Tag: technology

Forests, net zero and the science behind biomass

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.

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

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 COreleased 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)?

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)?

The myths, legends and reality of Cruachan Power Station’s mural

Down the kilometre-long tunnel that burrows into the dark rock of Ben Cruachan, above the giant rumbling turbines, sits something unusual for a power station: a work of art.

The wood and gold-leaf mural might seem at odds with the yellow metal turbines, granite cavern walls, and noise and heat around it, but it’s closely connected to the power station and its ties to the surrounding landscape.

The entrance tunnel might take engineers and machines to the heart of Ben Cruachan, but the mural transports viewers to the mountain’s mythical past. It tells the story of how this remarkable engineering achievement came to help power the country.

The narrative of the mural

Much like the machines and physical environment surrounding it, the Cruachan mural is big, measuring 14.6 metres long by 3.6 metres tall. Combining wood, plastic and gold leaf, the relief is interspersed with Celtic crosses, textures evocative of granite rock and gold orbs that resemble the urban lights Cruachan helps to power. Running from left to right, it tells a linear narrative that spans the history of the mountain.

An artist’s impression of the mural in the Visitor Centre at Cruachan

In the first of the mural’s three segments is a Scottish red deer, a native species that still thrives in Scotland today. Below it is the figure of the Cailleach Bheur, a legendary old woman or hag found across Gaelic mythology in Scotland, Ireland and on the Isle of Man. The Cailleach has a symbolic representation of a variety of roles in different folklores, but she commonly appears as a personification of winter, and with that, as a source of destruction.

In the context of Ben Cruachan, Cailleach Bheur is often taken to mean the ‘Old Hag of The Ridges,’ a figure who acts as the mythical guardian of a spring on the mountain’s peak. The mural tells her story, of how she was tasked to cover the well with a slab of stone at sundown and lift it away at sunrise. One evening, however, she fell asleep and failed to cover the well, allowing it to overflow and cause water to cascade down the mountain, flooding the valley below and drowning the people and their cattle.

The mural within the Turbine Hall at Cruachan Power Station undergoing maintenance  [November 2018]

This serves as the legendary origins of Loch Awe, from which Cruachan power station pumps water to the upper reservoir when there’s excess electricity on the grid.

The story claims the water washed a path through to the sea, creating the Pass of Brander. The site of a 1308 battle in the Scottish Wars of Independence, where Robert the Bruce defeated the English-aligned MacDougall and Macnaghten clans.

The mythical first section of the mural is separated by a Celtic-style cross from the modern second segment, which portrays the power station’s construction within Ben Cruachan. Here, four figures represent the four lead engineers of the project from the firms James Williamson & Partners, William Tawse Ltd, Edmund Nuttall Ltd and Merz & McLellan. They stand by the mountain, a roughly cut path running through its core.

At the base of the mural are the faces of 15 men lying on their sides. These are the  15 who were killed in  1962 when the ceiling of the turbine hall caved in during construction. Their uniform expressionless faces, however, turn them into symbols of the 30-plus workers who died while digging and blasting the power station’s tunnels and constructing the dam at the upper reservoir.

Next to this is a fairy tale portrayal of Queen Elizabeth II, who wears a gold grown and holds a sceptre from which electricity flows in a glowing lightning bolt through rock, commanding the power station into life.

The final third of the mural shows the whole power station system within the mountain. The upper reservoir sits nestled in the slopes of Ben Cruachan with water flowing down the mountain to the four turbines and Loch Awe below. Viewed as a whole, the mural takes the audience from mythology to the modern power station, which continues to play a vital role in the electricity system today.

Carving the Cruachan mural

The mural was created by artist Elizabeth Falconer, who was commissioned to create it to celebrate the power station’s opening by the Queen on 15 October 1965. At the time, only two of Cruachan’s four 100 megawatt (MW) reversible turbines were completed and operational, but it was still the first station of its kind to operate at such a scale. Two of the power station’s  turbines were modified with increased capacities meaning Cruachan can both use and generate up to 440 MW.

HRH Queen Elizabeth II opening Cruachan in 1965

HRH Queen Elizabeth II opening Cruachan on 15 October 1965

The project came to Falconer through her husband, a native of Aberdeen who worked as an architect partner to one of Cruachan’s engineering firms. The brief simply requested she create a piece to fill the empty space on the wall of the turbine hall. Deciding to dive into the history and mythology of the mountain, she initially carved the mural in London and only ventured into Hollow Mountain years after it was first put in place, to make renovations on the work.

Cruachan Power Station was a visionary idea and represented a considerable technical and engineering achievement when it opened. The designs and construction of the reversable turbines put this site at the cutting end of modern energy technology.

So, it’s fitting the mural appears distinctly modern in its design, yet tells a story that connects this modern power station to the ancient rock it lives within.

It’s Cruachan’s mural’s location inside the mountain that makes it so unique as a work of art. However, at a time when the electricity grid is changing to an increasingly renewable system, based more around weather and geography, the connections the mural makes between Scotland’s landscape and the modern power station, make it relevant beyond the turbine cavern.



Find out more about Cruachan Power Station

Could hydrogen power stations offer flexible electricity for a net zero future?

Pipework in a chemical factory

We’re familiar with using natural gas every day in heating homes, powering boilers and igniting stove tops. But this same natural gas – predominantly methane – is also one of the most important sources of electricity to the UK. In 2019 gas generation accounted for 39% of Great Britain’s electricity mix. But that could soon be changing.

Hydrogen, the super simple, super light element, can be a zero-carbon emissions source of fuel. While we’re used to seeing it in everyday in water (H2O), as a gas it has been tested as an alternative to methane in homes and as a fuel for vehicles.

Could it also replace natural gas in power stations and help keep the lights on?

The need for a new gas

Car arriving at hydrogen gas station

Hydrogen fuel station

Natural gas has been the largest single source of electricity in Great Britain since around 2000 (aside from the period 2012-14 when coal made a resurgence due to high gas prices). The dominance of gas over coal is in part thanks to the abundant supply of it in the North Sea. Along with carbon pricing, domestic supply makes gas much cheaper than coal, and much cleaner, emitting as much as 60% less CO2 than the solid fossil fuel.

Added to this is the ability of gas power stations to start up, change their output and shut down very quickly to meet sudden shifts in electricity demand. This flexibility is helpful to support the growth of weather-dependant renewable sources of power such as wind or solar. The stability gas brings has helped the country decarbonise its power supply rapidly.

Hydrogen, on the other hand, can be an even cleaner fuel as it only releases water vapour and nitrous oxide when combusted in large gas turbines. This means it could offer a low- or zero-carbon, flexible alternative to natural gas that makes use of Great Britain’s existing gas infrastructure. But it’s not as simple as just switching fuels.

Switching gases

Some thermal power stations work by combusting a fuel, such as biomass or coal, in a boiler to generate intense heat that turns water into high-pressure steam which then spins a turbine. Gas turbines, however, are different.

Engineer works on a turbine at Drax Power Station

Instead of heating water into steam, a simple gas turbine blasts a mix of gas, plus air from the surrounding atmosphere, at high pressure into a combustion chamber, where a chemical reaction takes place – oxygen from the air continuously feeding a gas-powered flame. The high-pressure and hot gasses then spin a turbine. The reaction that takes place inside the combustion chamber is dependent on the chemical mix that enters it.

“Natural gas turbines have been tailored and optimised for their working conditions,” explains Richard Armstrong, Drax Lead Engineer.

“Hydrogen is a gas that burns in the same way as natural gas, but it burns at different temperatures, at different speeds and it requires different ratios of oxygen to get the most efficient combustion.”

Switching a power station from natural gas to hydrogen would take significant testing and refining to optimise every aspect of the process and ensure everything is safe. This would no doubt continue over years, subtly developing the engines over time to improve efficiency in a similar way to how natural gas combustion has evolved. But it’s certainly possible.

What may be trickier though is providing the supply of hydrogen necessary to power and balance the country’s electricity system. 

Making hydrogen

Hydrogen is the most abundant element in the universe. But it’s very rare to find it on its own. Because it’s so atomically simple, it’s highly reactive and almost always found naturally bonded to other elements.

Water is the prime example: it’s made up of two hydrogen atoms and one oxygen atom, making it H2O. Hydrogen’s tendency to bond with everything means a pure stream of it, as would be needed in a power station, has to be produced rather than extracted from underground like natural gas.

Hydrogen as a gas at standard temperature and pressure is known by the symbol H2.

A power station would also need a lot more hydrogen than natural gas. By volume it would take three times as much hydrogen to produce the same amount of energy as would be needed with natural gas. However, because it is so light the hydrogen would still have a lower mass.

“A very large supply of hydrogen would be needed, which doesn’t exist in the UK at the moment,” says Rachel Grima, Research & Innovation Engineer at Drax. “So, at the same time as converting a power plant to hydrogen, you’d need to build a facility to produce it alongside it.”

One of the most established ways to produce hydrogen is through a process known as steam methane reforming. This applies high temperatures and pressure to natural gas to break down the methane (which makes up the majority of natural gas) into hydrogen and carbon dioxide (CO2).

The obvious problem with the process is it still emits CO2, meaning carbon capture and storage (CCS) systems are needed if it is to be carbon neutral.

“It’s almost like capturing the CO2 from natural gas before its combusted, rather than post-combustion,” explains Grima. “One of the advantages of this is that the CO2 is at a much higher concentration, which makes it much easier to capture than in flue gas when it is diluted with a lot of nitrogen.”

Using natural gas in the process produces what’s known as ‘grey hydrogen’, adding carbon capture to make the process carbon neutral is known as ‘blue hydrogen’ – but there are ways to make it with renewable energy sources too.

Electrolysis is already an established technology, where an electrical current is used to break water down into hydrogen and oxygen. This ‘green hydrogen’ cuts out the CO2 emissions that come from using natural gas. However, like charging an electric vehicle, the process is only carbon-neutral if the electricity powering it comes from zero carbon sources, such as nuclear, wind and solar.

It’s also possible to produce hydrogen from biomass. By putting biomass under high temperatures and adding a limited amount of oxygen (to prevent the biomass combusting) the biomass can be gasified, meaning it is turned into a mix of hydrogen and CO2. By using a sustainable biomass supply chain where forests absorb the equivalent of the CO2 emitted but where some fossil fuels are used within the supply chain, the process becomes low carbon.

Carbon capture use and storage (CCUS) Incubation Area, Drax Power Station

Carbon capture use and storage (CCUS) Incubation Area, Drax Power Station

CCS can then be added to make it carbon negative overall, meaning more CO2 is captured and stored at forest level and in below-ground carbon storage than is emitted throughout its lifecycle. This form of ‘green hydrogen’ is known as bioenergy with carbon capture and storage (BECCS) hydrogen or negative emissions hydrogen.

There are plenty of options for making hydrogen, but doing it at the scale needed for power generation and ensuring it’s an affordable fuel is the real challenge. Then there is the issue of transporting and working with hydrogen.

“The difficulty is less in converting the UK’s gas power stations and turbines themselves. That’s a hurdle but most turbine manufacturers already in the process of developing solutions for this,” says Armstrong.

“The challenge is establishing a stable and consistent supply of hydrogen and the transmission network to get it to site.”

Working with the lightest known element

Today hydrogen is mainly transported by truck as either a gas or cooled down to minus-253 degrees Celsius, at which point it becomes a liquid (LH2). However, there is plenty of infrastructure already in place around the UK that could make transporting hydrogen significantly more efficient.

“The UK has a very advanced and comprehensive gas grid. A conversion to hydrogen would be more economic if you could repurpose the existing gas infrastructure,” says Hannah Steedman, Innovation Engineer at Drax.

“The most feasible way to feed a power station is through pipelines and a lot of work is underway to determine if the current natural gas network could be used for hydrogen.”

Gas stove

Hydrogen is different to natural gas in that it is a very small and highly reactive molecule,  therefore it needs to be treated differently. For example, parts of the existing gas network are made of steel, a metal which hydrogen reacts with, causing what’s known as hydrogen embrittlement, which can lead to cracks and failures that could potentially allow gas to escape. There are also factors around safety and efficiency to consider.

Like natural gas, hydrogen is also odourless, meaning it would need to have an odourant added to it. Experimentation is underway to find out if mercaptan, the odourant added to natural gas to give it a sulphuric smell, is also compatible with hydrogen.

But for all the challenges that might come with switching to hydrogen, there are huge advantages.

The UK’s gas network – both power generation and domestic – must move away from fossil fuels if it is to stop emitting CO2 into the atmosphere, and for the country to reach net zero by 2050. While the process will not be as simple as switching gases, it creates an opportunity to upgrade the UK’s gas infrastructure – for power, in homes and even as a vehicle fuel.

It won’t happen overnight, but hydrogen is a proven energy fuel source. While it may take time to ramp up production to a scale which can meet demand, at a reasonable cost, transitioning to hydrogen is a chance to future-proof the gas systems that contributes so heavily to the UK’s stable power system.

What are negative emissions?

Negative emissions

What are negative emissions?

In order to meet the long-term climate goals laid out in the Paris Agreement, there is a need to not only reduce the emission of harmful greenhouse gases into the air, but actively work to remove the excess carbon dioxide (CO2) currently in the atmosphere, and the CO2 that will continue to be emitted as economies work to decarbonise.

The process of greenhouse gas removal (GGR) or CO2 removal (CDR) from the atmosphere is possible through negative emissions, where more CO2 is taken out than is being put into the atmosphere. Negative emissions can be achieved through a range of nature-based solutions or through man-made technologies designed to remove CO2 at scale.

What nature-based solutions exist to remove CO2 from the atmosphere?

One millennia-old way of achieving negative emissions is forests. Trees absorb carbon when they grow, either converting this to energy and releasing oxygen, or storing it over their lifetime. This makes forests important tools in limiting and potentially reducing the amount of CO2 in the atmosphere. Planting new forests and regenerating forests has a positive effect on the health of the world as a result.

However, this can also go beyond forests on land. Vegetation underwater has the ability to absorb and store CO2, and seagrasses can in fact store up to twice as much carbon as forests on land – an approach to negative emissions called ‘blue carbon’.

Key negative emissions facts

 

Did you know?

Bhutan is the only carbon negative country in the world – its thick forests absorb three times the amount of CO2 the small country emits.

What man-made technologies can deliver negative emissions?

Many scientists and experts agree one of the most promising technologies to achieve negative emissions is bioenergy with carbon capture and storage (BECCS). This approach uses biomass – sourced from sustainably managed forests – to generate electricity. As the forests used to create biomass absorb CO2 while growing, the CO2 released when it is used as fuel is already accounted for, making the whole process low carbon.

By then capturing and storing any CO2 emitted (often in safe underground deposits), the process of electricity generation becomes carbon negative, as more carbon has been removed from the atmosphere than has been added.

Direct air carbon capture and storage (DACCS) is an alternative technological solution in which CO2 is captured directly from the air and then transported to be stored or used. While this could hold huge potential, the technology is currently in its infancy, and requires substantial investment to make it a more widespread practice.

The process of removing CO2 from the atmosphere is known as negative emissions, because more CO2 is being taken out of the atmosphere than added into it.

How much negative emissions are needed?

According to the Intergovernmental Panel on Climate Change, negative emissions technologies could be required to capture 20 billion tonnes of carbon annually to help prevent catastrophic changes in the climate between now and 2050.

Negative emissions fast facts

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What is carbon capture usage and storage?

Carbon capture

What is carbon capture usage and storage?

Carbon capture and storage (CCS) is the process of trapping or collecting carbon emissions from a large-scale source – for example, a power station or factory – and then permanently storing them.

Carbon capture usage and storage (CCUS) is where captured carbon dioxide (CO2) may be used, rather than stored, in other industrial processes or even in the manufacture of consumer products.

How is carbon captured?

Carbon can be captured either pre-combustion, where it is removed from fuels that emit carbon before the fuel is used, or post-combustion, where carbon is captured directly from the gases emitted once a fuel is burned.

Pre-combustion carbon capture involves solid fossil fuels being converted into a mixture of hydrogen and carbon dioxide under heat pressure. The separated CO2 is

captured and transported to be stored or used.

Post-combustion carbon capture uses the addition of other materials (such as solvents) to separate the carbon from flue gases produced as a result of the fuel being burned. The isolated carbon is then transported (normally via pipeline) to be stored permanently –  usually deep underground – or used for other purposes.

Carbon capture and storage traps and removes carbon dioxide from large sources and most of that CO2 is not released into the atmosphere.

 What can the carbon be used for?

Once carbon is captured it can be stored permanently or used in a variety of different ways. For example, material including carbon nanofibres and bioplastics can be produced from captured carbon and used in products such as airplanes and bicycles, while several start-ups are developing methods of turning captured CO2 into animal feed.

Captured carbon can even assist in the large-scale production of hydrogen, which could be used as a carbon-neutral source of transport fuel or as an alternative to natural gas in power generation.

Key carbon capture facts

Where can carbon be stored?

Carbon can be stored in geological reserves, commonly naturally occurring underground rock formations such as unused natural gas reservoirs, saline aquifers, or ‘unmineable’ coal beds. The process of storage is referred to as sequestration.

The underground storage process means that the carbon can integrate into the earth through mineral storage, where the gas chemically reacts with the minerals in the rock formations and forms new, solid minerals that ensure it is permanently and safely stored.

Carbon injected into a saline aquifer dissolves into the water and descends to the bottom of the aquifer in a process called dissolution storage.

According to the Global CCS Institute, over 25 million tonnes of carbon captured from the power and industrial sectors was successfully and permanently stored in 2019 across sites in the USA, Norway and Brazil. 

What are the benefits of carbon storage?

CO2 is a greenhouse gas, which traps heat in our atmosphere, and therefore contributes to global warming. By capturing and storing carbon, it is being taken out of the atmosphere, which reduces greenhouse gas levels and helps mitigate the effects of climate change.

Carbon capture fast facts

  • CCUS is an affordable way to lower CO2 emissions – fighting climate change would cost 70% more without carbon capture technologies
  • The largest carbon capture facility in the world is the Petra Nova plant in Texas, which has captured a total of 5 million tonnes of CO2, since opening in 2016
  • Drax Power Station is trialling Europe’s biggest bioenergy carbon capture usage and storage project (BECCS), which could remove and capture more than 16 million tonnes of CO2 a year by the mid 2030s, delivering a huge amount of the negative emissions the UK needs to meet net zero

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What is decarbonisation?

Decarbonisation

What is decarbonisation?

Decarbonisation is the term used for the process of removing or reducing the carbon dioxide (CO2) output of a country’s economy. This is usually done by decreasing the amount of CO2 emitted across the active industries within that economy. 

Why is decarbonisation important?

Currently, a wide range of sectors – industrial, residential and transport – run largely on fossil fuels, which means that their energy comes from the combustion of fuels like coal, oil or gas.

The CO2 emitted from using these fuels acts as a greenhouse gas, trapping in heat and contributing to global warming. By using alternative sources of energy, industries can reduce the amount of CO2 emitted into the atmosphere and can help to slow the effects of climate change.

Key decarbonisation facts

Why target carbon dioxide?

 There are numerous greenhouse gases that contribute to global warming, however CO2 is the most prevalent. As of 2018, carbon levels are the highest they’ve been in 800,000 years.

The Paris Agreement was created to hold nations accountable in their efforts to decrease carbon emissions, with the central goal of ensuring that temperatures don’t rise 2 degrees Celsius above pre-industrial level.

With 195 current signatories, economies have begun to factor in the need for less investment in carbon, with the UK leading the G20 nations in decarbonising its economy in the 21st century.

How is decarbonisation carried out?

There are numerous energy technologies that aim to reduce emissions from industries, as well as those that work towards reducing carbon emissions from the atmosphere.

Decarbonisation has had the most progress in electricity generation because of the growth of renewable sources of power, such as wind turbines, solar panels and coal-to-biomass upgrades, meaning that homes and businesses don’t have to rely on fossil fuels. Other innovations, such as using batteries and allowing homes to generate and share their own power, can also lead to higher rates of decarbonisation. As the electricity itself is made cleaner, it therefore assists electricity users themselves to become cleaner in the process.

Other approaches, such as reforestation or carbon capture and storage, help to pull existing carbon from the air, to neutralise carbon output, or in some cases, help to make electricity generation – and even entire nations – carbon negative.

Alternative power options means that homes and businesses don’t have to rely on traditional carbon fuels.

What is the future of decarbonisation?

For decarbonisation to be more widely adopted as a method for combating climate change, there needs to be structural economical change, according to Deloitte Access Economics. Creating more room for decarbonisation through investing in alternative energies means that “there are a multitude of job-rich, shovel-ready, stimulus opportunities that also unlock long-term value”.

 Decarbonisation fast facts

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14 moments that electrified history

Electricity is such a universal and accepted part of our lives it’s become something we take for granted. Rarely do we stop to consider the path it took to become ubiquitous, and yet through the course of its history there have been several eureka moments and breakthrough inventions that have shaped our modern lives. Here are some of the defining moments in the development of electricity and power.

2750 BC – Electricity first recorded in the form of electric fish

Ancient Egyptians referred to electric catfish as the ‘thunderers of the Nile’, and were fascinated by these creatures. It led to a near millennia of wonder and intrigue, including conducting and documenting crude experiments, such as touching the fish with an iron rod to cause electric shocks.

500 BC – The discovery of static electricity

Around 500 BC Thales of Miletus discovered that static electricity could be made by rubbing lightweight objects such as fur or feathers on amber. This static effect remained unknown for almost 2,000 years until around 1600 AD, when William Gilbert discovered static electricity in earnest.

1600 AD – The origins of the word ‘electricity’

The Latin word ‘electricus’, which translates to ‘of amber’ was used by the English physician, William Gilbert to describe the force exerted when items are rubbed together. A few years later, English scientist Thomas Browne translated this into ‘electricity’ in his written investigations in the field.

1751 – Benjamin Franklin’s ‘Experiments and Observations on Electricity’

This book of Benjamin Franklin’s discoveries made about the behaviour of electricity was published in 1751. The publication and translation of American founding father, scientist and inventor’s letters would provide the basis for all further electricity experimentation. It also introduced a host of new terms to the field including positive, negative, charge, battery and electric shock.

1765 – James Watt transforms the Industrial Revolution

Watt studies Newcomen’s engine

James Watt transformed the Industrial Revolution with the invention of a modified Newcome engine, now known as the Watt steam engine. Machines no longer had to rely on the sometimes-temperamental wind, water or manpower – instead steam from boiling water could drive the pistons back and forth. Although Watt’s engine didn’t generate electricity, it created a foundation that would eventually lead to the steam turbine – still the basis of much of the globe’s electricity generation today.

James Watt’s steam engine

Alessandro Volta

1800 – Volta’s first true battery

Documented records of battery-like objects date back to 250 BC, but the first true battery was invented by Italian scientist Alessandro Volta in 1800. Volta realised that a current was created when zinc and silver were immersed in an electrolyte – the principal on which chemical batteries are still based today.

1800s – The first electrical cars

Breakthroughs in electric motors and batteries in the early 1800s led to experimentation with electrically powered vehicles. The British inventor Robert Anderson is often credited with developing the first crude electric carriage at the beginning of the 19th century, but it would not be until 1890 that American chemist William Morrison would invent the first practical electric car (though it closer resembled a motorised wagon), boasting a top speed of 14 miles per hour.

Michael Faraday

1831 – Michael Faraday’s electric dynamo

Faraday’s invention of the electric dynamo power generator set the precedent for electricity generation for centuries to come. His invention converted motive (or mechanical) power – such as steam, gas, water and wind turbines – into electromagnetic power at a low voltage. Although rudimentary, it was a breakthrough in generating consistent, continuous electricity, and opened the door for the likes of Thomas Edison and Joseph Swan, whose subsequent discoveries would make large-scale electricity generation feasible.

1879 – Lighting becomes practical and inexpensive

Thomas Edison patented the first practical and accessible incandescent light bulb, using a carbonised bamboo filament which could burn for more than 1,200 hours. Edison made the first public demonstration of his incandescent lightbulb on 31st December 1879 where he stated that, “electricity would be so cheap that only the rich would burn candles.” Although he was not the only inventor to experiment with incandescent light, his was the most enduring and practical. He would soon go on to develop not only the bulb, but an entire electrical lighting system.

Holborn Viaduct power station via Wikimedia

1882 – The world’s first public power station opens

Holborn Viaduct power station, also known as the Edison Electric Light Station, burnt coal to drive a steam turbine and generate electricity. The power was used for Holborn’s newly electrified streetlighting, an idea which would quickly spread around London.

1880s – Tesla and Edison’s current war

Nikola Tesla and Thomas Edison waged what came to be known as the current war in 1880s America. Tesla was determined to prove that alternating current (AC) – as is generated at power stations – was safe for domestic use, going against the Edison Group’s opinion that a direct current (DC) – as delivered from a battery – was safer and more reliable.

Inside an Edison power station in New York

The conflict led to years of risky demonstrations and experiments, including one where Tesla electrocuted himself in front of an audience to prove he would not be harmed. The war continued as they fought over the future of electric power generation until eventually AC won.

Nikola Tesla

1901 – Great Britain’s first industrial power station opens

Before Charles Mertz and William McLellan of Merz & McLellan built the Neptune Bank Power Station in Tyneside in 1901, individual factories were powered by private generators. By contrast, the Neptune Bank Power Station could supply reliable, cheap power to multiple factories that were connected through high-voltage transmission lines. This was the beginning of Britain’s national grid system.

1990s – The first mass market electrical vehicle (EV)

Concepts for electric cars had been around for a century, however, the General Motors EV1 was the first model to be mass produced by a major car brand – made possible with the breakthrough invention of the rechargeable battery. However, this EV1 model could not be purchased, only directly leased on a monthly contract. Because of this, its expensive build, and relatively small customer following, the model only lasted six years before General Motors crushed the majority of their cars.

2018 – Renewable generation accounts for a third of global power capacity

The International Renewable Energy Agency’s (IRENA) 2018 annual statistics revealed that renewable energy accounted for a third of global power capacity in 2018. Globally, total renewable electricity generation capacity reached 2,351 GW at the end of 2018, with hydropower accounting for almost half of that total, while wind and solar energy accounted for most of the remainder.