% is concentrated in 1,400 solar farms of around 5 MW each, while the rest is distributed across almost one million rooftop arrays in homes, businesses and other institutions. In fact, during June, 10% of all Britain’s electricity came from these sorts of decentralised sources – sources of power not on the national grid.

This is unlikely to spell a fundamental shift to an entirely decentralised power grid in the short term, but it does hint at the changes the sector is seeing. From its carbon profile, to its variety, to its flexibility, Britain’s power system is changing – and that’s a good thing.

10% decentralised energy infographic

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.

A flexible energy future

Andy Koss, CEO Generation until April 2020

3 August 2017

Opinion

Renewable technologies now account for a larger proportion of Great Britain’s electricity sources than ever before. And they’re growing.

The first quarter of 2017 was another record-breaking one for renewables. Biomass, wind and hydro all registered their highest energy production ever, while solar recorded its highest ever peak output. Drax’s own generation is now 68% renewable and accounted for 17% of the country’s overall renewable generation in the first half of 2017 – enough to power over four million homes.

We’ve made great progress over a relatively short period. However, with every step forward we need to ensure our approach is helping enhance stability. In a power system increasingly made up of intermittent renewables, what will become more and more important for security of electricity supply will be technologies that respond quickly to spikes in demand and drops in supply – for example, when the sun isn’t shining and the wind isn’t blowing.

In short, what the power system of today needs is flexibility.

 The flexibility factor

A recent report by Imperial College London for the Committee on Climate Change (CCC) highlights the significance of increasing system-wide flexibility in achieving decarbonisation. Imperial’s analysis emphasises the cost savings this can have, projecting that flexibility in a 50 g/kWh system – the lower-end of the CCC’s 2030 target for a decarbonised system – could save between £7.1 billion and £8.1 billion a year in system integration costs.

Without flexibility, the costs of balancing the system will rise significantly. This, in turn, could lead to the current fast-pace of grid decarbonisation stalling.

The need for flexibility in our energy system is too financially and environmentally significant to ignore. But what sources and technologies will we need to create it?

The next big thing in system flexibility

There are a number of technologies that are often touted as key to a flexible system, including storage (principally batteries), interconnectors, rapid response gas plants, renewable technologies such as biomass, and demand side response. All are indeed crucial to a flexible future, but alone each one still has its challenges.

Millions of pounds are being invested in battery and storage research – both in the ambition of driving down costs and in increasing capacity. However, there is a way to go on both fronts. For example, consider the scale at which batteries must operate.

The storage domes at Drax Power Station hold up to 300 kt of wood pellets – enough to generate roughly 600 GWh of electricity. At the current battery prices of around £350 per kWh it would cost £210 billion to replace their capacity with batteries. Even if prices fell dramatically we are still talking about a £60 billion price tag.

Greater interconnection is something energy industry regulator Ofgem and the National Infrastructure Commission (NIC) are calling for, but National Grid has voiced concerns that wholesale market price swings could lead to changes in power flows across interconnectors. This, in turn, could impact Great Britain’s system.

However, they remain a potential solution to solving flexibility, not just for their ability to deliver power, but in their ability to deliver ancillary services – something which will become increasingly important in a more volatile power system. For example, if built, Hinkley Point C will have some of the biggest single units on the system (1,600 MW), which will create more demand for ancillary services such as frequency response.

Technologies such as biomass and gas are well placed to provide this as well as quickly respond to changes in demand and supply. They also highlight why it is important to consider each megawatt coming onto the system. Not all technologies offer electricity and system stability tools (ancillary services), and so each one should be assessed from a whole system cost perspective, and according to how they fit into the overall supply mix.

Each type of generation can bring diverse services, so to achieve true flexibility we can’t rely on one technology – instead, we will need to rely on many.

Better together

To achieve full system flexibility we will need a coordinated combination of sources. This means maintaining a stable system that includes increasing levels of intermittent renewables, and flexible generation sources like biomass and gas that will supply baseload megawatts, plug the gaps left by intermittent renewables, and provide ancillary services.

The four rapid response gas power plants we are developing will play a key role once they are consented, secure Capacity Market contracts and become operational in the early 2020s. They will be crucial to plugging gaps in power supply as a result of unfavourable weather conditions.

Creating a system that is sufficiently flexible will make Britain much more effective in responding to stresses such as very low wind speeds over several hours, unexpected power station unit outages, or high demand. More than this, it will keep us on track to meeting carbon-reduction challenges.

For an affordable, decarbonised power system we need to be stable. To be stable we need to be flexible. And to be flexible we need to be varied and we need to work together.

How quickly will these countries reach their climate targets?

28 June 2017

Power generation

It was no surprise when President Donald Trump echoed his election campaign stance and announced his intention to renegotiate – or failing that withdraw the US – from the Paris Agreement on Climate Change. It raised the question, would other countries back away from their own climate change targets?

In fact, many reaffirmed their commitment to the pact and continue their progress towards becoming low carbon economies. For those in the European Union, this means meeting the 2030 climate and energy framework, which sets three key targets for member states: cut greenhouse gas (GHG) emissions by at least 40% from 1990 levels, produce at least 27% of their energy through renewable sources, and improve energy efficiency by at least 27%.

Many countries across Europe, however, have set climate objectives that go beyond these. Whether they can meet those goals is another matter.

Portugal

What are its climate targets?

The Portuguese government has pressed the EU to go further than its 2030 targets and is aiming for 40% of total energy consumption to come from renewables by 2030. This target is part of its Green Growth Commitment 2030, which also sets out to create more green – or low carbon economy – jobs and improve overall energy efficiency across the country.

How is it achieving this?

Portugal has rapidly increased its renewable energy production by investing in wind (mainly onshore) and hydro power, although it is rapidly developing its solar capabilities. It is also looking at small scale renewable energy generation through wave, thermal and biomass power.

Portugal has two operational coal plants that together are responsible for 16% of the country’s carbon emissions. However, the government is seeking to phase these out prior to 2025.

How is it doing so far?

The growth in renewable energy within the power industry specifically has been a big success story for Portugal. In 2005, renewables accounted for only 16% of total electricity production – by 2015 they produced an average of 52%.

The country made headlines in May 2016 for running on 100% renewable electricity for four days in a row. Unsurprisingly, this means the government is confident of achieving a target of 31% renewables in gross final energy consumption by 2020, which would mean 57.4% renewable electricity generation.

Germany

What are its climate targets?

Germany set its current climate targets as far back as 2007. It subsequently agreed to the Paris Agreement and the EU’s 2014 climate and energy framework.

Added to this, the country has its own ambitious aims for 2050: cut GHG emissions by up to 95% compared to 1990 levels (with an interim target of 40% by 2020), increase the share of renewables in gross final energy consumption to 60%, and increase all electricity generated from renewables to 80%.

How does it plan to achieve this?

Germany’s Climate Action Programme 2020 and Climate Action Plan 2050, set out its plans for reducing GHG emissions. Much of this is based around the Energiewende (energy transition), a strategy that will see the country phase-out nuclear power and decarbonise the economy through renewable energy initiatives.

According to these plans, Germany’s energy supply must be almost completely decarbonised by 2050, with coal power slowly phased out and replaced with renewables, especially wind power. The utilisation of biomass will be limited and sourced mostly from waste. It also stresses the role of the European Union Emission Trading System to meet targets.

How is it doing so far?

Between 1990 and 2015, emissions reduced by 27%. In 2015, the share of renewable sources in German domestic power consumption amounted to 31.6%.

However, German energy-related CO₂ emissions rose almost 1% in 2016, despite a fall in coal use and the ongoing expansion of renewable energy sources. This rise is due in part to an overall increase in energy consumption and an increase in natural gas use and diesel for electricity, heat and transport.

Projections from the environment ministry in September 2016 indicated that Germany will likely miss its 2020 climate target.

UK

What are its climate targets?

Alongside its EU and Paris commitments, the UK Houses of Parliament approved the Climate Change Act in 2008, which commits to reducing GHG emissions by at least 80% of 1990 levels by 2050.

The Act requires the government to set legally-binding carbon budgets, a cap on the amount of GHG emitted in the UK over a five-year period. The first five carbon budgets have been put into legislation and will run up to 2032. These include reducing emissions 37% below 1990 levels by 2020 and 57% by 2030.

A key milestone in the UK’s decarbonisation is to entirely phase out coal by 2025, which will mean either closing or converting (as in the case of Drax Power Station) existing coal power stations.

How does it plan to achieve this?

Under its legally binding carbon budget system, every tonne of GHG emitted between now and 2050 will count. Where emissions rise in one sector of the economy (be it agriculture, heavy industry, power, transport, etc.), the UK must achieve corresponding falls in another.

The UK’s initial focus has been to transition to renewable electricity production. Wind, biomass and solar power have all grown significantly, aided by government support, and by initiatives like the carbon price floor.

How is it doing so far?

The UK’s progress towards its targets is positive, but leaves room for improvement. Renewables generated 14.9% of the UK’s electricity in 2013. In 2015 they accounted for nearly a quarter of electricity generation and by 2016, low carbon power sources contributed an average of 40% of the UK’s power, with wind generating more power than coal for the first time ever.

The Department for Business, Energy and Industrial Strategy estimates that as of 2016 GHG emissions fell 42% since 1990. Despite this, the Committee on Climate Change (CCC) has said that the government is not on track to meet its pledge of cutting emissions 80% by 2050.

However, it points out the UK is likely to meet the target of making electricity almost entirely low-carbon by early 2030s, but only if further steps are taken such as including increasing investment in more low-carbon generation (such as biomass), and developing carbon capture and storage (CCS) technologies. The UK government is due to publish an emissions reduction plan in the autumn of 2017. 

Norway

What are its climate targets?

Norway’s climate policy is based on agreements reached in the Storting (the Norwegian Parliament) in 2008 and 2012. They stipulate a commitment to reduce global GHG emissions by at least 30% by 2020 from 1990 levels. The government also approved the goal of achieving carbon neutrality by 2050.

As well as signing the Paris Agreement, Norway has aligned itself with the European Union’s climate target and intends to fulfil its commitment collectively with the EU (of which it is not a member state). This means using the EU emissions trading market, international cooperation on emissions reductions, and project-based cooperation.

How does it plan to achieve this?

Around 98% of Norway’s electricity production already comes from renewable energy sources, mostly through its more than 900 hydropower plants. The remainder is through wind and thermal power.

Norway exports hydropower to the Netherlands and exchanges renewable energy with Denmark, Sweden and Finland. There are plans for similar green exchanges with Germany and the United Kingdom via interconnectors within the next five years.

Norway is also aided by a substantial carbon sink in its forests which cover 30% of its land surface. They sequester (absorb and store) carbon from the atmosphere to such an extent that it equals approximately half of the Scandinavian country’s annual emissions.

How is it doing so far?

While Norway already has one of the world’s most carbon neutral electricity sectors, its significant domestic oil and gas sector means it still struggles to reduce its overall emissions. As such, the government is expected to rely on carbon trading with the EU or international offsets to meet its ambitious goals.

Nonetheless, earlier this year the government said that GHG emissions will fall to around 1990 levels by 2020, although it did not stipulate whether this included buying carbon credits from abroad or not.

3 ways decarbonisation could change the world

27 June 2017

Sustainable business

Mitigating climate change is a difficult challenge. But it’s one well within the grasp of governments, companies and individuals around the world if we can start thinking strategically.

On the behalf of the German government, The Internal Energy Agency (IEA) and the International Renewable Energy Agency (IRENA) have jointly published a report outlining the long-term targets of a worldwide decarbonisation process, and how those targets can be achieved through long-term investment and policy strategies.

At the heart of the report is a commitment to the ‘66% two degrees Celsius scenario’, which the report defines as, ‘limiting the rise in global mean temperature to two degrees Celsius by 2100 with a probability of 66%’. This is in line with the Paris Agreement, which agreed on limiting global average temperature increase to below two degrees Celsius.

Here are three of the findings from the report that highlight how decarbonisation could change the world.

The energy landscape will change – and that’s a good thing

Decarbonisation will by definition mean reducing the use of carbon-intensive fossil fuels. Today, 81% of the world’s power is generated by fossil fuels. But by 2050, that will need to come down to 39% to meet the 66% two degrees Celsius scenario, according to the report. But, this doesn’t mean all fossil fuels will be treated equally.

Coal will be the most extensively reduced, while other fossil fuels will be less affected. Oil use in 2050 is expected to stand at 45% of today’s levels, but will likely still feature in the energy landscape due its use in industries like petrochemicals.

Gas will likely also remain a key part of the energy makeup, thanks to its ability to provide auxiliary grid functions like frequency response and black-starting in the event of grid failure.

Renewables like biomass will likely play an increasing role here as well, particularly when combined with carbon capture and storage (CCS) technology.

Overall, renewable energy sources will need to increase substantially. In the report’s global roadmap for the future, renewables make up two thirds of the primary energy supply. Reaching this figure will be no mean feat – it will mean renewable growth rates doubling compared with today.

Everyday electricity use will become more efficient 

The report highlights the need for ‘end-use’ behaviour to change. This can mean everyday energy users choosing to use a bit less heat, power and fuel for transport in our day-to-day activities, but a bigger driver of change will be by investment in better, more efficient end-use technology – the technology, devices and household appliances we use every day.

In fact, the study argues that net investment in energy supply doesn’t need to increase beyond today’s level – what needs to increase is investment in these technologies. For instance, by 2050, 70% of new cars must be electric cars to meet decarbonisation targets.

Infrastructure design could also be improved for energy efficiency – smart grids, battery storage and buildings retrofitted with energy efficient features such as LED lighting will be essential. There’s also the possibility of increased use of cleaner building materials and processes – for example, constructing large scale buildings out of wood rather than carbon-intensive materials such as concrete and steel.

Decarbonisation will cost, but not decarbonising will cost more

The upfront costs of meeting temperature targets will be substantial. A case study used in the report estimates that $119 trillion would need to be spent on low-carbon technologies between 2015 and 2050. But it also suggests another $29 trillion may be needed to meet targets.

However, failure to act could mean the world will pay out an even higher figure in healthcare costs, or in other economic costs associated with climate change, such as flood damage or drought. Therefore, the sum for decarbonisation could end up costing between two and six times less than what failing to decarbonise could cost.

On top of this, the new jobs (including those in renewable fuel industries that will replace those lost in fossil fuels) and opportunities that will be created between 2015 and 2050 could add $19 trillion to the global economy. More than that, global GDP could be increased by 0.8% in 2050, thanks to added stimulus from the low carbon economy.

Achieving a cleaner future won’t be easy – it requires planning, effort, and the will to see beyond short-term goals and think about the long-term benefits. But as the report demonstrates, get it right and the results could be considerable.

Everything you ever wanted to know about cooling towers

17 May 2017

Power generation
Close up image of Drax cooling tower

Cooling towers aren’t beautiful buildings in the traditional sense, but it’s undeniable they are icons of 20th century architecture. They’re a ubiquitous part of our landscape – each one a reminder of our industrial heritage.

Yet despite the familiarity we have with them, knowledge about what a cooling tower actually does remains limited. A common misconception is that they release pollution. In fact, what they actually release is water vapour – similar to, but nowhere near as hot, as the steam coming out of your kettle every morning. And this probably isn’t the only thing you never knew about cooling towers. 

What does a cooling tower do?

As the name suggests, a cooling tower’s primary function is to lower temperatures – specifically of water, or ‘cooling water’ as it’s known at Drax.

Power stations utilise a substantial amount of water in the generation of electricity. At a thermal power plant, such as Drax, fuel is used to heat demineralised water to turn it to high pressure steam. This steam is used to spin turbines and generate electricity before being cooled by the cooling water, which flows through two condensers on either side of each of the steam turbines, and then returning to the boiler. It is this process that the cooling towers support – and it plays a pivotal role in the efficiency of electricity generation at Drax’s North Yorkshire site.

To optimise water utilisation, some power stations cycle it. To do this, they have cooling towers, of which at Drax there are 12. These large towers recover the warmed water, which then continues to be circulated where chemistry is permitting.

The warmed water (about 40°C) is pumped into the tower and sprayed out of a set of sprinklers onto a large volume of plastic packing, where it is cooled by the air naturally drawn through the tower. The plastic packing provides a large surface area to help cool the water, which then falls in to the large flat area at the bottom of the massive structure called the cooling tower pond.

As the water cools down, some of it (approximately 2%) escapes the top of the tower as water vapour. This water vapour, which is commonly mistakenly referred to as steam, may be the most visible part of the process but it’s only a by-product of the cooling process.

The majority of the water utilised by Drax Power Station is returned back to the environment, either as vapour from the top of the towers or safely discharged back to the River Ouse. Each year, about half of the water removed from the river is returned there. In effect, it is a huge amount of water recycling and in environmental terms, it is not a consumptive process.

Close-up of side of Drax cooling towers

How do you build a cooling tower?

The history of cooling towers as we know them today dates back to the beginning of the 20th century, when two Dutch engineers were the first to build a tower using a ‘hyperboloid’ shape. Very wide on the bottom, curved in the centre and flared at the top, the structure meant fewer materials were required to construct each tower, it was naturally more robust, and it helped draw in air and aid its flow upwards. It quickly became the de facto design for towers across the world.

The Dutch engineers’ tower measured 34 metres, which at the time was a substantial achievement, but as engineering and construction abilities progressed, so too did the size of cooling towers.

Today, each of 12 towers measures 115 metres tall – big enough to fit the dome of St Paul’s Cathedral or the whole of the Statue of Liberty, with room to spare. If scaled down to the size of an egg, the concrete of each cooling tower would be the same thinness as egg shell.

The structures at Drax are dwarfed by the cooling towers at the Kalisindh power plant in Rajasthan, India, the tallest in the world. Each stands an impressive 202 metres tall – twice the height of the tower housing Big Ben and just a touch taller than the UK’s joint fifth tallest skyscraper, the HSBC Tower at 8 Canada Square in London’s Canary Wharf.

The industrial icon of the future

Today’s energy mix is not what is used to be. The increased use of renewables means we’re no longer as reliant on fossil fuels, and this has an effect on cooling towers. Already a large proportion of the UK’s most prominent towers have been demolished, going the same way as the coal they were once in service to. But this doesn’t mean cooling towers will disappear completely.

Power stations such as Drax, which has upgraded four of its boilers to super-heat water with sustainably-sourced compressed wood pellets instead of coal, the dwindling coal fleet, and some gas facilities still rely on cooling towers. As they continue to be part of our energy mix, the cooling tower will remain an icon of electricity generation for the time being. But it’ll be a mantle it shares with biomass domes, gigantic offshore wind turbines and field-upon-field of solar panels – the icons of today’s diverse energy mix.

View our water cooling towers close up. Drax Power Station is open for individual and group visits. See the Visit Us section for further information.

Why you shouldn’t be surprised by another record-breaking quarter for renewable energy

11 May 2017

Power generation
Field of solar panels shot from above

It’s been another record-breaking quarter for Britain’s power system. During the first three months of 2017, biomass, wind and hydro all registered their highest energy production ever, while solar recorded its highest ever peak output.

And while this is all worth celebrating, it shouldn’t come as a surprise – the last few years have seen Britain’s power system take several significant steps toward decarbonisation and this year is no different. Electric Insights, the quarterly report on Britain’s power system by Dr Iain Staffell from Imperial College London, commissioned by Drax via Imperial Consultants, documents the new gains and confirms the trend: renewables are fast becoming the new norm and in 2017 they continued their growth.

Biomass domes at Drax Power Station

The renewable record breakers

Over this quarter biomass electricity generation hit a record production figure of 4.4 TWh, which means that biomass generators ran at 95% of full capacity – higher than any other technology has achieved over the last decade.

Hydro went 4% better than its previous energy production best by generating 1.6 TWh, while Britain’s wind farms produced 11.3 TWh (10% higher than the previous record, set in 2015). This was helped in part by several new farms being built which increased installed capacity by 5% over last year, but it was also indebted to the mild, windy weather.

Wind farms produced more electricity than coal, 57 days out of 90 during the first three months of 2017

Solar hit a new record peak output at the end of March, when it generated 7.67 GW – enough to power a fifth of the country. In fact, during the last weekend of March, for the first time ever, the country’s demand for electricity from the national grid was lower during an afternoon than during the night. This was because solar panels, which only generate power when the sun is up, tend to sit outside of the national high voltage transmission grid.

Understanding how this happened is to understand how solar energy is changing our national power system.

A reverse of the trend

Electricity demand on the national grid – think of it as the power system’s motorways – is typically higher during the day and early evening (when people are most active, using lights and gadgets) than overnight. However, on the last weekend in March 2017, the opposite was true because of how much solar energy was generated.

Solar panels and some smaller onshore windfarms are ‘invisible’ – they don’t feed into the national grid. Instead, these sources either feed into the regional electricity distribution networks – the power system’s A and B roads – or, as many of them are on people’s roofs and used in their own homes or business premises, it never gets down their driveway. This can mean when solar panels are generating a lot of electricity, there is a lower demand for power from the grid, making it appear that less of the country is using electricity than it actually is.

This was the case during the last weekend of March, when solar generated enough power to satisfy a large part of Britain’s demand. And while this is another positive step towards a lower carbon energy mix, it is about to change the way our power system works, particularly when it comes to the remaining coal power stations.

What the power system needs to provide, today and in the future, is flexibility – to ramp up and down to accommodate for the shifting demand based on supply of intermittent – weather dependent – renewables. Thermal power stations such as gas, coal and biomass can meet much of this demand, but even more rapid response from technologies such as the Open Cycle Gas Turbines that Drax is developing and batteries could fulfil these needs quicker.

Today’s dirty is yesterday’s clean

The record breaking and increased renewable generation of the period from January to March 2017 would mean nothing if it wasn’t matched by a decrease in emissions. During the first three months of 2017, emissions dropped 10% lower than the same period in 2016 and a massive 33% lower than 2015. Coal output alone fell 30% this quarter compared to Q1 2016.

To put the scale of this progress into context we need only look at the quarter’s ‘dirtiest hour’ – the hour in which carbon intensity from electricity generation is at its highest. Between January and March, it peaked on a calm and cold January evening with 424 grams of CO2 released per kWh (g/kWh). The average for generation between 2009 and 2013 was 471 g/kWh. In short, this quarter’s dirtiest hour was cleaner than the average figure just four years ago – yesterday’s average is today’s extremity.

If we want to continue to break records and further progress towards a fully decarbonised power system, this needs to be a consistent aim: making the averages of today tomorrow’s extremes.

Top line stats

Highest energy production ever

  • Wind – 11.3 TWh
  • Biomass – 4.4 TWh
  • Hydro – 1.6 TWh

Record peak output

  • Solar – 7.67 GW
  • Enough to power 1/5 of the country

Yesterday’s average is today’s extremity

  • Average carbon emissions per kWh – 2009-2013
    • 471 g/kWh
  • Average carbon emissions per kWh – Q1 2017
    • 284 g/kWh
  • Peak carbon emissions per kWh – 2009-2013
    • 704 g/kWh
  • Peak carbon emissions per kWh – Q1 2017
    • 424 g/kWh

 

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.

More power per pound

23 March 2017

Sustainable bioenergy

As the country moves towards a lower carbon future, each renewable power generation technology has its place. Wind, solar, hydro and wave can take advantage of the weather to provide plentiful power – when conditions are right.

Reliable, affordable, renewable power

But people need electricity instantly – not just when it’s a windy night or a sunny day. So, until a time when storage can provide enough affordable capacity to store and supply the grid with power from ample solar and wind farms, the country has to rely, in part, on thermal generation like gas, coal and biomass. Reliable and available on demand, yes. But renewable, low carbon and affordable too? It can be.

A year ago, a report by economic consultancy NERA and researchers at Imperial College London highlighted how a balanced mix of renewable technologies could save bill payers more than £2bn. Now, publicly available Ofgem data on which its newly published Renewables Obligation Annual Report 2015-16 is based reinforces the case for government to continue to support coal-to-biomass unit conversions within that technology mix. Why? Because out of all renewables deployed at large scale, biomass presents the most value for money – less public funding is required for more power produced.

Renewable costs compared

Drax Power Station’s biomass upgrades were the largest recipient of Renewable Obligation (RO) support during the period 2015-16. The transformation from coal to compressed wood pellets has made Drax the largest generator of renewable electricity in the country. And by a significant margin. Drax Power Station produced more than five times the renewable power than the next biggest project supported under the RO – the London Array.

Dr Iain Staffell, lecturer in Sustainable Energy at the Centre for Environmental Policy, Imperial College London, and author of Electric Insights, who has analysed the Ofgem data commented:

“Based on Ofgem’s Renewables Obligation database, the average support that Drax Power Station received was £43.05 per MWh generated. This compares to £88.70 per MWh from the other nine largest projects.”

“Biomass receives half the support of the UK’s other large renewable projects, which are all offshore wind. The average support received across all renewable generators in the RO scheme – which includes much smaller projects and all types of technology – is £58 per MWh. That is around £15 per MWh more than the support received by Drax.”

Ending the age of coal

Drax Group isn’t arguing for limitless support for coal-to-biomass conversions. And Drax Power Station, being the biggest, most modern and efficient of power stations built in the age of coal, is a special case. But if the RO did exist just to support lots of biomass conversions like Drax but no other renewable technologies, then in just one year, between 2015-16, £1bn of costs saving could have been made for the public purse.

Drax Power Station may be the biggest-single site recipient of support under the RO – but it does supply more low carbon power into the National Grid than any other company supported by Renewable Obligation Certificates (ROCs). In fact, 65% of the electricity generated at its Selby, North Yorkshire site, is now renewable. That’s 16% of the entire country’s renewable power – enough to power four million households.

Thanks to the support provided to Drax by previous governments, the current administration has a comparatively cost effective way to help the power sector move towards a lower carbon future. Biomass electricity generated at Drax Power Station has a carbon footprint that is at least 80% less than coal power – supply chain included. Drax Group stands ready to do more – which is why research and development continues apace at the power plant. R&D that the company hopes will result in ever more affordable ways to upgrade its remaining three coal units to sustainably-sourced biomass, before coal’s 2025 deadline.

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.

Taxing coal off the system

13 March 2017

Power generation

In the Spring Budget 2017, the Chancellor announced that the Government remains committed to carbon pricing. Philip Hammond’s red book revealed that from 2021-22 ‘the Government will target a total carbon price and set the specific tax rate … giving businesses greater clarity on the total price they will pay.’ Further details on carbon prices are to be ‘set out at Autumn Budget 2017’.

Researchers at Imperial College London have modelled what would have happened during 2016 with no carbon tax and also with an increased carbon tax. They have compared both with what actually happened. Their conclusion?

No carbon tax would mean:

  • More coal
  • Less gas
  • Higher emissions.

A higher carbon tax would mean:

  • Less coal
  • More gas
  • Lower emissions

Since it was announced in 2011, the Carbon Price Support (CPS) has encouraged generators and industry to invest in lower carbon and renewable technologies. It has also forced coal generators to fire their boilers only when they are really needed to meet demand, such as during the winter months or at times of peak demand and still or overcast weather conditions during the summer months.

The introduction of the carbon price has meant that gas power stations, which are less carbon intensive than coal, have jumped ahead of coal in the economic merit order of energy generation technologies and produced a greater share of the UK’s power. The same is the case for former coal generation units that have since upgraded to sustainable biomass – three such units at Drax Power Station result in savings in greenhouse gas (GHG) emissions of at least 80%.

A coal cliff edge?

The Carbon Price Support has resulted in significant savings in the country’s greenhouse gas emissions, helping the UK meet its international climate change commitments. Removing or reducing the CPS too soon and Britain’s power mix risks going back in time. It would improve the economics of coal and encourage Britain’s remaining coal power stations to stay open for longer creating a risk to security of supply through a ‘cliff edge’ of coal closures in the mid-2020s. Changing the economics to favour coal also makes it harder to reach the UK government’s goal of bringing a new fleet of gas power stations online.

What if …

Dr Iain Staffell from the Centre for Environmental Policy at Imperial College London has modelled a scenario in which the Carbon Price Support did not exist in 2016. “If the government had abolished all carbon pricing, we would probably have seen a 20% increase in the power sector’s carbon emissions,” said Staffell.

“Removing the Carbon Price Support would have the equivalent environmental impact of every single person in the UK deciding to drive a car once a year from Land’s End to John o’Groats.”

Without the Carbon Price Support, emissions from electricity consumption would be 20% higher, meaning an extra 250 kg per person (equivalent to driving a car 800 miles).

Running the numbers

The Carbon Price Support is capped at £18/tCO2 until 2021. In his Budget on 8th March 2017, Chancellor Philip Hammond – rightly, in the view of Drax – confirmed the government’s commitment to carbon pricing. Using data from National Grid and Elexon and analysis from Dr Iain Staffell, Electric Insights shows how coal power generation was only needed last winter when electricity demand was greater than could be produced by other technologies alone. Coal was only used at times of peak demand because it was among the most expensive energy technologies, in part due to the CPS.

What if that wasn’t the case and the government had decided to scrap the CPS before that point in time? More coal is burnt, particularly during the daytimes – on average coal produces 2,500 MW more over this week (equivalent to four of Drax Power Station’s six generation units).

And what does Dr Iain Staffell’s model suggest would have happened if the cap was doubled to £36/tCO2? The change is stark. Even for a week in the winter, with an average temperature across the country of 8.6oC, to see coal generation reduced so much compared to the actual CPS of £18/tCO2 or the £0/tCO2 scenario model, illustrates the impact of the Carbon Price Support.

Could bill payers save?

One argument for reducing the Carbon Price Support – or scrapping it altogether – is the possibility that consumers and non-domestic electricity bill payers would save money. It’s worth noting that apparent savings for electricity bill payers are lowered when the whole way that power is priced is accounted for, by the time it reaches homes and businesses.

“Carbon price support does increase the cost of wholesale power,” says Staffell. “But if you add the extra taxes, other renewable and low carbon support measures, transmission and balancing charges and fees imposed by electricity suppliers, the overall impact on consumer bills is modest. So, if the government abolished all carbon pricing, we could expect a 1 p/kWh reduction in our tariffs, but a 21% increase in our carbon emissions.”

As a report by economic consultancy NERA and researchers from Imperial College London has already shown, there are other ways to save bill payers money, while encouraging a low carbon future. Their analysis published in early 2016 found that households and businesses could save £2bn if the government considered the whole system cost of electricity generation and supply when designing its competitions for support under its Contracts for Difference (CfD) scheme.

2016, redux

Without the Carbon Price Support, the UK wouldn’t have managed to send carbon emissions back to 19th century levels.

So if 2016 was played out one more time but with no Carbon Price Support:

  • Coal generation would have increased by 102% (28 terawatt-hours) to 56 TWh
  • Gas generation would have decreased by 21% (-27 TWh) to 101 TWh
  • Carbon emissions would have risen by 21% (16 million tonnes of carbon dioxide) to 92MT CO2
  • The carbon intensity of the grid would have increased by 20% from 290 gCO2/kWh to 349 gCO2/kWh

And if 2016 had seen a doubling of the CPS to £36/tCO2:

  • Coal generation would have decreased by 47% (-12.9 TWh) to 14.7 TWh
  • Gas generation would have increased by 9% (11.8 TWh) to 139.5 TWh
  • Carbon emissions would have decreased by 10% (7.3 MT CO2) to 68.6 MT CO2
  • The carbon intensity of the grid would have decreased by 9% from 290 gCO2/kWh to 263 gCO2/kWh

The two scenarios presented above only modelled the impact of no or a higher Carbon Price Support on nuclear, coal and gas power supply. In the real-world, changes to the Carbon Price Support would also impact on energy technologies that operate under the Renewables Obligation (RO) such as two of Drax’s three biomass units and much of the country’s other renewable capacity. CPS changes would also likely impact imports and storage.

While no analysis is perfect this clearly illustrates the significantly negative impact that scrapping or reducing the Carbon Price Support would have on the UK’s decarbonisation agenda. It also highlights the benefits that the government’s decision to remain committed to carbon pricing will deliver.

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.