Tag: FAQs (frequently asked questions)

What is the carbon cycle?

25 March 2022

Carbon capture

What is the carbon cycle?

All living things contain carbon and the carbon cycle is the process through which the element continuously moves from one place in nature to another. Most carbon is stored in rock and sediment, but it’s also found in soil, oceans, and the atmosphere, and is produced by all living organisms – including plants, animals, and humans.

Carbon atoms move between the atmosphere and various storage locations, also known as reservoirs, on Earth. They do this through mechanisms such as photosynthesis, the decomposition and respiration of living organisms, and the eruption of volcanoes.

As our planet is a closed system, the overall amount of carbon doesn’t change. However, the level of carbon stored in a particular reservoir, including the atmosphere, can and does change, as does the speed at which carbon moves from one reservoir to another.

What is the role of photosynthesis in the carbon cycle?

Carbon exists in many different forms, including the colourless and odourless gas that is carbon dioxide (CO2). During photosynthesis, plants absorb light energy from the sun, water through their roots, and CO2 from the air – converting them into oxygen and glucose.

The oxygen is then released back into the air, while the carbon is stored in glucose, and used for energy by the plant to feed its stem, branches, leaves, and roots. Plants also release CO2 into the atmosphere through respiration.

Animals – including humans – who consume plants similarly digest the glucose for energy purposes. The cells in the human body then break down the glucose, with CO2 emitted as a waste product as we exhale.

CO2 is also produced when plants and animals die and are broken down by organisms such as fungi and bacteria during decomposition.

What is the fast carbon cycle?

The natural process of plants and animals releasing CO2 into the atmosphere through respiration and decomposition and plants absorbing it via photosynthesis is known as the biogenic carbon cycle. Biogenic refers to something that is produced by or originates from a living organism. This cycle also incorporates CO2 absorbed and released by the world’s oceans.

The biogenic carbon cycle is also called the “fast” carbon cycle, as the carbon that circulates through it does so comparatively quickly. There are nevertheless substantial variations within this faster cycle. Reservoir turnover times – a measure of how long the carbon remains in one location – range from years for the atmosphere to decades through to millennia for major carbon sinks on land and in the ocean.

What is the slow carbon cycle?

In some circumstances, plant and animal remains can become fossilised. This process, which takes millions of years, eventually leads to the formation of fossil fuels. Coal comes from the remains of plants that have been transformed into sedimentary rock. And we get crude oil and natural gas from plankton that once fell to the ocean floor and was, over time, buried by sediment.

The rocks and sedimentary layers where coal, crude oil, and natural gas are found form part of what is known as the geological or slow carbon cycle. From this cycle, carbon is returned to the atmosphere through, for example, volcanic eruptions and the weathering of rocks. In the slow carbon cycle, reservoir turnover times exceed 10,000 years and can stretch to millions of years.

How do humans impact the carbon cycle?

Left to its own devices, Earth can keep CO2 levels balanced, with similar amounts of CO2 released into and absorbed from the air. Carbon stored in rocks and sediment would slowly be emitted over a long period of time. However, human activity has upset this natural equilibrium.

Burning fossil fuel releases carbon that’s been sequestered in geological formations for millions of years, transferring it from the slow to the fast (biogenic) carbon cycle. This influx of fossil carbon leads to excessive levels of atmospheric CO2, that the biogenic carbon cycle can’t cope with.

As a greenhouse gas that traps heat from the sun between the Earth and its atmosphere, CO2 is essential to human existence. Without CO2 and other greenhouse gases, the planet could become too cold to sustain life.

However, the drastic increase in atmospheric CO2 due to human activity means that too much heat is now retained between Earth and the atmosphere. This has led to a continued rise in the average global temperature, a development that is part of climate change.

Where does biomass fit into the carbon cycle?

One way to help reduce fossil carbon is to replace fossil fuels with renewable energy, including sustainably sourced biomass. Feedstock for biomass energy includes plant material, wood, and forest residue – organic matter that absorbs CO2 as part of the biogenic carbon cycle. When the biomass is combusted in energy or electricity generation, the biogenic carbon stored in the organic matter is released back into the atmosphere as CO2.

This is distinctly different from the fossil carbon released by oil, gas, and coal. The addition of carbon capture and storage to bioenergy – creating BECCS – means the biogenic carbon absorbed by the organic matter is captured and sequestered, permanently removing it from the atmosphere. By capturing CO2 and transporting it to geological formations – such as porous rocks – for permanent storage, BECCS moves CO2 from the fast to the slow carbon cycle.

This is the opposite of burning fossil fuels, which takes carbon out of geological formations (the slow carbon cycle) and emits it into the atmosphere (the fast carbon cycle). Because BECCS removes more carbon than it emits, it delivers negative emissions.

Fast facts

  • According to a 2019 study, human activity including the burning of fossil fuels releases between 40 and 100 times more carbon every year than all volcanic eruptions around the world.
  • In March 2021, the Mauna Loa Observatory in Hawaii reported that average CO2 in the atmosphere for that month was 14 parts per million. This was 50% higher than at the time of the Industrial Revolution (1750-1800).
  • There is an estimated 85 billion gigatonne (Gt) of carbon stored below the surface of the Earth. In comparison, just 43,500 Gt is stored on land, in oceans, and in the atmosphere.
  • Forests around the world are vital carbon sinks, absorbing around 7.6 million tonnes of CO2 every year.

Go deeper

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)?

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

18 May 2021

Carbon capture

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

Bioenergy with carbon capture and storage (BECCS) is the process of capturing and permanently storing carbon dioxide (CO2) from biomass (organic matter) energy generation.

Why is BECCS important for decarbonisation? 

When sustainable bioenergy is paired with carbon capture and storage it becomes a source of negative emissions, as CO2 is permanently removed from the carbon cycle.

Experts believe that negative emissions technologies (NETs) are crucial to helping countries meet the long-term goals set out in the Paris Climate Agreement. As BECCS is the most scalable of these technologies this decade, it has a key role to play in combating climate change.

How is the bioenergy for BECCS generated?

Most bioenergy is produced by combusting biomass as a fuel in boilers or furnaces to produce high-pressure steam that drives electricity-generating turbines. Alternatively, bioenergy generation can use a wide range of organic materials, including crops specifically planted and grown for the purpose, as well as residues from agriculture, forestry and wood products industries. Energy-dense forms of biomass, such as compressed wood pellets, enable bioenergy to be generated on a much larger scale. Fuels like wood pellets can also be used as a substitute for coal in existing power stations.

How is the carbon captured?

BECCS uses a post-combustion carbon capture process, where solvents isolate CO2 from the flue gases produced when the biomass is combusted. The captured CO2 is pressurised and turned into a liquid-like substance so it can then be transported by pipeline.

How is the carbon stored?

Captured CO2 can be safely and permanently injected into naturally occurring porous rock formations, for example unused natural gas reservoirs, coal beds that can’t be mined, or saline aquifers (water permeable rocks saturated with salt water). This process is known as sequestration.

Over time, the sequestered CO2 may react with the minerals, locking it chemically into the surrounding rock through a process called mineral storage.

BECCS fast facts

  • Two 600+ megawatt (MW) biomass units, upgraded with carbon capture technology, could deliver 40% of the negative emissions the Climate Change Committee indicates will be needed from BECCS for the UK to reach net-zero by 2050
  • BECCS has the potential to remove 20-70 million tonnes of CO2 per year in the UK by 2050
  • All National Grid’s Net Zero Future Energy Scenarios (FES) deploy BECCS by 2028 and see a rapid increase in capacity in the 2030s
  • There are 70 billion tonnes of potential CO2 storage space around the UK, according to the British Geological Survey

Is BECCS sustainable?

 Bioenergy can be generated from a range of biomass sources ranging from agricultural by-products to forestry residues to organic municipal waste. During their lifetime plants absorb CO2 from the atmosphere, this balances out the CO2that is released when the biomass is combusted.

What’s crucial is that the biomass is sustainably sourced, be it from agriculture or forest waste. Responsibly managed sources of biomass are those which naturally regenerate or are replanted and regrown, where there’s a increase of carbon stored in the land and where the natural environment is protected from harm.

Biomass wood pellets used as bioenergy in the UK, for example, are only sustainable when the forests they are sourced from continue to grow. Sourcing decisions must be based on science and not adversely affect the long-term potential of forests to store and sequester carbon.

Biomass pellets can also create a sustainable market for forestry products, which serves to encourage reforestation and afforestation – leading to even more CO2 being absorbed from the atmosphere.

Go deeper:

  • The triple benefits for the environment and economy of deploying BECCS in the UK.
  • How BECCS can offer essential grid stability as the electricity system moves to low- and zero-carbon sources.
  • Producing biomass from sustainable forests is key to ensuring BECCS can deliver negative emissions.
  • 5 innovative projects where carbon capture is already underway around the world
  • 7 places on the path to negative emissions through BECCS

What is carbon dioxide?

18 September 2020

Carbon capture

What is CO2?

Carbon dioxide (or CO2) is a colourless and odourless naturally occurring gas in the earth’s atmosphere which is made up of one carbon atom and two oxygen atoms.  As a greenhouse gas (GHG), it traps heat, making sure the planet isn’t uninhabitably cold. However, fast rising levels of CO2 and other long-lasting GHGs in the atmosphere are currently causing global warming to occur at an alarmingly rapid rate.

What is the carbon cycle?

Carbon is the basis of all life on earth – it is a key ingredient in almost everything on the planet. As the earth has a closed atmosphere, there has always been the same amount of carbon on the earth, but it is in a constant state of change, transitioning from gas to solid to liquid and moving between the atmosphere and the earth. This process is called the carbon cycle, and it is key to ensuring the earth is capable of sustaining life. CO2 forms one part of this process and makes up the largest available source of carbon on earth.

How is CO2 made?

Carbon is stored in oceans, soil, and living things and is released from this storage into the atmosphere in the form of CO2. CO2 is created when one carbon atom meets two oxygen atoms, which join together through a number of processes, including the decay of organic matter, the combustion of materials such as wood, coal and natural gas, through the breathing of humans and animals, and from events such as volcanic eruptions.

How does CO2 affect the planet?

An abundance of CO2 in the earth’s atmosphere means more heat gets trapped, which in turn contributes to a rise in global temperatures and climate change. This acceleration in carbon entering the atmosphere began during the Industrial Revolution around the 1800s, when fossil fuels were mined and burned to create energy, which released long-stored carbon into the atmosphere in the form of CO2.

From the beginning of the Industrial Revolution until today, the amount of carbon in the atmosphere has increased from 280 parts per million, to 387 parts per million, which constitutes a 39% increase. Today, CO2 levels are the highest they’ve been in 800,000 years.

CO2 is created when one carbon atom meets two oxygen atoms, which join together when organic materials containing carbon are burned: wood, coal, and natural gas.

How can countries reduce CO2 in the atmosphere?

According to the Paris Climate Agreement, nations must work to limit warming of the globe to be well under two degrees Celsius above pre-industrial levels. In the first half of 2015, the earth registered a one degree Celsius rise in global temperatures above pre-industrial levels, which means drastic and meaningful action must be taken to decarbonise within the next few years.

There are many ways to reduce the earth’s carbon footprint, including reforestation and using alternative ways to generate energy that don’t rely on fossil fuels. For example, wind, solar, biomass and hydro can all provide sustainable, carbon-neutral and low carbon sources of electricity.

Technology such as carbon capture and storage (CCS) can capture carbon permanently storing CO2 from industries in which some CO2 emissions remain. By combining CCUS with biomass energy (bioenergy with carbon capture and storage, or BECCS) it is even possible to generate negative emissions, where more CO2 is removed from the atmosphere than is emitted.

CO2 fast facts

  • In the 1960s, the growth of CO2 occurred at 0.6 parts per million per year. In the last 10 years, the rate has been 2.3 parts per million per year
  • The average human breathes out 93 kilograms of CO2 per year – however, our breathing only contributes 0.65 billion tonnes of carbon returned to the atmosphere, which is 0.01% of the amount released by fossil fuels each year
  • Trees absorb CO2 in the atmosphere and release it in the form of oxygen, making them vitally important in the world’s fight against climate change. In the US alone, forests absorb 13% of the nation’s carbon output

There are many ways to reduce the earth’s carbon footprint, including using alternative ways to generate power.

Go deeper

 

What is biomass?

21 August 2020

Sustainable bioenergy
Illustration of a working forest supplying biomass

What is biomass?

In ecological terms, biomass refers to any type of organic matter. When it comes to energy, biomass is any organic matter that can be used to generate energy, for example wood, forest residues or plant materials.

How is biomass used?  

Biomass used and combusted for energy can come in a number of different forms, ranging from compressed wood pellets – which are used in power stations that have upgraded from coal – to biogas and biofuels, a liquid fuel that can be used to replace fossil fuels in transport.

The term biomass also refers to any type of organic material used for energy in domestic settings, for example wood burned in wood stoves and wood pellets used in domestic biomass boilers.

Biomass is organic matter like wood, forest residues or plant material, that is used to generate energy.

Where does biomass come from?

Biomass can be produced from different sources including agricultural or forestry residues, dedicated energy crops or waste products such as uneaten food.

Drax Power Station uses compressed wood pellets sourced from sustainably managed working forests in the US, Canada, Europe and Brazil, and are largely made up of low-grade wood produced as a byproduct of the production and processing of higher value wood products, like lumber and furniture.

Biomass producers and users must meet a range of stringent measures for their biomass to be certified as sustainable and responsibly sourced.

Key biomass facts

Is biomass renewable?

 Biomass grown through sustainable means is classified as a renewable source of energy because of the process of its growth. As biomass comes from organic, living matter, it grows naturally, absorbing carbon dioxide (CO2) from the atmosphere in the process.

It means when biomass is combusted as a source of energy – for example for heat or electricity production – the CO2 released is offset by the amount of CO2 it absorbed from the atmosphere while it was growing.

Fast facts

  • In 2019 biomass accounted for 6% of Great Britain’s electricity generation, more than 1/6 of the total generation of all renewable sources
  • There is about 550 gigatonnes of biomass carbon on Earth in total. Humans make up around 1/10,000th of that mass.
  • Modern biomass was first developed as an alternative for oil after its price spiked as a result of the 1973 Yom Kippur War
  • The International Energy Agency (IEA) estimates bioenergy accounts for roughly 1/10th of the world’s total energy supply

Biomass is a renewable, sustainable form of energy used around the world.

How long has biomass been used as a source of energy?

Biomass has been used as a source of energy for as long as humans have been creating fire. Early humans using wood, plants or animal dung to make fire were all creating biomass energy.

Today biomass in the form of wood and wood products remains a widely used energy source for many countries around the world – both for domestic consumption and at grid scale through power stations, where it’s often used to replace fossil fuels with much higher lifecycle carbon emissions.

Drax Power Station has been using compressed wood pellets (a form of biomass) since 2003, when it began research and development work co-firing it with coal. It fully converted its first full generating unit to run only on compressed wood pellets in 2013, lowering the carbon footprint of the electricity it produced by more than 80% across the renewable fuel’s lifecycle. Today the power station runs mostly on sustainable biomass.

Go deeper

Read next: What is reforestation and afforestation?

What is carbon capture usage and storage?

Carbon capture
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

Go deeper

 

Button: What are negative emissions?

What is climate change?

Sustainable business
Climate change

What is climate change?

Climate change refers to the change in weather patterns and global temperature of the earth over long periods of time. In a modern context, climate change describes the rise of global temperatures that has been occurring since the Industrial Revolution in the 1800s.

What causes climate change?

While there have been natural fluctuations in the earth’s climate over previous millennia, scientists have found that current-day temperatures are rising quicker than ever due to the excessive amount of carbon dioxide (CO2) and other greenhouse gasses being released into the atmosphere.

Key climate crisis facts

An excess of CO2 in the atmosphere accentuates something called the ‘greenhouse effect’. As CO2 traps heat in the earth’s atmosphere, it warms the planet and causes a rise in average global temperature. International efforts, such as the Paris Climate Accords, are dedicated to ensuring temperatures do not rise 2 degrees Celsius above pre-industrial levels, which could lead to catastrophic conditions on the planet.

In the modern context, climate change describes the rise of global temperatures occurring since the Industrial Revolution in the 1800s.

How do humans contribute to climate change?  

Industries such as transport, agriculture, energy and manufacturing have traditionally relied on the use of coal, oil and other fossil fuels. These fuels, when combusted or used, emit large amounts of CO2 into the atmosphere, further advancing the greenhouse effect and contributing to climate change.

Human reliance and consumption of these products mean today CO2 levels are the highest they’ve been in 800,000 years.

Why are rising temperatures harmful to the planet?

Our planet has a history of experiencing periods of extreme weather conditions – for example the last Ice Age, which finished 12,000 years ago. However, the rapid rise in temperatures seen today is harmful because a hotter planet completely affects our natural environment.

A steep rise in global temperature can melt ice sheets and cause higher sea levels which can, in turn, contribute to more extreme storms and even threaten entire islands and coastal communities. As the planet warms, extreme weather events, such as bushfires could become more common, which can destroy homes, impact agriculture and degrade air quality, while entire ecosystems, habitats and animal and insect species could also be threatened by climate change. 

What can be done to mitigate the effects of climate change?

Reducing CO2 emissions is a key way of slowing down the pace of climate change. To do so, industries across the global economy must decarbonise to become less dependent on fossil fuels, such as coal and petrol, and adopt new lower carbon energy sources.

Decarbonisation will rely on a number of factors, including a technological response that sees the development and implementation of carbon neutral and carbon negative ways of creating heat, electricity and fuels, including the use of innovations such as carbon capture and storage (CCS).

There is also a need for a policy and governmental response that promotes investment in new cleaner technologies and disincentivises dirtier industries through mechanisms like the carbon tax. Countries and economies will need to work collaboratively to achieve common, climate-oriented goals that will also enable smaller scale action to be taken by individuals around the world. 

Go deeper

Button: What is the grid?

What are ancillary services?

Power generation
Ancillary services

What are ancillary services?

Ancillary services are a set of processes that enable the transportation of electricity around the grid while keeping the power system operating in a stable, efficient and safe way.

Why do we need ancillary services? 

When electricity makes its way through the country, it needs to be managed so that the power generation and electricity useage levels are equal.

The regulating of elements such as frequency and voltage has to be carefully managed, so that the massive amounts of electricity moving – or transmitted – are able to be used safely in homes,  businesses, schools and hospitals around the country.

Ancillary services enable the power system to operate in a stable, efficient and safe way.

 What do ancillary services offer?

Ancillary services include a wide variety of electrical efficiency and safety nets, all focussed on ensuring the power system delivers enough output to meet demand yet remains stable:

Frequency: The UK’s power system runs at a frequency of 50 hertz – to stay balanced, it has to remain at that frequency. Turbines and generators adjust the speed at which they spin automatically to increase or decrease power in line with demand and ensure that the system is kept stable.

Voltage: Different parts of the UK’s transmission system use voltages of either 400, 275 or 132 kilovolts. To ensure that voltage remains within 5% of those figures at all times, to be safe for domestic electricity use, power stations can produce or re-absorb excess energy as reactive power, keeping the overall system reliable.

Inertia: Turbine use is important in keeping the system operating in its current state, even with disruptions and sudden changes. The electricity system uses the weight of heavy spinning turbines to create stability, acting as dampeners and smoothing out unexpected changes in frequency across the network.

Reserve: An important part of ancillary servicing is making sure that there are no surprises – so holding back powerto release if something unexpected happens means that the network can function confidently, knowing that there are generators and other power providers such as pumped hydro storage waiting ready to back it up.

Key facts about ancillary services

Who manages ancillary services?

In the UK the grid’s stability is managed by National Grid Electricity System Operator (ESO) – a  separate company of National Grid Electricity Transmission (ET). The ESO works with ancillary service providers to either sign long-term contracts or make short term requests for a service.

These partners are often power stations, such as Drax Power Station, which have large spinning turbines capable of controlling voltage, frequency, providing inertia and serving as a source of reserve power. 

What is the future of ancillary services, as we move to a more renewable system?

As the UK’s electricity system continues to change, so to do its requirements for different ancillary services. The switch from a few very large power stations to a greater variety of different electricity sources, some of which may be dependent on the weather, as well as changes in how the country uses electricity, means there is a greater need for ancillary services to keep the grid stable.

These services have historically been delivered by thermal power stations, but new innovations are enabling wind turbines to provide inertial response and overcome changes in frequency, and batteries to store reserve power that can then be supplied to the power system to ensure balance.

Ancillary Services

Ancillary services fast facts  

  • Batteries can in some cases be cheaper ancillary alternatives to conventional sources of energy. The Hornsdale Power Reserve, which runs on a Tesla battery in South Australia, lowered the price of frequency ancillary services by 90% after just four months of use.
  • Ancillary services usually work from habit; knowing when to slow electricity production, or increase supply based around the general public’s standard working hours, dinner time and the early morning rush.
  • But during the COVID-19 lockdown, electricity consumption on weekdays fell by 13% and so National Grid ESO had to intervene with ancillary services to keep the lights on.
  • Every year, the ESO’s ancillary services move 300 terawatt hours (TWh) of electricity, which is equal to 4 trillion kettles boiling at once.

With recent innovations around renewable energies, there are a wider variety of ways for ancillary services to generate power.

Go deeper

Button: What is decarbonisation?

What is decarbonisation?

Carbon capture
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

Go deeper

Button: What is biomass?