Tag: technology

Carbon markets will be essential in reaching net zero – we must ensure they support high standards

9 November 2022

Carbon capture

Angela Hepworth, Commercial Director, Drax

In brief:

  • The voluntary carbon market will be essential in deploying engineered carbon removals technologies like Bioenergy with carbon capture and storage (BECCS), and direct air carbon capture and storage (DACS) at scale.
  • The Integrity Council for the Voluntary Carbon Market is developing a set of Core Carbon Principles (CCPs).
  • Drax support proposed principals if they’re applied in ways appropriate for engineered carbon removals.
  • Standards around additionality and the permeance of carbon removals may apply very differently to nature-based and engineered removals, something that needs to be addressed explicitly.

There’s growing recognition, in governments and environmental organisations, of the urgent need to develop high-integrity engineered carbon removals at scale if the world has any chance of meeting our collective Paris-aligned climate goals.

Bioenergy with carbon capture and storage (BECCS), and direct air carbon capture and storage (DACS) are two technologies on the cusp of deployment at scale that can remove carbon from the atmosphere and store it permanently and safely. The technology is proven, developers are bringing forward projects, and the most forward-thinking companies are actively seeking to buy removal credits from BECCS and DACS developers.

Yet there’s a risk that the frameworks being developed in the voluntary carbon market could stifle rather than support the development of engineered carbon removals.

Drax is a world-leader in the deployment of bioenergy solutions. Our goal is to produce 12 million tonnes of high-integrity, permanent CO2 removals by 2030 from its BECCS projects in the U.K. and the U.S. We support the development of rigorous standards for CO2 removals that give purchasers confidence in the integrity of the CO2 removals they’re buying. Such standards are also important in providing a clear framework for project developers to work to.

However, the market and its standards have largely developed around carbon reduction and avoidance credits, rather than removals. To create a market that can enable engineered carbon removals at scale, re-thinking is needed to create standards that are fit for purpose to tackle the climate emergency.

Core Carbon Principles

The Integrity Council for the Voluntary Carbon Market is in the process of developing a set of Core Carbon Principles (CCPs) and Assessment Framework (AF) intended to set new threshold standards for high-quality carbon credits.

At Drax, we welcome and support the principals proposed by the Integrity Council. However, it’s crucial they’re applied in ways that are appropriate for engineered carbon removals, and support rather than prevent their development.

Many CCPs are directly applicable to engineered carbon removals and can offer important standards for projects developing removals technologies. Among the most important principals include those stating:

  • Removals must be robustly quantified, with appropriate conservatism in any assumptions made.
  • Key information must be provided in the public domain to enable appropriate scrutiny of the carbon removal activity, while safeguarding commercially sensitive information.
  • Removal credits should be subject to robust, independent third-party validation and verification.
  • Credits should be held in a registry which deals appropriately with removal credits.
  • Registries must be subject to appropriate governance, to ensure their integrity without becoming disproportionately bureaucratic or burdensome.
  • Removals must adhere to high standards of sustainability, taking account of impacts on nature, the climate and society.
  • There should be no double counting of carbon removals between corporates, or between countries. Bearing in mind that both corporates and countries may count the same removals in parallel, and that the Article 6 mechanism means countries can decide whether trades between corporates should or shouldn’t trigger corresponding adjustments to countries’ carbon inventories.

However, as pioneers in the field, we believe that two of the Core Carbon Principles need to be adapted to the specific characteristics of engineered carbon removals.

Supporting additionality and development incentives

The CCPs state: “The greenhouse gas (GHG) emission reductions or removals from the mitigation activity shall be additional, i.e., they would not have occurred in the absence of the incentive created by carbon credit revenues.”

Engineered carbon removal credits such as BECCS and DACS are by their nature additional. They are developed for the specific purpose of removing CO2 from the atmosphere and putting it back in the geosphere. They also rely on revenue from carbon markets – largely the voluntary market at present, but potentially compliance markets such as the U.K. and E.U. ETS in the future.

However, most early projects are likely to have some form of Government support (e.g., 45Q in the U.S., or Contracts for Difference in the U.K.) from outside carbon credit revenues. But that support isn’t intended to be sufficient on its own for their deployment – project developers will be expected to sell credits in compliance or voluntary markets.

Engineered carbon removals have high up-front capital costs, and it’s clear that revenue from voluntary or compliance markets will be essential to make them viable.

Additionality assessments should be risk-based. If it’s clear that a technology-type is additional, a technology-level assessment should be sufficient. This should be supplemented with full transparency on any government support provided to projects.

Compensating against non-permanent storage

On the topic of permeance that CCPs state: “The GHG emission reductions or removals from the mitigation activity shall be permanent, or if they have a risk of reversal, any reversals shall be fully compensated.”  A key benefit of engineered carbon removals with geological storage is that they effectively provide permanent carbon removal. Any risk of reversal over tens of thousands of years is extremely small.

The risk of reversal for nature-based credits, by contrast, is much greater. Schemes for managing reversal risk in the voluntary carbon market that have been developed for nature-based credits, are not necessarily appropriate for engineered removals.

Requirements for project developers to set aside a significant proportion of credits generated in a buffer pool, potentially as much as 10%, are disproportionate to the real risk of reversal from a well-manged geological store. They also fail to take account of the stringent regulatory requirements for geological storage that already exist or are being put in place.

Any ongoing requirements for monitoring should be consistent with existing regulatory requirements placed on storage owners and operators. Similarly, where jurisdictions have robust regulatory arrangements for dealing with CO2 storage risk, which place liabilities on storage owners, operators, or governments, the arrangements in the voluntary carbon market should mirror these arrangements rather than cutting across them, and no additional liabilities should be put on project developers.

At Drax, we believe the CCPs provide a suitable framework to ensure the integrity of engineered carbon removals. If applied pragmatically, they can give purchasers of engineered carbon removal credits confidence in the integrity of the product they’re buying and provide a clear framework for project developers. They can ensure that standards support, rather than stifle the development of high integrity carbon removal projects such as BECCS and DACS, which are essential to achieving our global climate goals.

9 of the biggest TV moments in UK electricity history

1 August 2022

Power generation

It’s 1990 and Chris Waddle, England midfielder, steps up to the penalty spot. The 60,000 people in Turin’s Stadio delle Alpi watching him and the fate of England football go silent.

He takes a breath and fires a shot at Bodo Illgner, the German goalkeeper. It careers over the crossbar and misses – England are out of the World Cup. The now famous image of Paul Gascoigne crying into his shirt is beamed across millions of UK television screens.

There’s a shuffling on the sofas in front of those TVs as the population gets up to make a cup of tea, get a drink or turn on the oven. Millions of kettles, lights and fridges are powered up as the country collectively despairs. The demand for electricity across the country soars.
kettle boilingThis is what’s called a ‘TV pickup’ – the moment during a popular television event when there’s a break and viewers unwittingly cause a huge surge of demand from the National Grid.

It’s these moments that have caused some of the biggest spikes in UK electricity demand. Here we look at what’s caused them:

One:

What? Football World Cup Semi Final: England v West Germany
When? Wednesday, 4 July 1990
Electricity demand: 2,800MW – equivalent to 1,120,000 kettles (based on 1MW = 400 kettles), or 4.3 Drax-sized generation units (there are six 645MW units at Drax)

After that fateful penalty miss the population made for the kitchen. The match was watched by an estimated 26 million people in the UK, and when full time was called they caused a 2,800MW surge in electricity demand.

Two:

What? The Thorn Birds
When? 22 January 1984
Electricity demand: 2,600MW – 1,040,000 kettles – 4 Drax units

A sleeper hit, The Thorn Birds was a one-off American mini-series about a fictional sheep station in the Australian outback. Based on the novel of the same name, it was broadcast in the UK following building up a huge following in the US when it was aired in 1983. By the time it arrived on UK shores there was clearly enough of that excitement to create a surge of electricity demand – one of the largest in UK TV history.

Three:

What? Football World Cup Quarter Final: England v Brazil
When? Friday, 21 June 2002
Electricity demand: 2,570MW – 1,028,000 kettles – 4 Drax units

Broadcast early on a Wednesday morning in the UK due to time differences with South Korea, where the game was played, the match saw England put up a solid fight against overall tournament winners Brazil. A goal from Michael Owen provided early hope and at half time TV viewers left their screens to cause a huge 2,570MW spike in demand. By the time the game had reached its conclusion, Brazil had won thanks to a chipped Ronaldinho free kick that fooled England keeper David Seaman and those viewers who had lasted the duration caused a slightly smaller 2,300MW surge.

Sad couple watching football match on television at home.

Four:

What? Eastenders: Lisa admits shooting Phil
When? Thursday, 5 April 2001
Electricity demand: 2,290MW – 916,000 kettles – 3.5 Drax units

In one of the most dramatic plot developments in UK TV history, Lisa Shaw, played by actress Lucy Benjamin, admitted to shooting her former boyfriend, Phil Mitchell. An estimated 22 million viewers turned on to see the dramatic reveal. When it was all over they caused a surge of 2,290MW, more than five times the normal pickup of 400MW seen at the end of an average Eastenders episode.

Five:

What? The Darling Buds of May
When? Sunday, 12 May 1991
Electricity demand: 2,200MW – 880,000 kettles – 3.4 Drax units

One of the more wholesome entries to the list, this British comedy drama racked up a huge following during its 20-episode run from 1991 to 1993. The peak was early in the first season, when the third ever episode saw the Larkin family take an unhappy holiday to Brittany. The family’s escapades drew a large audience and prompted a surge equivalent to 880,000 kettles being switched on at the same time.

Six:

What? Rugby World Cup Final: England v Australia
When? Saturday, 22 November 2003
Electricity demand: 2,110MW – 844,000 kettles – 3.3 Drax units

A unique sporting entry to the list as England ended as winners. More than 12 million people watched England beat Australia, with the largest electricity demand coming at half time and not at full time, when audiences were presumably still celebrating Jonny Wilkinson’s last minute drop goal.

Seven:

What? European Football Championship 2020 final: England vs Italy
When? Sunday, 11 July 2021
Electricity demand: 1,800MW – 720,000 kettles – 2.8 Drax units

The most recent heartbreaker for England fans, the match came as COVID-19 restrictions were only beginning to lift around the UK. The team, led by Gareth Southgate, conquered old foes Germany on their way to a final in Wembley, only to lose to Italy on penalties.

The sense of disappointment was almost palpable in the energy demand, peaking at 1,800MW at half-time, when England went into the changing rooms one-nil up. Demand then surged again to 1,200MW at the end of the 90-minute stalemate, followed by a deflated 500MW at the end of the game. Had things gone differently, National Grid ESO was preparing for a peak of 2,000MW.

Eight:

What? The Royal Wedding – Prince William and Kate
When? Friday, 29 April 2011
Electricity demand: 1,600MW – 640,000 kettles – 2.5 Drax units

The biggest and most celebrated Royal Wedding in a generation, the marriage of Prince William and Kate Middleton attracted an audience of 24 million in the UK alone. Energy demand peaked at 1,600MW when the bride’s carriage procession returned to Buckingham Palace. This is the largest TV pickup in recent years, which hints at how changing viewer habits, on demand watching and smart TVs are changing the need for power and making TV pickups a rarer occurrence.

Nine:

What? Clap for carers
When? Thursday, 16 April 2020
Electricity demand: 950MW – 320,000 kettles – 1.5 Drax units

COVID-19 and subsequent lockdowns had several interesting effects on the UK’s energy system. One feature was a return in regular demand spikes, with Thursday evenings’ Clap for Carers events prompting notable surges.

The gestures, held at 8pm on Thursdays between 26 March and 28 May 2020, saw millions across the UK stand outside their homes and clap in appreciation of emergency services workers. As people went back inside to put on kettles and turn on TVs electricity demand spiked. The particularly cloudy evening of 16 April saw demand reach 950MW as more people reached for light switches.

 

How do we deal with TV pickups?

National grid electricty pylon silhouette at sunrise

Because the level of electricity needed to power the country can’t be stored, when there is a spike in demand it needs to be met quickly by a similar increase in real time generation.

To manage the supply and demand for events likely to cause electricity surges, the National Grid forecasts electricity need for large events like World Cups and major TV events.

The grid can then put contingency measures in place to manage the huge changes in demand in real time. It does this through a suite of tools called balancing mechanisms, which allows it to access sources of extra power in real-time.

The rise of more energy efficient home appliances and on-demand streaming means that the ‘shape’ of electricity demand has become flatter since the days when most of the country was tuned into the same must-see moments.

However, it’s still crucial for the grid to forecast periods of high demand, when it will keep the necessary power stations on reserve, ready to deliver additional electricity if needed.

If it wasn’t for this careful management of electricity by the grid and the power stations like Drax supplying it, that cup of tea next time England crash out of a major sporting event would not only be tainted with disappointment but cold, too.

Why and how is carbon dioxide transported?

11 April 2022

Carbon capture

What is carbon transportation?

Carbon transportation is the movement of carbon from one place to another. In nature, carbon moves through the carbon cycle. In industries like energy, however, carbon transportation refers to the physical transfer of carbon dioxide (CO2) emissions from the point of capture to the point of usage or storage.

Why does carbon need to be transported?

Anthropogenic (man-made) CO2 released in processes like power generation leads to the direct increase of CO2 in the atmosphere and contributes to global warming.

However, these emissions can be captured as part of carbon capture and storage (CCS). The CO2 is then transported for safe and permanent storage in geological formations deep underground.

Capturing and storing CO2 prevents it from entering the atmosphere and contributing to global warming. Processes that can deliver negative emissions – such as bioenergy with carbon capture and storage (BECCS) and direct air capture and storage (DACS) – aim to permanently remove CO2 from the atmosphere through CCS.

In CCS, carbon must be transported from the site where it’s captured to a site where it can be permanently stored. This means it needs to travel from a power station or factory to a geological formation like a saline aquifer or depleted oil and gas reservoirs.

As of September 2021, there were 27 operational CCS facilities around the world, with the combined capacity to capture around 40 million tonnes per annum (Mtpa) of CO2. It’s estimated that the UK alone has 70 billion tonnes of potential CO2 storage space in sandstone rock formations under the North Sea.

How is carbon transported?

CO2 can be transported via trucks or ships, but the most common and efficient method is by pipeline. Moving gases of any kind through pipelines is based on pressure. Gases travel from areas of high pressure to areas of low pressure. Compressing gas to a high pressure allows it to flow to other locations.

Gas pipelines are common all around the world, including those transporting CO2. In the US there are, for instance, more than 50 CO2 pipelines – covering around 6,500 km and transporting approximately 68 million tonnes of CO2 a year.

Gas takes up less volume when it’s compressed, and even less when it is liquefied, solidified, or hydrated. Therefore, before being transported, captured CO2 is often compressed and liquefied until it becomes a supercritical fluid.

In a supercritical state, CO2 has the density of a liquid but the viscosity (thickness) of a gas and is, therefore, easier to transport through pipelines. It’s also 50-80% less dense than water, with a viscosity that is 100 times lower than liquid.

This means it can be loaded onto ships in greater quantities and that there is less friction when it’s moving through pipes and, subsequently, into geological storage sites.

How safe is it to transport carbon?

It’s no riskier to transport CO2 via pipeline or ship than it is to transport oil and natural gas, and existing oil and natural gas pipelines can be repurposed to transport CO2.

To enable the safe use of CO2 pipelines, CCS projects must ensure captured CO2 complies with strict purity and temperature specifications, as well as making sure CO2 is dry and free from impurities that could impact pipelines’ operations.

Whilst there are a growing number of CCS transport systems around the world, CCS is still is a relatively new field but research is underway to identify best practises, materials and technologies to optimise the process. This includes research around potential risks and techniques for leak mitigation and remediation.

In the UK, the Health and Safety Executive regulates health, safety, and integrity issues for all natural gas pipelines, which are covered by legislation. The legislation ensures the safety of pipelines, pressure systems and offshore installations and can serve as a strong foundation for CO2 transport regulation.

Fast facts

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How biomass can enable a hydrogen economy

10 March 2022

Carbon capture

Key points:

  • Hydrogen as a fuel offers a carbon-free alternative for hard-to-abate sectors such as heavy road transport, domestic heating, and industries like steel and cement.
  • There are several methods of producing hydrogen, the most common being steam methane reforming, which can be a carbon-intensive process.
  • Biomass gasification with CCS is a form of bioenergy with carbon capture and storage (BECCS) that can produce hydrogen and negative emissions – removing CO2 permanently from the atmosphere.
  • The development of both BECCS and hydrogen technologies will determine how intrinsically connected the two are in a net zero future.

Reaching net zero means more than just transitioning to renewable and low carbon electricity generation. The whole UK economy must transform where its energy comes from to low-emissions sources. This includes ‘hard-to-abate’ industries like steel, cement, and heavy goods vehicles (HGVs), as well as areas such as domestic heating

One solution is hydrogen. The ultra-light element can be used as a fuel that when combusted in air produces only heat, water vapour, and nitrous oxide. As hydrogen is a carbon-free fuel, a so-called ‘hydrogen economy’ has the potential to decarbonise hard-to-abate sectors.

While hydrogen is a zero-carbon fuel its production methods can be carbon-intensive. For a hydrogen economy to operate within a net zero UK carbon-neutral means of producing it are needed at scale. And biomass, energy from organic material – with or without carbon capture and storage (in the case of BECCS)– could have a key role to play.

In January 2022, the UK government launched a £5 million Hydrogen BECCS Innovation Programme. It aims to develop technologies that can both produce hydrogen for hard-to-decarbonise sectors and removeCO2 from the atmosphere. The initiative highlights the connected role that biomass and hydrogen can have in supporting a net zero UK.

Producing hydrogen at scale

Hydrogen is the lightest and most abundant element in the universe. However, it rarely exists on its own. It’s more commonly found alongside oxygen in the familiar form of H2O. Because of its tendency to form tight bonds with other elements, pure streams of hydrogen must be manufactured rather than extracted from a well, like oil or natural gas.

As much as 70 million tonnes of hydrogen is produced each year around the world, mainly to make ammonia fertiliser and chemicals such as methanol, or to remove impurities during oil refining. Of that hydrogen, 96% is made from fossil fuels, primarily natural gas, through a process called steam methane reforming, of which hydrogen and CO2 are products. Without the use of carbon capture, utilisation, and storage (CCUS) technologies the CO2 is released into the atmosphere, where it acts as a greenhouse gas and contributes to climate change.

Another method of producing hydrogen is electrolysis. This process uses an electric current to break water down into hydrogen and oxygen molecules. Like charging an electric vehicle, this method is only low carbon if the electricity sources powering it are as well.

For electrolysis to support hydrogen production at scale depends on a net zero electricity grid built around renewable electricity sources such as wind, solar, hydro, and biomass.

However, bioenergy with carbon capture and storage (BECCS) offers another means of producing carbon-free renewable hydrogen, while also removing emissions from the atmosphere and storing it – permanently.

Producing hydrogen and negative emissions with biomass 

Biomass gasification is the process of subjecting biomass (or any organic matter) to high temperatures but with a limited amount of oxygen added that prevents complete combustion from occurring.

The process breaks the biomass down into a gaseous mixture known as syngas, which can be used as an alternative to methane-based natural gas in heating and electricity generation or used to make fuels. Through a water-gas shift reaction, the syngas can be converted into pure streams of CO2 and hydrogen.

Ordinarily, the hydrogen could be utilised while the CO2 is released. In a BECCS process, however, the CO2 is captured and stored safely and permanently. The result is negative emissions.

Here’s how it works: BECCS starts with biomass from sustainably managed forests. Wood that is not suitable for uses like furniture or construction – or wood chips and residues from these industries – is often considered waste. In some cases, it’s simply burnt to dispose of it. However, this low-grade wood can be used for energy generation as biomass.

When biomass is used in a process like gasification, the CO2 that was absorbed by trees as they grew and subsequently stored in the wood is released. However, in a BECCS process, the CO2 is captured and transported to locations where it can be stored permanently.

The overall process removes CO2 from the atmosphere while producing hydrogen. Negative emissions technologies like BECCS are considered essential for the UK and the world to reach net zero and tackle climate change.

Building a collaborative net zero economy  

How big a role hydrogen will play in the future is still uncertain. The Climate Change Committee’s (CCC) 2018 report ‘Hydrogen in a low carbon economy’ outlines four scenarios. These range from hydrogen production in 2050 being able to provide less than 100 terawatt hours (TWh) of energy a year to more than 700 TWh.

Similarly, how important biomass is to the production of hydrogen varies across different scenarios. The CCC’s report puts the amount of hydrogen produced in 2050 via BECCS between 50 TWh in some scenarios to almost 300 TWh in others. This range depends on factors such as the technology readiness level of biomass gasification. If it can be proven – technical work Drax is currently undertaking – and at scale, then BECCS can deliver on the high-end forecast of hydrogen production.

The volumes will also depend on the UK’s commitment to BECCS and sustainable biomass. The CCC’s ‘Biomass in a low carbon economy’ report offers a ‘UK BECCS hub’ scenario in which the UK accesses a greater proportion of the global biomass resource than countries with less developed carbon capture and storage systems, as part of a wider international effort to sequester and store CO2. The scenario assumes that the UK builds on its current status and continues to be a global leader in BECCS supply chains, infrastructure, and geological storage capacity. If this can be achieved, biomass and BECCS could be an intrinsic part of a hydrogen economy.

There are still developments being made in hydrogen and BECCS, which will determine how connected each is to the other and to a net zero UK. This includes the feasibility of converting HGVs and other gas systems to hydrogen, as well as the efficiency of carbon capture, transport and storage systems. The cost of producing hydrogen and carrying out BECCS are also yet to be determined.

The right government policies and incentives that encourage investment and protect jobs are needed to progress the dual development of BECCS and hydrogen. Success in both fields can unlock a collaborative net zero economy that delivers a carbon-free fuel source in hydrogen and negative emissions through BECCS.

How is carbon stored?

13 January 2022

Carbon capture

Carbon storage is the process of capturing and trapping that CO2. This can occur naturally in the form of carbon sinks like forests, oceans, and soils that store carbon. However, it can also be manually carried out through technology.   

One of the most well-established ways of storing carbon through the use of technology is by injecting CO2 into naturally occurring geological formations that can lock in or sequester the molecule on a permanent basis. Carbon storage is the final phase of the carbon capture, usage, and storage (CCUS) process.

Why do we need to store carbon?

Global bodies like the UN’s Intergovernmental Panel on Climate Change (IPCC), as well as the UK’s own Climate Change Committee, emphasise carbon capture and storage as crucial to achieving net zero emissions and meeting the Paris Agreement’s goal of limiting temperature rises to within 1.5oC.

This includes supporting forest growth through afforestation and reforestation, and other nature-based solutions to store carbon, alongside CCUS technology.

The European Commission also highlights CCUS’s role in balancing increased energy demand and continued fossil fuel use in the future, with the need to reduce greenhouse gas emissions and prevent them entering the atmosphere.

How is carbon captured and transported to storage?

In naturally occurring examples, forests and ocean fauna absorb carbon through photosynthesis. When the vegetation eventually decomposes the carbon is sequestered into soil and seabeds.

Carbon can also be captured from emissions sources such as factories or power plants. The carbon is captured either pre-combustion, where it is removed from the fuel source, or post-combustion, where it is removed from exhaust fumes in the form of CO2.

The CO2 is then converted into a supercritical state where it has the viscosity of a gas but the density of a liquid, meaning it can travel more easily through pipelines. It can also be transported via trucks and ships, but pipelines are the most efficient.

Where can carbon be stored?

Natural carbon sinks differ all over the world, from peatlands in Scotland to Pacific coral reefs to the massive forests that cover countries like Russia, Canada, and Brazil. Wooden buildings also act as carbon storage as they maintain the carbon within the wood for long time periods.

The CO2 captured by manmade technologies can also be stored in different types of geological formation: unused natural gas reserves, saline aquifers, and un-minable coal mines.

The North Sea, with its expansive layers of porous sandstone, also offers the UK alone an estimated 70 billion tonnes of potential CO2 storage space.

If negative emissions technologies (which actively remove emissions from the atmosphere) were to capture and store the equivalent amount of CO2 as the 258 million tonnes expected to remain in the UK economy in 2050, it would take up just 0.36% of the available storage space.

Years of research by the oil and gas industries mean many such geological structures have been mapped and are well understood all around the world.

Carbon storage fast facts

How is the carbon kept in place?

In nature-based carbon sinks the carbon does not always remain in one location. In a forest, for example, trees and plants will hold carbon until the end of their lifetime after which they decompose, releasing some CO2 into the atmosphere while some is sequestered into soil.

When CO2 captured through CCUS is stored several things can happen to it in a geological storage site. It can be caught in the minute intervening spaces within the rock through capillary action, or trapped by a layer of impermeable cap-rock, which prevents it from moving upwards.

CO2 may also dissolve in the water and then sinks as it is heavier than normal water. The carbonated water reacts with basaltic rocks which cover most of the ocean floor. The reaction releases elements like calcium, magnesium, and iron into the water stream. Over time, these elements combine with the dissolved CO2 to form stable carbonate minerals that permanently fill pores within the rock.

How does CO2 enter the storage sites?

The CO2 is injected into the porous rocks of depleted or unused natural gas or oil reserves, as well as saline aquifers – geologic strata, filled with brine or saline water. Porous rock is filled with holes and gaps between the grains that make up the rock. When CO2 is injected into these structures, the CO2 floods the pores, displacing the brine or remnants of oil and gas. It then spreads out and is trapped in the dome-like structures of the rock strata called anticlines.

How long can CO2 be stored?

Appropriately selected and maintained geological reservoirs are “very likely” to retain 99% of sequestered carbon for more than 100 years and are “likely” to retain 99% of sequestered carbon for more than 1,000 years, according to the 2005 Special Report on CCS by the IPCC. Another study by Nature found that more than 98% of injected CO2 will remain stored for over 10,000 years.

In natural carbon sinks, the length of time that carbon is stored varies and depends on environments being preserved. Peatland, for example, builds up over thousands of years storing carbon. However, as peatlands degrade from attempts to drain them to create arable land, as well as peat extraction for fuel, they begin to emit CO2. The lifecycle of a tree by contrast is relatively short before it decomposes and releases some CO2 back into the atmosphere.

The ability for geological storage to contain CO2 for millennia means it can truly remove and permanently store emissions.

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Forests, net zero and the science behind biomass

22 December 2021

Sustainable bioenergy

Tackling climate change and spurring a global transition to net zero emissions will require collaboration between science and industry. New technologies and decarbonisation methods must be rooted in scientific research and testing.

Drax has almost a decade of experience in using biomass as a renewable source of power. Over that time, our understanding around the effectiveness of bioenergy, its role in improving forest health and ability to deliver negative emissions, has accelerated.

Research from governments and global organisations, such as the UN’s Intergovernmental Panel on Climate Change (IPCC) increasingly highlight sustainably sourced biomass and bioenergy’s role in achieving net zero on a wide scale.

The European Commission has also highlighted biomass’ potential to provide a solution that delivers both renewable energy and healthy, sustainably managed forests.  Frans Timmermans, the executive vice-president of the European Commission in charge of the European Green Deal has emphasised it’s importance in bringing economies to net zero, saying: “without biomass, we’re not going to make it. We need biomass in the mix, but the right biomass in the mix.”

The role of biomass in a sustainable future

Moving away from fossil fuels means building an electricity system that is primarily based on renewables. Supporting wind and solar, by providing electricity at times of low sunlight or wind levels, will require flexible sources of generation, such as biomass, as well as other technologies like increased energy storage.

In the UK, the Climate Change Committee’s (CCC) Sixth Carbon Budget report lays out its Balanced Net Zero Pathway. In this lead scenario, the CCC says that bioenergy can reduce fossil emissions across the whole economy by 2 million tonnes of CO2 or equivalent emissions (MtCO2e) per year by 2035, increasing to 2.5 MtCO2e in 2045.

Foresters in working forest, Mississippi

Foresters in working forest, Mississippi

Biomass is also expected to play a crucial role in supplying biofuels and hydrogen production for sectors of the global economy that will continue to use fuel rather than electricity, such as aviation, shipping and industrial processes. The CCC’s Balanced Net Zero Pathway suggest that enough low-carbon hydrogen and bioenergy will be needed to deliver 425 TWh of non-electric power in 2050 – compared to the 1,000 TWh of power fossil fuels currently provide to industries today.

However, bioenergy can only be considered to be good for the climate if the biomass used comes from sustainably managed sources. Good forest management practises ensure that forests remain sustainable sources of woody biomass and effective carbon sinks.

A report co-authored by IPCC experts examines the scientific literature around the climate effects (principally CO2 abatement) of sourcing biomass for bioenergy from forests managed according to sustainable forest management principles and practices.

The report highlights the dual impact managed forests contribute to climate change mitigation by providing material for forest products, including biomass that replace greenhouse gas (GHG)-intensive fossil fuels, and by storing carbon in forests and in long-lived forest products.

The role of biomass and bioenergy in decarbonising economies goes beyond just replacing fossil fuels. The addition of carbon capture and storage (CCS) to bioenergy to create bioenergy with carbon capture and storage (BECCS) enables renewable power generation while removing carbon from the atmosphere and carbon cycle permanently.

The negative emissions made possible by BECCS are now seen as a fundamental part of many scenarios to limit global warming to 1.5oC above pre-industrial levels.

BECCS and the path to net zero

The IPCC’s special report on limiting global warming to 1.5oC above pre-industrial levels, emphasises that even across a wide range of scenarios for energy systems, all share a substantial reliance on bioenergy – coupled with effective land-use that prevents it contributing to deforestation.

The second chapter of the report deals with pathways that can bring emissions down to zero by the mid-century. Bioenergy use is substantial in 1.5°C pathways with or without CCS due to its multiple roles in decarbonising both electricity generation and other industries that depend on fossil fuels.

However, it’s the negative emissions made possible by BECCS that make biomass  instrumental in multiple net zero scenarios. The IPCC report highlights BECCS alongside the associated afforestation and reforestation (AR), that comes with sustainable forest management, are key components in pathways that limit climate change to 1.5oC.

Graphic showing how BECCS removes carbon from the atmosphere. Click to view/download

There are two key factors that make BECCS and other forms of emissions removals so essential: The first is their ability to neutralise residual emissions from sources that are not reducing their emissions fast enough and those that are difficult or even impossible to fully decarbonise. Aviation and agriculture are two sectors vital to the global economy with hard-to-abate emissions. Negative emissions technologies can remove an equivalent amount of CO2 that these industries produce helping balance emissions and progressing economies towards net zero.

The second reason BECCS and other negative emissions technologies will be so important in the future is in the removal of historic CO2 emissions. What makes CO2 such an important GHG to reduce and remove is that it lasts much longer in the atmosphere than any other. To help reach the Paris Agreement’s goal of limiting temperature rises to below 1.5oC removing historic emissions from the atmosphere will be essential.

In the UK, the  CCC’s 2018 report ‘Biomass in a low-carbon economy’ also points to BECCS as both a crucial source of energy and emissions abatement.

It suggests that power generation from BECCS will increase from 3 TWh per year in 2035 to 45 TWh per year in 2050. It marks a sharp increase from the 19.5 TWh that biomass (without CCS) accounted for across 2020, according to Electric Insights data. It also suggests that BECCS could sequester 1.1 tonnes of CO2 for every tonne of biomass used, providing clear negative emissions.

However, the report makes clear that unlocking the potential of bioenergy and BECCS is only possible when biomass stocks are managed in a sustainable way that, as a minimum requirement, maintains the carbon stocks in plants and soils over time.

With increased attention paid to forest management and land use, there is a growing body of evidence that points to bioenergy as a win-win solution that can decarbonise power and economies, while supporting healthy forests that effectively sequester CO2.

How bioenergy ensures sustainable forests

Biomass used in electricity generation and other industries must come from sustainable sources to offer a renewable, climate beneficial [or low carbon] source of power.

UK legislation on biomass sourcing states that operators must maintain an adequate inventory of the trees in the area (including data on the growth of the trees and on the extraction of wood) to ensure that wood is extracted from the area at a rate that does not exceed its long-term capacity to produce wood. This is designed to ensure that areas where biomass is sourced from retain their productivity and ability to continue sequestering carbon.

Ensuring that forestland remains productive and protected from land-use changes, such as urban creep, where vegetated land is converted into urban, concreted spaces, depends on a healthy market for wood products. Industries such as construction and furniture offer higher prices for higher-quality wood. While low-quality, waste wood, as well as residues from forests and wood-industry by-products, can be bought and used to produce biomass pellets.

A report by Forest 2 Market examined the relationship between demand for wood and forests’ productivity and ability to sequester carbon in the US South, where Drax sources about two-thirds of its biomass.

The report found that increased demand for wood did not displace forests in the US South. Instead, it encouraged landowners to invest in productivity improvements that increased the amount of wood fibre and therefore carbon contained in the region’s forests.

A synthesis report, which examines a broad range of research papers,  published in Forest Ecology and Management in March of 2021, concluded from existing studies that claims of large-scale damage to biodiversity from woody biofuel in the South East US are not supported. The use of these forest residues as an energy source was also found to lead to net GHG greenhouse emissions savings compared to fossil fuels, according to Forest Research.

Importantly the research shows that climate risks are not exacerbated because of biomass sourcing; in fact, the opposite is true with annual wood growth in the US South increasing by 112% between 1953 and 2015.

Delivering a “win-win solution”

The European Commission’s JRC Science for Policy literature review and knowledge synthesis report ‘The use of woody biomass for energy production in the EU’ suggests  a win-win forest bioenergy pathway is possible, that can reduce greenhouse gas emissions in the short term, while at the same time not damaging, or even improving, the condition of forest ecosystems.

However, it also makes clear “lose-lose” situations is also a possible, in which forest ecosystems are damaged without providing carbon emission reductions in policy-relevant timeframes.

Win-win management practices must benefit climate change mitigation and have either a neutral or positive effect on biodiversity. A win-win future would see the afforestation of former arable land with diverse and naturally regenerated forests.

The report also warns of trade-offs between local biodiversity and mitigating carbon emissions, or vice versa. These must be carefully navigated to avoid creating a lose-lose scenario where biodiversity is damaged and natural forests are converted into plantations, while BECCS fails to deliver the necessary negative emissions.

In a future that will depend on science working in collaboration with industries to build a net zero future continued research is key to ensuring biomass can deliver the win-win solution of renewable electricity with negative emissions while supporting healthy forests.

The jobs needed to build a net zero energy future

11 November 2021

Sustainable business

Many components are needed to tackle climate change and reach environmental milestones such as meeting the goals of the Paris Agreement. One of those components is the right workforce, large enough and with the necessary skills and knowledge to take on the green energy jobs of a low-carbon future. In 2020, the renewable energy sector employed 11.5 million people around the world, but as the industry continues to expand that workforce will only grow.

Last year, a National Grid report found that in the UK alone, 120,000 jobs will need to be filled in the low-carbon energy sector by 2030, to meet the country’s climate objectives. That figure is expected to rise to 400,000 by 2050.  The UK energy sector as a whole currently supports 738,000 jobs and much of this workforce already has the skills needed for a low carbon society . Others can be reskilled and retrained, helping to bolster the future workforce by supporting employees through the green transition.

At a global level energy sector jobs are expected to increase from 18 million to 26 million by 2050. Jobs that will span the full energy spectrum; from researching and advising on low-carbon solutions to installing and implementing them.

Here are some of the roles that will be key to the low-carbon energy transformation:

A wind farm under construction off the English coast

Wind turbine technicians

According to the International Energy Agency (IEA), wind power is this year set for a 17% increase in global energy generation compared to 2020, the biggest increase of any renewable power source. The IEA also forecasts that wind power will need to grow tenfold by 2050 if the world is to meet the goals of the Paris Agreement. It’s not surprising, therefore, that wind turbine technicians – the professionals who install, inspect, maintain, and repair wind turbines – are in high demand. In the US, wind turbine technician is the fastest-growing job in the country – with 68% growth projected over the 2020-2030 period – to give just one example.

In the UK, many wind turbine technicians have a background in engineering or experience from the wider energy sector. Although there are wind turbine technician and maintenance courses available, they are not a prerequisite, and many employers offer apprenticeships and on-the-job training – smoothing the path for energy professionals to transition into the role.

Solar panel installers

Today, solar photovoltaic (solar PV) is the biggest global employer in renewable energy, accounting for 3.8 million jobs. The IEA also reported a 23% uptick in solar PV installations around the world in 2020. In the UK, there are currently 13.2 gigawatts (GW) of installed solar power capacity. Trade association Solar Energy UK predicts this will need to rise to at least 40 GW by 2030 if the UK is to succeed in becoming a net zero economy by 2050. The trade association believes this could see the creation of 13,000 new solar energy jobs.

Solar panel installers – who carry out the important job of installing and maintaining solar PV – are essential to a low-carbon future. Many solar panel installers in the UK come from a background in electrical installation or have transitioned from engineering. While there are training courses specifically designed for solar panel installers, they are not a necessity, particularly if you already have on-the-job experience in a relevant sector. This makes a move to becoming a solar panel installer relatively easy for someone already working in energy or with a mind for engineering.

Energy consultants

Businesses of all kinds must play a role in the transition to net zero. Organisations must be able to manage their energy use and begin switching to renewable sources. As professionals who advise companies on this process, renewable energy consultants are a key part of the green energy workforce. Aspects of the job include identifying how organisations use their electric assets and helping businesses optimise those assets to build responsiveness and flexibility into energy-intensive operations. The core responsibilities of a renewable energy consultant are to reduce a company’s environmental impact while helping the business reduce energy costs and identifying opportunities.

Carbon accountants

A growing number of businesses are setting targets for reducing their greenhouse gas (GHG) emissions. But that’s only possible if you can first determine what your GHG emissions are and where they come from, which is where the relatively young field of carbon accounting comes in. Through what is known as physical carbon accounting, companies can assess the emissions their activities generate, and where in the supply chain the emissions are occurring. This allows businesses to implement more accurate actions and be realistic in their timelines for reducing emissions.

On a wider scale, accurate carbon accounting will be crucial in certifying emissions reductions or abatement, as well as in the distribution of carbon credits or penalties as whole economies push towards net zero.

Battery technology researchers

Energy storage is essential to a low-carbon energy future.  The ability to store and release energy from intermittent sources such as wind and solar will be crucial in meeting demand and balancing a renewables-driven grid. While many forms of energy storage already exist, developing electric batteries that can be deployed at scale is still a comparatively new and expanding area.

Global patenting activities in the field of batteries and other electricity storage increased at an annual rate of 14% –  four times faster than the average for technology – between 2005 and 2018. However, it’s estimated that to meet climate objectives, the world will need nearly 10,000 GW hours of battery and other electricity storage by 2040. This is 50 times the current level and research and innovation will be crucial to delivering bigger and more efficient batteries.

Farmers and foresters

How we use and manage land will be important in lowering carbon emissions and creating a sustainable future for people and the planet. Crops like corn, sugarcane, and soybean can serve as feedstock for biofuel and bioenergy, and farming by-products such as cow manure can be used in the development of biofuel.

Techniques adopted in the agricultural sector will also be important in optimising soil sequestration capabilities while ensuring it is nutrient-rich enough to grow food. These techniques include the use of biochar, a solid form of charcoal produced by heating biomass without oxygen. Research indicates that biochar can sequester carbon in the soil for centuries or longer. It also helps soil retain water and could contribute to reducing the use of fertilisers by making the soil more nutrient-dense.

Forests, meanwhile, provide material for industries like construction, the by-products from which can serve as feedstock for woody biomass, primarily in the shape of low-grade wood that would otherwise remain unused. Sustainably managed forests, such as those from which Drax sources its biomass, have two-fold importance. They both enable woody biomass for bioenergy and ensure CO2 is removed from the atmosphere as part of the natural carbon cycle.

Biofuel engineers and scientists

Farmers and foresters provide feedstock for biofuels, but it’s biofuel scientists and engineers who research, develop, and enhance them, opening the door to alternative fuels for vehicles, heating, and even jet engines.

According to the IEA, production of biofuel that can be used as an alternative to fossil fuels in the transport sector grew 6% in 2019. However, the organisation forecasts that production will need to increase 10% annually until 2030to be in line with Paris Agreement climate targets.

Scientific innovations that can help boost the production of biofuel around the world, therefore, continues to be vital. As is the work of biofuel engineers who assess and improve existing biofuel systems and develop new ones that can replace fossil fuels like petrol and diesel.

The wealth of knowledge around fuels in the oil and gas industries means there is ample opportunity for scientists and engineers who work with fossil fuels to bring their skills to crucial low-carbon roles.

Geologists

The overriding goal of the Paris Agreement is to limit global warming to “well below” 2 and preferably to 1.5 degrees Celsius, compared to pre-industrial levels. This is an objective the IEA has said will be “virtually impossible” to fulfil without carbon capture and storage (CCS) technologies. CCS entails capturing CO2 and transporting it for safe and permanent underground storage in geological formations such as depleted oil and gas fields, coal seams, and saline aquifers.

According to the Global CCS Institute, the world will need a 100-fold increase on the 27 CCS project currently in operation by 2050. Knowledge and research into rock types, formations, and reactivity will be important in helping identify sites deep underground that can be used for safe, permanent carbon storage, and sequestration. Skills and expertise gained in the oil and gas industries will allow professionals in these sectors to make the switch from careers in fossil fuel to roles that help power a net zero economy.  

Employees working at Drax Power Station

Chemists

The role of chemists is also vital to decarbonisation. Knowledge and research around CO2 is a potent force in the effort to reduce and remove it from the atmosphere.

Technologies like CCS, bioenergy with carbon capture and storage (BECSS) and direct air carbon capture and storage (DACCS) are based around such research. Carbon capture processes are chemical reactions between emissions streams and solvents, often based on amines, and GHGs. Understanding and controlling these processes makes chemistry a key component of delivering carbon capture at the scale needed to help meet climate targets.

Chemists’ role in decarbonisation is far from limited to carbon capture methods. From battery technology to reforestation, chemists’ understanding of the elements can help drive action against climate change.

Bringing together disciplines

Tackling climate change on the scale needed to achieve the aims of the Paris Agreement depends on collaboration between industries, countries, and disciplines. Decarbonisation projects such as the UK’s East Coast Cluster, which encompasses both Zero Carbon Humber and Net Zero Teesside, fuse engineering and construction jobs with scientific and academic work.

Zero Carbon Humber, which brings together 12 organisations, including Drax, is expected to create as many as 47,800 jobs in the region by 2027. Among these are construction sector jobs for welders, pipefitters, machine installers and technicians. In addition, indirect jobs are predicted to be created across supply chains, from material manufacturing to the logistics of supporting a workforce.

Meeting climate challenges and delivering projects on the scale of Zero Carbon Humber, depends on creating an energy workforce that combines the knowledge of the past with the green energy skills of the future.

Drax’s apprenticeships have readied workers for the energy sector for decades, and will continue to do so as we build a low-carbon future. Options include four-year technical apprenticeships in mechanical, electrical, and control and instrumentation engineering. Getting on-the-job training and practical experience, apprentices receive a nationally recognised qualification, such as a BTEC or an NVQ Level 3, at the end of the programme.

Apprentices at Drax Power Station [2021]

The workforce needed to make low carbon societies a reality will be a diverse one – stretching from apprentices to experienced professionals with a background in traditional or renewable energy. It will also span every aspect of the renewable energy field, from the chemists and biofuel scientists who develop key technologies to the solar panel installers and wind turbine technicians who fit and maintain the necessary equipment.

The skills needed to take on these roles are already plentiful in the UK and around the world. Overcoming challenges on the road to net zero requires refocussing these existing talents, skills, and careers towards a new goal.

Transporting carbon – How to safely move CO2 from the atmosphere to permanent storage

15 October 2021

Carbon capture

Key points

  • Carbon capture usage and storage (CCUS) offers a unique opportunity to capture and store the UK’s emissions and help the country reach its climate goals.
  • Carbon dioxide (CO2) can be stored in geological reservoirs under the North Sea, but getting it from source to storage will need a large and safe CO2 transportation network.
  • The UK already has a long history and extensive infrastructure for transporting gas across the country for heating, cooking and power generation.
  • This provides a foundation of knowledge and experience on which to build a network to transport CO2.

Across the length of the UK is an underground network similar to the trainlines and roadways that crisscross the country above ground. These pipes aren’t carrying water or broadband, but gas. Natural gas is a cornerstone of the UK’s energy, powering our heating, cooking and electricity generation. But like the country’s energy network, the need to reduce emissions and meet the UK’s target of net zero emissions by 2050 is set to change this.

Today, this network of pipes takes fossil fuels from underground formations deep beneath the North Sea bed and distributes it around the UK to be burned – producing emissions. A similar system of subterranean pipelines could soon be used to transport captured emissions, such as CO2, away from industrial clusters around factories and power stations, locking them away underground, permanently and safely.

Conveyer system at Drax Power Station transporting sustainable wood pellets

The rise of CCUS technology is the driving force behind CO2 transportation. The process captures CO2 from emissions sources and transports it to sites such as deep natural storage enclaves far below the seabed.

Bioenergy with carbon capture and storage (BECCS) takes this a step further. BECCS uses sustainable biomass to generate renewable electricity. This biomass comes from sources, such as forest residues or agricultural waste products, which remove CO2 from the atmosphere as they grow. Atmospheric CO2 released in the combustion of the biomass is then captured, transported and stored at sites such as deep geological formations.

Across the whole BECCS process, CO2 has gone from the atmosphere to being permanently trapped away, reducing the overall amount of CO2 in the atmosphere and delivering what’s known as negative emissions.

BECCS is a crucial technology for reaching net zero emissions by 2050, but how can we ensure the CO2 is safely transported from the emissions source to storage sites?

Moving gases around safely

Moving gases of any kind through pipelines is all about pressure. Gases always travel from areas of high pressure to areas of low pressure. By compressing gas to a high pressure, it allows it to flow to other locations. Compressor stations along a gas pipeline help to maintain right the pressure, while metering stations check pressure levels and look out for leaks.

The greater the pressure difference between two points, the faster gases will flow. In the case of CO2, high absolute pressures also cause it to become what’s known as a supercritical fluid. This means it has the density of a liquid but the viscosity of a gas, properties that make it easier to transport through long pipelines.

Since 1967 when North Sea natural gas first arrived in the UK, our natural gas transmission network has expanded considerably, and is today made up of almost 290,000 km of pipelines that run the length of the country. Along with that physical footprint is an extensive knowledge pool and a set of well-enforced regulations monitoring their operation.

While moving gas through pipelines across the country is by no means new, the idea of CO2 transportation through pipelines is. But it’s not unprecedented, as it has been carried out since the 1980s at scale across North America. In contrast to BECCS, which would transport CO2 to remove and permanently store emissions, most of the CO2 transport in action today is used in oil enhanced recovery – a means of ejecting more fossil fuels from depleted oil wells. However, the principle of moving CO2 safely over long distances remains relevant – there are already 2,500 km of pipelines in the western USA, transporting as much as 50 million tonnes of CO2 a year.

“People might worry when there is something new moving around in the country, but the science community doesn’t have sleepless nights about CO2 pipelines,” says Dr Hannah Chalmers, from the University of Edinburgh. “It wouldn’t explode, like natural gas might, that’s just not how the molecule works. If it’s properly installed and regulated, there’s no reason to be concerned.”

CO2 is not the same as the methane-based natural gas that people use every day. For one, it is a much more stable, inert molecule, meaning it does not react with other molecules, and it doesn’t fuel explosions in the same way natural gas would.

CO2 has long been understood and there is a growing body of research around transporting and storing it in a safe efficient way that can make CCUS and BECCS a catalyst in reducing the UK’s emissions and future-proofing its economy.

Working with CO2 across the UK

Working with CO2 while it is in a supercritical state mean it’s not just easier to move around pipes. In this state CO2 can also be loaded onto ships in very large quantities, as well as injected into rock formations that once trapped oil and gas, or salt-dense water reserves.

Decades of extracting fossil fuels from the North Sea means it is extensively mapped and the rock formations well understood. The expansive layers of porous sandstone that lie beneath offer the UK an estimated 70 billion tonnes of potential CO2 storage space – something a number of industrial clusters on the UK’s east coast are exploring as part of their plans to decarbonise.

Source: CCS Image Library, Global CCS Institute [Click to view/download]

Drax is already running a pilot BECCS project at its power station in North Yorkshire. As part of the Zero Carbon Humber partnership and wider East Coast Cluster, Drax is involved in the development of large scale carbon storage capabilities in the North Sea that can serve the Humber and Teesside industrial clusters. As Drax moves towards its goal of becoming carbon negative by 2030, transporting CO2 safely at scale is a key focus.

“Much of the research and engineering has already been done around the infrastructure side of the project,” explains Richard Gwilliam, Head of Cluster Development at Drax. “Transporting and storing CO2 captured by the BECCS projects is well understood thanks to extensive engineering investigations already completed both onshore and offshore in the Yorkshire region.”

This also includes research and development into pipes of different materials, carrying CO2 at different pressures and temperatures, as well as fracture and safety testing.

The potential for the UK to build on this foundation and progress towards net zero is considerable. However, for it to fully manifest it will need commitment at a national level to building the additional infrastructure required. The results of such a commitment could be far reaching.

In the Humber alone, 20% of economic value comes from energy and emissions-intensive industries, and as many as 360,000 jobs are supported by industries like refining, petrochemicals, manufacturing and power generation. Putting in place the technology and infrastructure to capture, transport and store emissions will protect those industries while helping the UK reach its climate goals.

It’s just a matter of putting the pipes in place.

Go deeper: How do you store CO2 and what happens to it when you do?

What is direct air carbon capture and storage (DACS)?

9 July 2021

Carbon capture

What is direct air carbon capture and storage (DACS)?

Direct air carbon capture and storage (DACS, sometimes referred to as DAC or DACCS) is one of the few technologies that can remove carbon dioxide (CO2) from the atmosphere. Unlike other carbon removal technologies that capture CO2 emissions during the process of generating electricity or heat, DACS can be deployed anywhere in the world it can tap into a supply of electricity.

CO2 removal is crucial to meeting the international climate goals set by the 2015 Paris Agreement. But it’s not enough just to cut CO2 emissions, to achieve net zero, it will also be necessary to remove the CO2 that two centuries of industrialisation have released into the environment. As a technology that removes more CO2 from the atmosphere than it releases – assuming it is powered by green electricity – DACS has the potential to play a key role in this process.

Key direct air capture facts

How does DACS work?

DACS could be described as a form of industrial photosynthesis. Just as plants use photosynthesis to convert sunlight and CO2 into sugar, DACS systems use electricity to remove CO2 from the atmosphere using fans and filters.

Air is drawn into the DACS system using an industrial scale fan. Liquid DACS systems pass the air through a chemical solution which removes the CO2 and returns the rest of the air back into the atmosphere.

Solid DACS systems captures CO2 on the surface of a filter covered in a chemical agent, where it then forms a compound. The new compound is heated, releasing the CO2 to be captured and separating it from the chemical agent, which can then be recycled.

The captured CO2 can then be compressed under very high pressure and pumped via pipelines into deep geological formations. This permanent storage process is known as ‘sequestration’.

Alternatively, the CO2 can be pumped under low pressure for immediate use in commercial processes, such as carbonating drinks or cement manufacturing.

A 2021 study by the Coalition for Negative Emissions shows that DACS could provide at least 1Gt of sustainable negative emissions by 2025

DACS fast facts

What role can DACS play in decarbonisation?

CO2 is in the air at the same concentration everywhere in the world. This means that DACS plants can be located anywhere, unlike carbon capture systems that remove CO2 from industrial processes at source.

There are 15 DACS plants currently in operation worldwide – Climeworks operates three in Switzerland, Iceland and Italy. Together, these small-scale plants capture approximately 9,000 tonnes of CO2 per annum. The first large-scale plant, currently being developed in the Permian Basin, Texas, is expected to capture 1,000,000 tonnes (one megatonne) per annum when it becomes operational in 2025.

At just 0.04%, the concentration of CO2 in the atmosphere is very dilute which makes removing and storing it a challenge. This means that DACS costs significantly more than some other CO2 capture technologies – between $200 and $600 (£156-468) per metric tonne. The process also requires large amounts of energy, which adds to the demand for electricity.

However, DACS has the potential to become an important piece in the jigsaw of CO2 removal technologies and techniques that includes nature-based solutions such as planting forests, along with bioenergy with carbon capture and storage (BECCS), soil sequestration and ‘blue carbon’ marine initiatives.

Go deeper

Button: What is bioenergy with carbon capture and storage (BECCS)?