Tag: energy policy

Why we need the whole country on the same frequency

23 June 2017

Power generation
Electricity frequency

The modern world sits on a volatile, fizzing web of electricity. In 2015 the UK consumed roughly 303 terawatt hours (TWh) of electricity, according to government statistics. That’s an awful lot of power humming around and, in this country, we take it for granted that electricity is controlled. This means the power supply coming into your home or place of work is reliable and won’t trip your fuse box. In short, it means your mobile phone will keep on charging and your washing machine will keep on spinning.

But generating and circulating electricity at safe, usable levels is not an easy task. One of the most overlooked aspects of doing this is electrical frequency – and how it’s regulated.

What is electrical frequency?

To understand the importance of frequency, we need to understand a couple of important things about power generation. Generators work by converting the kinetic energy of a spinning turbine into electrical energy. In a steam-driven generator (like those at Drax Power Station), high pressure steam turns a turbine, which turns a rotor mounted inside a stator. Copper wire is wound around the rotor energised with electricity, this turns it into an electromagnet with a north and south pole.

The stator is made up of large, heavy duty copper bars which enclose the rotor. As the rotor turns, its magnetic field passes through the copper bars and induces an electric current which is sent out onto the transmission system.

As the magnetic field has a north and south pole, the copper bars experience a change in direction of the magnetic field each time the rotor turns. This makes the electric current change direction twice per revolution and is called an alternating current (AC). There are in fact three sets of copper bars in the stator, producing three electrical outputs or phases termed red, yellow and blue.

Electrical frequency is the measure of the rate of that oscillation and is measured in the number of changes per second – also called hertz (Hz). A generator running at 3,000 rpm, with two magnetic poles, produces electricity at a frequency of 50Hz.

Turbine Hall at Drax Power Station

Why is this important? 

Maintaining a consistent electrical frequency is important because multiple frequencies cannot operate alongside each other without damaging equipment. This has serious implications when providing electricity at a national scale.

The exact figure is less important than the need to keep frequency stable across all connected systems. In Great Britain, the grid frequency is 50Hz. In the US, it’s 60Hz. In Japan, the western half of the country runs at 60Hz, and the eastern half of the country runs at 50Hz – a string of power stations across the middle of the country steps up and down the frequency of the electricity as it flows between the two grids.

Sticking to one national frequency is a team effort. Every generator in England, Scotland and Wales connected to the high voltage transmission system is synchronised to every other generator.

When the output of any of the three phases – the red, yellow or blue – is at a peak, the output from all other phases of the same colour on every other generating unit in Great Britain is also at a peak. They are all locked together – synchronised – to form a single homogenous supply which provides stability and guaranteed quality.

How is frequency managed?

The problem is, frequency can be difficult to control – if the exact amount of electricity being used is not matched by generation it can affect the frequency of the electricity on the grid.

For example, if there’s more demand for electricity than there is supply, frequency will fall. If there is too much supply, frequency will rise. To make matters more delicate, there’s a very slim margin of error. In Great Britain, anything just 1% above or below the standard 50Hz risks damaging equipment and infrastructure. (See how far the country’s frequency is currently deviating from 50 Hz.)

Managing electrical frequency falls to a country’s high voltage transmission system operator (the National Grid in the UK). The Grid can instruct power generators like Drax to make their generating units automatically respond to changes in frequency. If the frequency rises, the turbine reduces its steam flow. If it falls it will increase, changing the electrical output – a change that needs to happen in seconds.

In the case of generating units at Drax Power Station, the response starts less than a second from the initial frequency deviation. The inertial forces in a spinning generator help slow the rate of frequency change, acting like dampers on car suspension, which minimises large frequency swings.

Frequency on a fast-changing system

Not all power generation technologies are suited for providing high quality frequency response roles and as the UK transitions to a lower-carbon economy, ancillary services such as stabilisation of frequency are becoming more important.

Neither solar nor wind can be as easily controlled. It’s possible to regulate wind output down or hold back wind turbines to enable upward frequency response when there is sufficient wind.

Similarly, solar panels can be switched on and off to simulate frequency response. As solar farms are so widely dispersed and tend to be embedded – meaning they operate outside of the national system, it is not as easy for National Grid to instruct and monitor them. Both wind and solar have no inertia so the all-important damping effect is missing too. Using these intermittent or weather-dependent power generation technologies to help manage frequency can be expensive compared to thermal power stations.

Nor are the current fleet of nuclear reactors flexible – nuclear reactors in Great Britain were designed to run continuously at high loads (known as a baseload power). Although they cannot deliver frequency response services, the country’s nuclear power stations do provide inertia.

UK plug on blue wall

Twenty times faster

Thermal power generation technologies such as renewable biomass or fossil fuels such as coal and gas are ideal for frequency response services at scale, because they can be easily dialled up or down. As both the fuel supply to their boilers and steam within their turbines can be regulated, the 645 MW thermal power units at Drax have the capability to respond to the grid’s needs in as little as half a second or less, complete their change in output in under one second and maintain their response for many minutes or even hours.

Before the introduction of high volumes of wind and solar generation almost all generators (excluding nuclear) running on the system could provide frequency response. As these generators are increasingly replaced by intermittent technologies, the system operator must look for new services to maintain system stability.

An example is National Grid’s recent Enhanced Frequency Response tender, which asked for a solution that can deliver frequency stabilisation in under a second – 20 times faster than the Primary Response provided by existing thermal power stations. Drax was the only participating thermal power station, however all contracts were all won by battery storage projects.

Frequency future

Given the decline in fossil fuel generation and uncertainty around our power makeup in future decades, National Grid is consulting on how best to source services such as frequency response. The ideal scenario for National Grid is one where services can be increasingly sourced from reliable, flexible and affordable forms of low carbon generation or demand response.

The next generation of nuclear power stations, as with some already operating in France, can provide frequency response services. However the first of the new crop, Hinkley C, is around a decade away from being operational. Likewise, solar or wind coupled with battery, molten salt or flywheel storage will provide an increasing level of flexibility in the decades ahead as storage costs come down.

Thanks to power generation at Drax with compressed wood pellets, a form of sustainable biomass, Britain has already begun moving into an era where lower carbon frequency response can begin to form the foundation of a more reliable and cleaner system.

This story is part of a series on the lesser-known electricity markets within the areas of balancing services, system support services and ancillary services. Read more about black start, system inertia, reserve power and reactive power.  View a summary at The great balancing act: what it takes to keep the power grid stable and find out what lies ahead by reading Balancing for the renewable future and Maintaining electricity grid stability during rapid decarbonisation.

How many homes can we power with renewables?

25 May 2017

Power generation
Terraced houses at night time on portland dorset

More of Britain’s electricity is coming from renewables than ever before. New offshore wind farms, solar capacity hitting double figures and the reliability of biomass are having a marked effect on the country’s power.

Our electricity make up is more diverse than ever. More than this, it is cleaner. During the first three months of 2017, emissions from power generation were 10% lower than the same period last year and 33% lower than the first quarter of 2015.

And while this is a huge and necessary step in the UK’s efforts towards slowing global warming, it would mean little if renewables weren’t also keeping our lights on. That’s exactly what they are doing – powering businesses, industries and homes across the country. But how many, exactly?

The scale of renewables

In 2015 the total electricity consumption of the UK was 303 TWh. To put that into perspective, that’s roughly enough power to boil 121.1 billion kettles. A quarter of the 360 TWh of electricity generated that year  came from renewables – 84 TWh – a massive 29% increase over 2014. Of that figure, Drax’s biomass units contributed 11.5 TWh, approximately 3% of that year’s total power generation.

So, renewables are big, but how big?

Panoramic photo of modern house with outdoor and indoor lighting, at night

According to the 2011 Census there are 26.4 million households in the UK. Ofgem, the energy regulator, says the average UK household uses roughly 3.1 MWh of electricity a year (the average US household uses approximately 10.8 MWh).

If we were to hypothesise that all the renewable power generated in 2015 had been consumed by UK households, there would be enough to power every single one. And there’d be enough left over to power 600,000 more.

Using just the power generated thanks to sustainably sourced compressed wood pellets at Drax Power Station would be enough to satisfy the equivalent of 4.1 million homes – nearly twice the number of households in Scotland or 800,000 more homes than in the whole of London. 15% of all UK homes could have been powered by just half that one station in Selby, North Yorkshire.

Finding the right mix for the future

Electricity is used to power more than just homes. It powers businesses, transport and infrastructure – almost all parts of our lives are fuelled by electricity. While there may be the hypothetical equivalent to power every single household in the UK with renewables (with room to spare), the reality is there is a far larger nationwide demand that needs to be fulfilled. And this means we can’t rely on renewables alone. Instead, what’s required is an energy mix that also includes other low carbon sources of electricity – backed up by a new fleet of gas power stations and storage that can respond rapidly to changes in demand.

While we’re not yet in a position where we can power all homes all the time using renewables, that day could well be coming. A new report from the International Renewable Energy Agency (IREA) suggests a mix of renewable technologies including biomass and bioenergy with carbon capture and storage (BECCS) could meet the majority of global energy demand across all sectors of the world economy by 2050 – while helping to keep the rise in global temperatures to under two degrees celsius above 1990 levels.

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.

Sustainability, certified

24 March 2017

Sustainable bioenergy
Drax Morehouse woodchip truck

Of all the changes to Drax Power Station over the last decade, perhaps the biggest is one you can’t see. Since converting three of its six generating units from coal to run primarily on compressed wood pellets, Drax has reduced those units’ greenhouse gas (GHG) emissions by over 80%.

And while this is a huge improvement, it would mean nothing if the biomass with which those reductions are achieved isn’t sustainably sourced.

For this reason, Drax works with internationally-recognised certification programmes that ensure suppliers manage their forests according to environmental, social and economic criteria.

Thanks to these certification programmes, Drax can be confident it is not only reducing GHG emissions, but supporting responsible forestry from wherever wood fibre is sourced.

Sustainability certifications

The compressed wood pellets used at Drax Power Station come from various locations around the world, so Drax relies on a number of different forest certification programmes, the three main ones being the Sustainable Forest Initiative (SFI), Forest Stewardship Council® (FSC®)1 and the Programme for the Endorsement of Forest Certification (PEFC).

The programmes share a common goal of demonstrating responsible forest management, but adoption rates vary by region. European landowners and regulators are most familiar with the FSC and national PEFC standards, while North American landowners generally prefer SFI and American Tree Farm System (also members of the PEFC family). In instances in which Drax sources wood pellets carrying these certifications, or in instances in which Drax purchase pellets sourced from certified forests, these certifications offer an additional degree of assurance that the pellets are sustainable.

Over 50% of the pellets used at Drax Power Station come from the southern USA, where SFI and American Tree Farm System are the most widely implemented certification programmes. Overall adoption levels in this region are relatively modest. However, the SFI offers an additional level of certification that can be implemented by wood-procuring entities, such as sawmills, pulp mills and pellet mills.

This programme is referred to as SFI Fiber Sourcing, and to obtain it, participants must demonstrate that the raw material in their supply chains come from legal and responsible sources. These sources may or may not include certified forests. The programme also includes requirements related to biodiversity, water quality, landowner outreach and use of forest management and harvesting professionals. Together, these certification systems have long contributed to the improvement of forest management practices in a region that provides Drax with a significant proportion of its pellets.

And since the SFI and ATFS programmes are endorsed by PEFC, North American suppliers have a pathway for their region’s sustainable forest management practices to be recognised by European stakeholders.

These certification programmes have been in use for many years. But with recent growth in the market for wood pellets, a new certification system has emerged to deal specifically with woody biomass.

Trees locked up in a bundle

New kid on the block

The Sustainable Biomass Program (SBP) was set up in 2013 as a certification system to provide assurance that woody biomass is sourced from legal and sustainable sources. But rather than replacing any previous forest certification programmes, it builds on them.

For example, SBP recognises the evidence of sustainable forest management practices gathered under these other programmes. However, the PEFC, SFI and FSC programmes do not include requirements for reporting GHG emissions, a critical gap for biomass generators as they are obligated to report these emissions to European regulators. SBP fills this gap by creating a framework for suppliers to report their emissions to the generators that purchase their pellets.

When a new entity, such as a wood pellet manufacturer, first seeks certification under SBP, that entity is required to assess its supply base.

Feedstock which has already been certified by another established certification programme (SFI, FSC®, PEFC or PEFC approved schemes) is considered SBP-compliant.

All other feedstock must be evaluated against SBP criteria, and the wood pellet manufacturer must carry out a risk assessment to identify the risk of compliance against each of the 38 SBP indicators.

If during the process a specific risk is identified, for example to the forest ecosystem, the wood pellet manufacturer must put in place mitigation measures to manage the risk, such that it can be considered to be effectively controlled or excluded.

These assessments are audited by independent, third party certification bodies and scrutinised by an independent technical committee.

In conducting the risk assessment, the wood pellet manufacturer must consult with a range of stakeholders and provide a public summary of the assessment for transparency purposes.

Sustainable energy for the UK

Counting major energy companies including DONG Energy, E.ON and Drax as members, the SBP has quickly become an authoritative voice in the industry. At the end of 2016, the SBP had 74 certificate holders across 14 countries – including Drax’s pellet manufacturing arm, Drax Biomass, in Mississippi and Louisiana.

It’s a positive step towards providing the right level of certification for woody biomass, and together with the existing forestry certifications it provides Drax with the assurance that it is powering the UK using biomass from legal and sustainable sources.

Like the fast-reducing carbon dioxide emissions of Britain’s power generation sector, it’s a change you can’t see, but one that is making a big difference.

Read the Drax principles for sustainable sourcing.

1 Drax Power Ltd FSC License Code: FSC® – C119787

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.

4 firsts for Britain’s power system

9 February 2017

Power generation
fishing boat and wind turbines

It’s no secret 2016 was a year of change. But beyond the high stakes political changes were events that indicate a shift of a similar size (if far less controversial) – the move to a decarbonised power network.

In the last three months of 2016 this change was characterised by four ‘firsts’ in the history of Britain’s power network. Each one signals a continuing trend that could offer a sign of what’s to come in the future.

The findings come from Electric Insights, a quarterly report from researchers at Imperial College London, commissioned by Drax. It tracks the rises and falls of the power generation system in England, Scotland and Wales, plus its environmental impact.

4_common_renewable_myths_full_size

1. Wind power reached record output but was down overall

One of the most interesting events was the way the wind blew – both a lot and not very much. 2016 was the first ever year that wind generated more power than coal. And a large part of that was thanks to the weather.

On the 23rd December, Storm Barbara hit the UK, bringing strong winds of up to 90 miles per hour. As a result, wind output produced more than 10GW for the first time ever, beating the previous record of 9.4GW set in 2014. At its peak, wind power met 37% of British demand, generating enough electricity for 15 million people – or everyone (and everything) north of Nottingham.

But despite these peaks, over the full quarter wind output was in fact 7% lower than the same time period in 2015. So while it was a quarter that showed how important a part of our power make up wind is right now and will be in the future, it also showed how much it depends on the weather.

The cliffs at Dover, UK

2. Britain exported more power to France than it imported

For the first time in six years Britain exported more electricity to France than it imported. Electricity flows between the two countries via an undersea interconnector called the Interconnexion France-Angleterre – and normally we accept more from the French nuclear generators and its other power sources than we send back. That changed at the end of 2016.

More than a dozen of France’s nuclear power stations where turned off after safety checks found a flaw in their design. While urgent maintenance took place during the last few months of 2016, British electricity generators exported power to meet French demand – taking advantage of higher-than-usual electricity prices on the other side of the English Channel. In fact, Britain exported more in one week in November than over the whole of 2014 and 2015 combined.

Coal spinner

3. Carbon emissions were at a 60-year low

Low carbon energy sources keep on rising as a proportion of the UK’s total output and in the last quarter of 2016 this meant carbon emissions fell to their lowest autumn level for 60 years. Overall in 2016, coal generation fell by 61% as a mixture of low gas prices and the Carbon Price Floor continued to force it off the system. Low carbon power sources grew to fill the gap, contributing an average of 40% of the UK’s power, while gas generation was up by more than 50%.

More than that, the quarter also saw another record – Britain’s cleanest Christmas in history. Up to 81% of Britain’s power was generated by low carbon sources, and the share of nuclear, biomass, hydro, wind and solar did not fall below 60% during the three days between Christmas Eve and Boxing Day.

8th November 2016 electricity peaked at more than £1500 per MWh

4. Electricity prices hit a new peak, but also dipped below zero

Electricity prices reached their highest in a decade: £1,528 per MWh. But they didn’t stay there – for nineteen hours during the quarter, they also dropped below zero. Negative energy prices occur when there is low demand and power being generated from inflexible sources (for example the current British nuclear fleet, plus wind and solar), exceeds the amount needed. When this happens, generators have to pay to offload the excess electricity, which means Elexon – the body that handles payments in the balancing market – is essentially managing a market that’s paying below zero for electricity.

These extremes raise the question of whether such price volatility is the new normal. As more renewable energy comes onto the network, its sensitivity to the elements increases, which in turn can increase volatility. The answer is: possibly.

A man at Drax Power Station looking at a biomass storage dome

What does this mean for the future?

The number of firsts in Britain’s power system signifies the scale of change it’s currently seeing. With the end date for coal coming ever closer, the country is increasingly realising the importance of exploring – and using – lower-carbon fuels to generate its electricity. Given the pace of change we’ve already seen, by the time we reach the last few months of 2017, Britain may well be welcoming in another new range of electricity firsts.

Explore the data in detail by visiting www.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.

Your neighbourhood electricity network

31 January 2017

Electrification
Engineers from Electricity North West fixing electricity wires.

Britain’s electricity network is a lot like its roads. For long distance, high-speed journeys, the road network has motorways – the electricity network’s equivalent is the National Grid, which transfers power across the country at extremely high voltages (between 400,000-132,000 volts) and high speeds.

For shorter journeys at progressively lower speeds, the traffic network has ‘A’ and ‘B’ roads. These are the regional distribution networks.

These regional distribution networks take power at 132,000 volts and transform it down in stages to 230 volts and make the link from the National Grid to local distribution systems that deliver electricity to homes and businesses.

And while these A and B roads of electricity may be one of the most important parts of getting electricity from power station to plug, very few people spare them any thought.

Electricity in the north west

“When the government first privatised the electricity network in 1989, it set up different distribution regions to provide national coverage through a series of similarly-sized regions,” says Pete Emery, Senior Director of Electricity North West.

Today each part of the UK is served by one of 14 different regional networks and in the north west, across the Pennines from where Drax Power Station operates in North Yorkshire, that’s the job of Electricity North West. It was formed in 1995 and today delivers around 23 terawatts of power to 2.2 million homes and 200,000 business every year.

It does that using a vast network of more than 13,000 km of overhead cables, 44,000 km of underground cables (making it the second most underground electricity network in the UK behind London) and more than 34,000 transformers, which work to convert the electricity from transmission voltage to one that can be used in UK homes.

The scale of infrastructure needed to create these regional networks mean that each one is a ‘natural monopoly’. In this case, it’s a monopoly that benefits customers.

Top of houses buildings in Manchester, England, Europe.

A ‘natural monopoly’

“A natural monopoly is when the cost of duplicating the assets needed to provide the service outweighs the benefits of efficiency that having competition would provide,” explains Emery. “So it is in the public interest to have only one provider.”

For decades, each regional distribution network has operated the same way, delivering power consistently to UK homes. But as the country moves into the future of cleaner, more sustainable energy, these grids are changing rapidly.

The potential proliferation of battery technologies, and the increasing variation of power sources and their demands on the grid mean changes are in store for distributors like Electricity North West.

One such factor already having an effect is embedded generation. Across the country there are sources of electricity generation that aren’t connected to regional distribution networks – for example, private solar panels on domestic roofs, wind turbines on private land, or small-scale power stations connected to a single, private distribution network. And when there is excess electricity generated from these sources, it can be sold back to electricity suppliers. In the north west, this embedded generation is fed back into Emery’s network.

“In our region alone, we have 2,200 MW of embedded generation – more than half the capacity of Drax Power Station – which means we already manage and control the power this input brings to the electricity system,” says Emery. “They are invisible to National Grid. This is a radical change and it’s happening now.”

Regardless of what’s to come, what’s certain is there’ll be traffic on the A roads of electricity.

A positive negative

18 January 2017

Carbon capture
Tubes running in the direction of the setting sun. Pipeline transportation is most common way of transporting goods such as Oil, natural gas or water on long distances.

This story was updated in June 2018 following the announcement of Drax’s pilot BECCS project.

Is there a way to generate electricity not only with no emissions, but with negative emissions?

It’s an idea that, after decades of being reliant on coal had seemed almost impossible. But as Drax has shown by announcing a pilot of the first bioenergy carbon capture storage (BECCS) project of its kind in Europe, it might not be impossible for much longer.

A few years on from the historic Paris Agreement – which sets a target of keeping global temperature rise below two degrees Celsius – innovative solutions for reducing emissions are critical. Among these, few are more promising than BECCS.

It sounds like a straightforward solution – capture carbon emissions and lock them up hundreds of metres underground or turn the carbon into useful products – but the result could be game-changing: generating electricity with negative emissions.

Capturing carbon

Carbon capture and storage (CCS) technology works by trapping the carbon dioxide (CO2) emitted after a fuel source has been used and moving it to safe storage – often in depleted oil and gas reservoirs underground.

There are a number of CCS technologies available but one of the simplest is oxyfuel combustion. Fuel such as coal, gas or biomass, is burnt in a high oxygen environment and CO2 – rather than carbon (C) or carbon monoxide (CO) – is produced. Other impurities are removed and the resulting pure CO2 is compressed to form a liquid. This CO2 can then be transported via pipeline to its designated storage space, normally hundreds of metres underground.

The UK is well-placed to benefit from the technology thanks to the North Sea – which has enough space to store the EU’s carbon emissions for the next 100 years.

It’s a technology that can drastically reduce the emissions from fossil fuel use, but how can it be used to produce negative emissions?

Two technologies, working as one

Biomass, such as sustainably sourced compressed wood pellets, is a renewable fuel – the CO2 captured as part of its life in the forest is equal to the emissions it releases when used to generate electricity. When coupled with CCS, the overall process of biomass electricity generation removes more CO2 from the atmosphere than it releases.

A report published by the Energy Technology Institute (ETI) looking at the UK has suggested that by the 2050s BECCS could deliver roughly 55 million tonnes of net negative emissions a year – approximately half the nation’s emissions target.

It’s not the only body heralding it as a necessary step for the future. The Intergovernmental Panel on Climate Change (IPCC), stated in a 2014 report that keeping global warming below two degrees Celsius would be difficult if BECCS had limited deployment.

Support is widespread, but for it to lead to a practical future, BECCS needs suitable support and investment.

Morehouse BioEnergy pellet plant

Mills such as Morehouse BioEnergy manufacture compressed wood pellets – a sustainably-sourced fuel for BECCS power plants of the future.

Positive support for negative emissions

There are only a handful of CCS projects in operation or under construction across the world and many simply re-use rather than capture the CO2. Part of the reason is cost. It’s estimated that optimal CCS technology can cost about as much as the power station itself to install, and running it can consume up to 20% of a station’s power output. This means more fuel is needed to produce the same amount of power compared to a conventional power plant of similar efficiency.

Without government support, it remains a prohibitively expensive solution for many power generators. With government support in the form of multi-decade contracts, large CCS or BECCS plants could leverage economies of scale. They could deliver energy companies and their shareholders a return on the investments in the long-term.

Drax research and development

Past plans by Drax could have put the company on a timeline towards becoming the world’s first large scale negative emitter of CO2. It would have achieved it firstly with the construction of a CCS power station at its Selby, North Yorkshire site.

The 428 MW White Rose power station was to be fuelled by a mixture of coal and biomass and once in operation, could have paved the way for similar facilities elsewhere as carbon capture technology improved and costs came down, but unfortunately the project never went ahead.

There are some positive signs that carbon capture technologies are developing around the world. The first ‘clean coal’ power station became operational in the US earlier this month – and a second CCS plant is on the way. A UK-backed carbon capture and use (CCU) project in India recently opened at a chemicals factory, involving the capture of emissions for use in the manufacturing process.

Back in the UK, where the government outlined plans to end coal-fired power generation by 2025, carbon capture power stations must become financially competitive if they are to become a major part of the country’s low carbon future. But if the world is to achieve the targets agreed in Paris and pursue a cleaner future, negative emissions are a must, and BECCS remains a leading technology to help achieve it.