Tag: decarbonisation

Capturing carbon emissions from the atmosphere could transform these industries

24 April 2019

Carbon capture

Countries, companies and industries around the world are racing to find ways to reduce their emissions. But looking slightly further down the line there is in fact a grander aim: negative emissions.

Negative emissions technologies (NETs) can actually absorb more carbon dioxide (CO2) from the atmosphere than they emit, and they’re vitally important for avoiding catastrophic, man-made climate change. Without NETs it could be impossible to achieve the Intergovernmental Panel on Climate Change’s ambition of keeping temperatures under 1.5 degrees Celsius above pre-industrial levels.

One example already being implemented is bioenergy with carbon capture and storage (BECCS). It is what its name suggests. Using technologies to capture and store the CO2 generated during the process of energy generation from biomass or organic materials rather than releasing it into the atmosphere.

BECCS holds vast potential in the electricity generation industry. Drax Power Station is currently piloting one form of this technology on one of its biomass units to capture as much as a tonne of CO2 a day. But if it were deployed across all its biomass units, BECCS technology could make it the world’s first negative emissions power station.

Beyond the power industry, however, there’s scope for growth across other industries once the biomass is sourced sustainably. There are already five sites around the world where BECCS is being trialled and implemented at scale, laying the road to negative emissions.

Storing CO2 from ethanol production in the Illinois Basin

The ethanol production industry is already seeing significant deployment of BECCS, including the largest installation of the technology operating in the world. The Illinois Industrial Carbon Capture and Storage project is part of a corn-to-ethanol plant in the US that has the capacity to capture 1 million tonnes of CO2 every year.

Here, corn is used to create ethanol by fermenting it in an oxygen-deprived environment. This process creates CO2 as a by-product, which is captured and stored permanently in pores within the sandstone of the Illinois Basin under the facility.

Researchers believe with further development the site could capture as much as 250 million tonnes each year.

Norway’s cement challenge  

Concrete is one of the world’s most versatile building materials. As a result it is the second most-consumed material in the world behind water – more than 10 billion tonnes of it is produced every year. However, its key ingredient – cement, which acts as concrete’s binding agent – is made using a hugely carbon-intensive manufacturing process and now accounts for as much as 6% of all global carbon emissions.

The Norcem Cement plant in Brevik, South-East Norway, has been experimenting with using biomass to power the kilns used to create its cement (which must heat ingredients to 1,500 degrees Celsius). Now it’s taking this a step further by becoming part of the country’s ambitious Full Chain CCS project.

The project will see 400,000 tonnes of CO2 captured annually, which will then be transported by ship to a storage site on Norway’s western coast. From here a pipeline will transport the CO2 50 kilometres away and deposit it deep below the North Sea’s bed.

The plan has the potential to work at an even bigger scale. The pipeline will be capable of receiving as much as 4 million tonnes of CO2 per year, meaning it could even import and store carbon from other countries.

Burning waste and growing algae

In a world that seems increasingly unsure how to safely deal with its waste, the idea of incinerating it and making use of the heat this produces seems widely beneficial. But combusting any solid means releasing carbon emissions.

In Japan, however, a biomass-fired waste incineration plant is changing this by being the first in the world to capture its carbon emissions.

To get this project up and running, Toshiba, the firm behind the project, had to overcome unique challenges. For example, waste incineration produces a greater mix of chemicals than in ethanol or power production, including some that are corrosive to the metal pipes normally used in carbon capture.

Now running at commercial scale, the Saga City waste incineration plant isn’t just capturing CO2, it’s also utilising it to cultivate crops at a nearby algae farm. The carbon is being absorbed and used to grow algae for use in commercial scale cosmetic products, such as body and skin lotions.

Carbon isn’t the only thing finding new use at the facility. Reconstituted scrap metal from the plant is being used to make the medals for the 2020 Tokyo Olympics.

The carbon capture system has been operational since 2016 and is capable of capturing 3,000 tonnes of CO2 a year, but it isn’t the region’s first deployments of BECCS. 

Fully integrating BECCS into biomass power

Nearby, the Mikawa power plant on the Fukuoka Prefecture, is leading the race in Asia to fully integrate carbon capture technology into a biomass power station.

The 50 MW power station successfully piloted carbon capture in 2009 through a partnership with Toshiba. At the time it was powered by coal, however, in 2017, the plant upgraded to a 100% biomass boiler fuelled by palm kernel shells – a waste product from palm oil extraction mills. Now it’s in the process of ramping up its carbon capture capabilities, with a target of being operational in 2020.

The system – which after Drax will be the second plant in the world to capture carbon using 100% biomass feedstock – will have the capacity to capture more than 50% of the biomass plant’s CO2 emissions, or as much as 180,000 tonnes per year. Japan’s government is now supporting efforts to develop CO2 transportation and potential offshore storage solutions for next year.

Pulping wood and growing food

BECCS technology has yet to be deployed in the paper industry to the same extent as in other organic-matter-based industries. But with many pulp and paper mills already using by-products, such as hog fuel, in generating power for their sites, it’s a prime area for BECCS growth.

In Saint-Felicien, Quebec, commercial-scale carbon capture technology is being deployed at a pulp mill run by Resolute Forest Products, and, as of March 2019, had a capacity of capturing 11,000 tonnes of CO2 a year. Rather than storage, however, it supplies the carbon to a cucumber-growing greenhouse next door to the mill, as well as supplying enough warm water to meet 25% of the greenhouses’ heating needs.

Both long established biomass-based industries like ethanol and paper, and new sectors like electricity, are now adopting BECCS technology and driving innovation.

The biomass feedstocks involved in BECCS must, however, be sourced sustainably – or else a positive climate impact could be at the expense of environmental degradation elsewhere. ‘It should be possible to expand biomass supply in a sustainable way,’ found a recent ‘Global biomass markets’ report from Ricardo AEA for the UK’s Department for Business, Energy and Industrial Strategy (BEIS).

While it’s still a complex technology to deploy, BECCS is increasingly operating at larger scales and growing to the level needed to seriously reduce industrial CO2 emissions and help to combat climate change.

Learn more about carbon capture, usage and storage in our series:

Heating the future

9 April 2019

Sustainable bioenergy

We all want our homes and our workplaces to be warm and cosy, but not at the cost of catastrophic climate change. That’s why decarbonising our heating is a challenge that simply cannot be ignored.

Making decisions about how this is done requires careful consideration and a detailed, deliverable national strategy.

Here we discuss the key issues in decarbonising heat.

The numbers

The Climate Change Act commits the UK to reducing its carbon emissions by at least 80 per cent of their 1990 levels by 2050.

As heating our homes and workplaces is responsible for almost one fifth of our country’s total carbon emissions, we are clearly going to need to make huge changes to the way we keep our homes and workplaces warm in order to meet those commitments.

‘Over 80% of energy used in homes is for heating – suggesting large potential for continued decarbonisation.’

— Energising Britain: Progress, impacts and outlook for transforming Britain’s energy system, by I. Staffell, M. Jansen, A. Chase, C. Lewis and E. Cotton, 2018.

Improved insulation, greater energy efficiency and electrification will all reduce the need for fossil fuel-based heating. However, domestic energy efficiency in the UK is lagging well behind targets, although the situation varies from region to region – and such targets do not even exist yet for the non-domestic sector.

Roof insulation material

Even in a low or zero-carbon future, we’re still going to need to keep our homes and workplaces warm – and affordably.

Future policy

Against this backdrop, in March 2018, the UK Government issued a call for evidence for a Future Framework for Heat in Buildings.

Chancellor Phillip Hammond introduced a new ‘future homes standard’ in his 2019 Spring Budget Statement, “mandating the end of fossil fuel heating systems.” Gas boilers will be banned from all new homes from 2025.

A major change is coming. But what else will we need to change in order to transform our heating systems?

1. More electrification

The most noticeable change in the way we heat our homes and workspaces in the future may well come from the need to switch from systems that fuelled by natural gas to ones that are driven by electricity.

Some technologies that can offer a solution to the challenge of decarbonising heating depend on a significant amount of electricity to keep the warmth flowing.

For instance, the hybrid heat pump scenario which is currently supported by the Committee on Climate Change would see up to 85% of a consumer’s need for heat being met by low-carbon electricity.

To give some context to that figure, according to the Committee, 85 per cent of the UK’s homes now rely on fossil-fuel derived natural gas for heating and hot water, and on average these: “currently emit around 2tCO2 per household per year… which represents around one tenth of the average UK household’s carbon footprint.”

Changing from a situation where our heating depends on 85% fossil fuel gas to one that depends on 85% low or zero carbon electricity is little short of a complete transformation. Given that the new future homes standard is due to be introduced in less than six years, this transformation will need to happen quickly.

Of course, a great deal of the extra electricity needed will come from intermittent renewables such as wind turbines and solar panels – especially as the cost of renewable electricity is falling.

Much of that power looks likely to be supplied by distributed sources rather than those integrated into the national grid. Indeed, since 2011, power generation capacity connected directly to the distribution network grew from 12 gigawatts (GW) to more than 40 GW by the end of 2017, according to estimates from energy experts Cornwall Insight in a report for our B2B energy supply business, Haven Power.

With so much of our electricity reliant on the weather, there will still be a need for dispatchable and flexible thermal sources and energy storage, such as Drax and Cruachan power stations. Their centralised power generation can be turned up and fed directly into the national transmission system at short notice, to keep our heating running and our homes warm.

Dam and reservoir, Cruachan Power Station, Scotland

Such a transformation will obviously require careful strategic planning as well as an enormous amount of investment.

There may well be no single solution to the challenge of heat decarbonisation, rather a number of different solutions that depend on where people live and work, their individual circumstances, the energy efficiency of their homes and the resources they have close at hand.

But while it has previously been reported that the overall or system costs of electrifying heating could be as much as three times the cost of using gas, another study suggests that the costs could be much closer.

2. More heat pumps

Heat pumps that absorb environmental warmth and use it to provide low carbon heating have always been considered a possible option for the four million homes and countless workplaces that are not currently connected to the UK’s mains gas network.

Recently expert opinion has been changing with hybrid heat pumps seen as a workable solution even for homes and workplaces that are connected to gas supplies. Indeed, in 2018 the Committee on Climate Change stated that hybrid heat pumps: “can be the lowest cost option where homes are sufficiently insulated, or can be insulated affordably.” This means that they may be one of the simplest and most affordable options to provide the heating of the future.

Hybrid heat pumps draw heat from the air or ground around them and use a boiler to provide extra heat when the weather is exceptionally cold. In a low carbon future, that boiler could be fuelled by biogas. In a zero carbon situation, it could be powered by hydrogen.

Heat pumps can be air-source (ASHP) – absorbing warmth from the atmosphere like the heat exchanger in your fridge in reverse – or ground source (GSHP). GSHPs absorb heat through on a network of pipes (a ground loop) buried or a vertical borehole drilled in the earth outside your home or workplace.

Both ASHPs and GSHPs can be used to support underfloor heating or a radiator system, though neither will provide water heated to the high temperature a natural gas boiler will reach to keep radiators hot.

And even though the warmth they absorb is free, heat pumps depend on a supply of electricity to condense it and to bring it back to the heating system inside the house.

This electricity could be generated by distributed power from local solar PV, wind turbines, drawn from batteries or even from the low carbon grid of the future.

It is worth noting that the size of heat pumps and the amount of land they require – especially GSHP – makes them a less attractive solution for people who live or work in built up areas such as cities. While for those who live in blocks of flats, it is difficult to see how individual heat pumps could be a practical solution.

3. More hydrogen

The idea of switching the mains gas grid to store and transport hydrogen has long appealed as a potential solution to the challenge of decarbonising heating. Renewable hydrogen could then be burnt in domestic boilers similar to those we currently use for natural gas.

The benefits are many. Hydrogen produces no carbon emissions when burnt, and can be stored and transported in much the same way as natural gas (provided old metal pipes have been replaced with modern alternatives).

And given the sunk costs involved in the existing gas grid and in the network of pipes and radiators already installed in tens of millions of homes, hydrogen has always been expected to be the lowest cost option too.

However, according to the Committee on Climate Change’s latest findings, hydrogen should not be seen as a ‘silver bullet’ solution, capable of transforming our entire heating landscape in a single change.

The main reasons they give for this judgment are the relatively high cost of the electricity required to produce sufficient hydrogen to power tens of millions of boilers, the undesirability of relying on substantial imports of hydrogen, and the lack of a carbon-free method to supply the gas cost-effectively at scale.

Hydrogen could, however, be produced by gas reformation of the emissions retained by bioenergy carbon capture and storage (BECCS) such as that being pioneered at Drax Power Station. Carbon capture use and storage (CCUS), of which BECCS is the renewable variant, is supported by the UK government through its Clean Growth Strategy as it has potential to accelerate decarbonisation in power and industrial sectors.

Extremely rapid progress to provide hydrogen in sufficient quantities from BECCS is unlikely – but the first schemes could begin operating in the late 2020s.

Hydrogen production also has the potential to radically transform the economics of CCUS, making it a much more attractive investment.

It was originally assumed that the power required to drive the energy-intensive process of hydrogen created via electrolysis would come from surplus electricity generated by intermittent renewables at times of low demand. However, that surplus is not now generally regarded as likely to be sufficiently large to be relied upon. 

It is these limitations, together with a comprehensive model of the likely costs involved in different approaches to decarbonisation, that led the Committee on Climate Change to suggest that hybrid heat pumps could provide the bulk of domestic heating in the future.

At present, it seems likely that converting to hydrogen-fuelled boilers will mainly be an attractive option for those who live and work near areas where the renewable fuel can be most easily created and stored. The north of England is a prime example – close to the energy and carbon intensive areas of the Humber and Tees valleys where CCUS and hydrogen clusters could be located with good access to North Sea carbon stores such as aquifers and former gas fields.

4. More solar

Many homes in the UK – especially in the south – could be heated electrically without carbon emissions at the point of use.

Solar thermal (for water heating) or solar PVs (for electric and water heating) common sights on domestic property rooftops. The intermittency of solar power need not be an issue as the electricity generated could then be stored in batteries ‘behind the meter’ until it is needed.

However, the lack of sufficient daylight for much of the year in many parts of the UK could, together with the still relatively high cost of battery storage, still mean that this would not necessarily be a solution that can be applied at scale to millions of homes and workplaces all year round.

As the cost of battery storage continues to fall, it may well be that solar becomes a more practical and cost-effective solution.

5. More biomass

More geothermal

Sustainably sourced compressed wood pellets and biomass boilers have long been proposed as a potential solution to decarbonising heating for the many people who live and work off the mains gas grid. Bioenergy as a whole – including biogas as well as wood pellets – now provides around four percent of UK heat, up from 1.4% in 2008.

The main barriers to this are the current relatively high cost of biomass boilers. This is currently offset by the Renewable Heating Incentive (RHI) which the UK government has committed to continuing until 2021.

As this solution is adopted by more consumers, it is anticipated that the real costs of such new technology will fall as economies of scale start to take effect in much the same way that solar PV and battery technology has recently become more affordable.

6. More geothermal

Ruins of a tin mine, Wheal Coates Mine, St. Agnes, Cornwall, England

Geothermal energy uses the heat stored beneath the surface of our planet itself to provide the energy we need.

While in some countries such as Iceland, geothermal energy is used to drive turbines to generate electricity that is then used to provide power for heating, it is envisaged that in the UK it could be converted into warmth through massive heat pumps that provide heating to entire communities – especially those in former mining areas. There is already one geothermal district heating scheme in operation in the UK, in Southampton.

It is envisaged that such geothermal schemes would work most effectively at a district level, providing zero carbon heat to many homes and workplaces. According to a recent report, geothermal energy has the potential to “produce up to 20 per cent of UK electricity and heat for millions.”

At present, drilling is being carried out to see if geothermal heating could be viable in Cornwall. However, there is no reason why it could not be used in disused coalmines too where ground source heat pumps (GSHPs) would absorb and condense the required heat. This means that geothermal could have strong potential as a solution to the challenge of decarbonisation for former mining communities.

7. More CHP

By using the heat created in thermal renewable electricity generation – such as biomass – in combined heat and power schemes, businesses and individuals can reduce their energy costs and their carbon emissions. Such schemes can work well for new developments on a district basis, and are already popular in mainland Europe, especially Sweden, Denmark and Switzerland.

Warm homes, factories and offices

There are already a number of viable solutions to decarbonising heating in the UK. They rely on smart policy, smarter technology and customers taking control of their energy.

Rather than any one of these technologies providing a single solution that can help every consumer and business in the country to meet the challenge in the same way, it is more likely that it will be met by a number of different solutions, depending on geography, cost and individual circumstances. These will sometimes also work in concert rather than alone.

The UK has made solid progress on reducing carbon emissions – especially in power generation. When it comes to heating buildings, rapid decarbonisation is now needed. And that decarbonisation must avoid fuel poverty and help to rebalance the economy.

Find out more about energy in buildings in Energising Britain: Progress, impacts and outlook for transforming Britain’s energy system.

Can Great Britain keep breaking renewable records?

15 February 2019

Power generation

How low carbon can Britain’s electricity go? As low as zero carbon still seems a long way off but  every year records continue to be broken for all types of renewable electricity. 2018 was no different.

Over the full 12-month period, 53% of all Britain’s electricity was produced from low carbon sources, which includes both renewable and nuclear generation, up from 50% in 2017.  The increase in low carbon shoved fossil fuel generation down to just 47% of the country’s overall mix.

The findings come from Electric Insights, a quarterly report commissioned by Drax and written by researchers from Imperial College London.

The report found electricity’s average carbon intensity fell 8% to 217 grams of carbon dioxide per kilowatt-hour of electricity generated (g/kWh), and while this continues an ongoing decline that keeps the country on track to meet the Committee on Climate Change’s target of 100 g/kWh by 2030, it was, however, the slowest rate of decline since 2013.

It also highlights that while Britain can continue to decarbonise in 2019, the challenges of the years ahead will make it tougher to continue to break the records it has over the past few years.

The highs and lows of 2018

Last year, every type of renewable record that could be broken, was broken. Wind, solar and biomass all set new 10-year highs for respective annual, monthly and daily generation, as well as records for instantaneous output (generation over a half-hour period) and share of the electricity mix. The result was a new instantaneous generation high of 21 gigawatts (GW) for renewables, 58% of total output.

Wind had a particularly good year of renewable record-setting. It broke the 15 GW barrier for instantaneous output for the first time and accounted for 48% of total generation during a half hour period at 5am on 18 December.

Overall low carbon generation, which takes into account renewables and nuclear (both that generated in Britain and imported from French reactors), had an equally record-breaking year with an average of almost 18 GW across the full year and a new record for instantaneous output of 30 GW at 1pm on 14 June – nearly 90% of total generation over the half hour period.

While low carbon and individual renewable electricity sources hit record highs, there were also some milestone lows. Coal accounted for an average of just 5% of electricity output over the year, hitting a record low in June, when it made up just 1% of that month’s total generation. Fossil fuel output overall had a similarly significant decline, hitting a decade-low of 15 GW on average for 2018 – 44% of total generation over the year.

One fossil fuel that bucked the trend, however, was gas, which hit an all-time output of 27 GW for instantaneous generation on the night of 26 January. There was low wind on that day last year, plus much of the nuclear fleet was out of action for reactor maintenance. In one case, with seaweed clogging a cooling system.

This was all aided by an ongoing decline in overall demand as ever smarter and more efficient devices helped the country reach the decade’s lowest annual average demand of 33.5 GW. More impressive when considering how much the country’s electricity system has changed over the last decade, however, is the record low demand net of wind and solar. Only 9.9 GW was needed from other energy technologies at 4am on 14 June.

How the generation mix has changed

The most remarkable change in Britain’s electricity mix has been how far out of favour coal has fallen. From its position as the primary source from 2012 to 2014, in the space of four years it has crashed down to sixth in the mix with nuclear, wind, imports, biomass and gas all playing bigger roles in the system.

 

This sudden decline in 2015 was the result of the carbon price nearly doubling from £9.54 to £18.08 per tonne of carbon dioxide (CO2) in April, making profitable coal power stations loss-making overnight. With coal continuing to crash out of the mix, biomass has become the most-used solid fuel in Britain’s electricity system.

Interconnectors are also playing a more significant part in Britain’s electricity mix since their introduction to the capacity market in 2015. Thanks to increased interconnection to Europe, Britain is now a net importer of electricity, with 22 TWh brought in from Europe in 2018 – nine times more than it exported.

While more of Britain’s electricity comes from underwater power lines, less of it is being generated by water itself. Hydro’s decline from the fifth largest source of electricity to the eighth is the most noticeable shift outside coal’s slide. New large-scale hydro installations are expensive and a secondary focus for the government compared with cheaper renewables.

Hydro’s role in the electricity mix is also affected by drier, hotter summers, which means lower water levels. For solar, by contrast, the warmer weather will see it play a bigger role and it’s expected to overtake coal in either 2019 or 2020.

What is unlikely to change in the near-future, however, is the position at the top. In 2018 gas generated 115 TWh – more than nuclear and wind combined. But this is just one constant in a future of multiple moving and uncertain parts.

2019: a year of unpredictability

Britain is on course to leave the EU on 29 March. The effects this will have on the electricity system are still unknown, but one influential factor could be Britain’s exit from the Emissions Trading Scheme (ETS), the EU-wide market which sets prices of carbon emitted by generators. This may mean that rather than paying a carbon price on top of the ETS, as is currently the case, Britain’s generators will only have to pay the new, fixed carbon tax of £16 per tonne the UK government says will come into play in April, topped up by the carbon price support (CPS) of £18/tonne.

Lower prices for carbon relative to the fluctuating ETS + CPS, could make coal suddenly economically viable again. The black stuff could potentially become cheaper than other power sources. This about-turn could cause the carbon intensity of electricity generation to bounce up again in one or more years between 2019 and 2025, the date all coal power units will have been decommissioned.

The knock-on effect of lower carbon prices, combined with fluctuations in the Pound against the Euro, could see a reverse from imports to exports as Britain pumps its cheap, potentially coal-generated, electricity over to its European neighbours. That’s if the interconnectors can continue to function as efficiently as they do at present, which some parties believe won’t be the case if human traders have to replace the automatic trading systems currently in place.

Sizewell B Nuclear Power Station

A reversal of importing to exporting could also reduce the amount of nuclear electricity coming into the country from France. Future nuclear generation in Britain also looks in doubt with Toshiba and Hitachi’s decisions to shelve their respective plans for new nuclear reactors, which could leave a 9 GW hole in the low-carbon base capacity that nuclear normally provides.

Renewables have the potential to fill the gap and become an even bigger part of the electricity system, but this will require a push for new installations. 2018 saw a 60% drop in new wind and solar installations and less than 2 GW of new renewable capacity came onto the system, making it the slowest year for renewable growth since 2010.

Britain’s electricity has seen significant change over the last decade and 2018 once again saw the country take significant strides towards a low carbon future, but challenges lie ahead. Records might be harder to break, but it is important the momentum continues to move towards renewable, sustainable electricity.

Explore the quarter’s data in detail by visiting ElectricInsights.co.uk. Read the full report.

Commissioned by Drax, Electric Insights is produced, independently, by a team of academics from Imperial College London, led by Dr Iain Staffell and facilitated by the College’s consultancy company – Imperial Consultants.

Electricity and magnetism: the relationship that makes the modern world work

30 January 2019

Power generation

Locked in a Parisian vault and stored in a double set of bell jars is a small cylinder of metal. Made of platinum-iridium, the carefully guarded lump weighs exactly one kilogram. But more than just weighing one kilogram, it is the kilogram from which all other official kilograms are weighed.

International prototype kilogram with protective double glass bell

Known as the International Prototype Kilogram, or colloquially as Le Grand K, the weight was created in 1889 and has been carefully replicated to offer nations around the world a standardised kilogram. But over time Le Grand K and its clones have slightly deteriorated through wear and tear, despite extremely careful use. In an age of micro and nanotechnology, bits of metal aren’t quite accurate enough to dictate global weighs and so as of May this year it will no longer be the global measurement for a kilogram. An electromagnet is part of its replacement.

An electromagnet is effectively a magnet that is ‘turned on’ by running an electric current through it. Cutting the current turns it off, while increasing or decreasing the strength of the current increases and decreases the power of the magnet.

It can be used to measure a kilogram very precisely thanks to something called a Kibble Balance, which is essentially a set of scales. However, instead of using weights it uses an electromagnet to pull down one side. Because the electric current flowing through the electromagnet can be increased, decreased and measured very, very accurately, it means scientists can define any weight – in this case a kilogram – by the amount of electrical current needed to balance the scale.

This radical overhaul of how weights are defined means scientists won’t have to fly off to Paris every time they need precise kilograms. Beyond just replacing worn-out weights, however, it highlights the versatility and potential of electromagnets, from their use in electricity generation to creating hard drives and powering speakers.

The simple way to make a magnet

Magnets and electricity might at first not seem closely connected. One powers your fridge, the other attaches holiday souvenirs to it. The former certainly feels more useful. However, the relationship between magnetic and electric fields is as close as two sides of the same coin. They are both aspects of the same force: electromagnetism.

Electromagnetism is very complicated and there’re still aspects of it that are unknown today. It was thinking about electromagnetism that led Einstein to come up with his theory of special relativity. However, actually creating an electromagnet is relatively straightforward.

All matter is made up of atoms. Every neutral atom’s core is made up of static neutrons and protons, with electrons spinning around them. These electrons have a charge and a mass, giving the electrons a tiny magnetic field. In most matter all atoms are aligned in random ways and effectively all cancel each other out to render the matter non-magnetic. But if the atoms and their electrons can all be aligned in the same direction then the object becomes magnetic.

A magnet can stick to an object like a paperclip because its permanent magnetic field realigns the atoms in the paperclip to make it temporarily magnetic too – allowing the magnetic forces to line up and the materials to attract. However, once the paper clip is taken away from the magnet its atoms fall out of sync and point in random directions, cancelling out each other’s magnetic fields once again.

Whether a material can become magnetic or not relies on a similar principal as to whether it can conduct electricity. Materials like wood and glass are poor conductors because their atoms have a strong hold over their electrons. By contrast, materials like metals have a loose hold on their electrons and so are good conductors and easily magnetised. Nickle, cobalt and iron are described as ferromagnetic, because their atoms can stay in sync making them a permanent magnet. But when magnets really become useful is when electricity gets involved.

Putting magnets to work

Running an electric current through a material with a weak hold on its electrons causes them to align, creating an electromagnetic field. Because of the relationships between electric and magnetic fields, the strength of the electromagnet can also be altered by increasing or decreasing the current, while switching the flow of the current will flip its north and south poles.

Having this much control over a magnetic field makes it very useful in everyday life, including how we generate electricity.

Find out how we rewind a generator core in a clean room at the heart of Drax Power Station

Inside each of the six generator cores at Drax Power Station, is a 120-tonne rotor. When a voltage is applied, this piece of equipment becomes a massive electromagnet. When steam powers the turbines to rotate it at 3,000 rpm the rotor’s very powerful magnetic field knocks electrons in the copper bars of the surrounding stator out of place, sending them zooming through the metal, in turn generating an electrical current that is sent out to the grid. The 660 megawatts (MW) of active power Drax’s Unit 1 can export into the national transmission system is enough to power 1.3 million homes for an hour.

Beyond just producing electricity, however, electromagnets are also used to make it useful to everyday life.  Almost anything electric that depends on moving parts, from pumping loud speakers to circuit breakers to the motors of electric cars, depend on electromagnets. As more decarbonisation efforts lead to greater electrification of areas like transport, electromagnets will remain vital to daily life into the future.

How to get more EVs on the roads

25 January 2019

Electrification

From school runs to goods deliveries, getting from A to B is crucial to life in modern Britain. However, a progress report by the Committee on Climate Change (CCC) found that in 2017 transport was the largest greenhouse gas (GHG)-emitting sector in the UK, accounting for 28% of total emissions. Within domestic transport, cars, vans and HGVs are the three most significant sources of emissions, accounting for 87% of the sector’s emissions.

A zero carbon future relies on a major shift away from petrol and diesel engines to electric transport. A recent report, Energy Revolution: A Global Outlook, by academics from Imperial College London and E4tech, commissioned by Drax, examines the decarbonisation efforts of 25 major countries. The report found the UK ranked sixth in sales of new electric vehicles (EVs) in the 12 months to September 2018 and seventh for the number of charging points available.

The government’s Road to Zero strategy outlines the country’s target for as many as 70% of new car sales to be ultra-low emission by 2030, alongside up to 40% of new vans. It has, however, been criticised by the Committee on Climate Change as not being ambitious enough. A committee of MPs has suggested 2032 becomes the official target date for banning new petrol and diesel cars, rather than 2040 called for in the strategy.

Even as the range of EVs on the market grows, getting more low-emission vehicles on roads will require incentives and infrastructure improvements. Here’s how some of the countries leading the shift to electrified transport are driving adoption.

Expanding charging infrastructure

One of major barriers to EV adoption is a lack of public charging facilitates, coupled with reliability issues across a network that includes both old hardware and a plethora of apps and different connections. No one wants to set off on a long journey unsure of whether they’ll be able to find a recharging point before their battery goes flat.

According to the Energy Revolution report, there is one charger for every 5,000 people in the UK, compared to one for every 500 people in Norway, the leading country for charging points. The Scandinavian country’s government has invested heavily in its policy of placing two fast charging stations for every 50 km of main road, covering 100% of the cost of installation.

Government support has also been crucial in second and third ranked countries, The Netherlands and Sweden, respectively. The Dutch Living Lab Smart Charging is a collaboration between government and private organisations to use wind and solar to change vehicles. While Sweden has combined its ‘Klimatklivet’ investment scheme for both public and private charge points, with experiments, such as charging roads.

China, where half of the world’s 300,000 charge points are located, has issued a directive calling for the construction of 4.8 million electric charging points around the country by 2020. It’s also assisting private investments to make charging stations more financially viable.

The UK’s Road to Zero Strategy is to expand charging infrastructure through a £400 million joint investment fund with private investors.

Drax’s Energising Britain report found the UK is on track to meet its 2030 target of 28,000 installed chargers ahead of time. However, deployment still clusters around London, the South East and Scotland.

More direct government incentives or policies may be needed to balance this disparity and in the UK, the Scottish Government is leading the pack with a 2032 ban on new petrol and diesel cars plus a range of initiatives including public charging networks and the Switched on Towns and City Fund.

Charging points are necessary for electrified roads. However, it’s a chicken-and-egg situation –more chargers don’t mean more EVs. Getting more EVs on roads also requires financial incentive.

Money makes the wheels go around  

Putting infrastructure in place is one thing, but the reality is EVs are expensive, especially new ones and cold hard cash is an important driver of adoption.

Financial incentives have been a part of Norway’s policies since the 1980s, with the country’s high fuel prices, compared to the US for example, further helping to make EVs attractive. Current benefits for EV owners include: no import or purchase taxes, no VAT, no road tax, no road tolls, half price on ferries and free municipal parking. There are also non-financial incentives such as bus-lane usage.

Sweden, the second ranked country for new EV sales in 2018, is a similar case where high fuel prices are combined with a carrot-and-stick approach of subsidies for EVs and rising road taxes for fossil fuel-powered vehicles, including hybrids.

The UK has had a grant scheme in place since 2011, but last year removed hybrid vehicles from eligibility and dropped the maximum grant for new EV buyers from £4,500 to £3,500. EVs are also exempt from road taxes. In April 2019, Transport for London is implementing a Low Emissions Zone (ULEZ) which exempts EVs from a daily charge.

Subsidies for both buyers and vehicle manufacturers have been a cornerstone of China’s policies, with support coming up to around $15,000 per vehicle. Chinese EV buyers can also skip the lottery system for new license plates the country has in place to reduce congestion.

Heavy subsidies have allowed the country to claim as much as 50% of the entire EV passenger market, however, it makes change expensive and the government is now preparing to find a more sustainable way of driving adoption.

Preparing for transport beyond subsidies

China isn’t afraid to strong-arm manufacturers into building more EVs. Companies with annual sales of more than 30,000 vehicles are required to meet a quota of at least 10% EVs or hybrids. However, the government has begun to scale back subsidies in the hope it will drive innovation in areas such as batteries, robotics and automation, which will in turn reduce the price for end consumers.

Norway, which owes so much of its decarbonisation leadership in low-carbon transport to subsidies, is also grappling with how to move away from this model. As EVs creep increasingly towards the norm, the taxes lost through EV’s exclusions become more economically noticeable. While the government says the subsidies will remain in place until at least 2020, different political parties are calling to make the market commercially viable.

There is also concern the schemes only pass on savings to those who can afford new EV models, rather than the wider population, who face higher taxes for being unable to upgrade.

It’s not just governments’ responsibility to make new markets for EVs sustainable, but for business to innovate within the area too. Drax Group CEO Will Gardiner recently said his company must help to “ensure no-one is left behind through the energy revolution”.

That’s a view welcomed by politicians from all sides of the political spectrum concerned not just about mitigating man-made climate change but also to ensure a ‘just transition’ during the economy’s decarbonisation.

Energy and Clean Growth Minister Claire Perry spoke at an Aldersgate Group event in London in January:

“It’s been very easy, in the past, for concerns about the climate to be dismissed as the worries of the few, not the many. Luckily, we’ve been able to strip out a lot of the myths surrounding decarbonisation and costs –but we have to be mindful that this is a problem which will have to be solved by the many, not just the middle class.”

Many countries have set ambitious targets for when the ban of new petrol and diesel vehicles will come into effect. Government involvement and subsidies will be crucial but may prove economically challenging in the longer term.

Explore the full reports:

Energy Revolution: A Global Outlook

I. Staffell, M. Jansen, A. Chase, E. Cotton and C. Lewis (2018). Energy Revolution: Global Outlook. Drax: Selby.

Energising Britain: Progress, impacts and outlook for transforming Britain’s energy system

I. Staffell, M. Jansen, A. Chase, C. Lewis and E. Cotton, (2018). Energising Britain: Progress, impacts and outlook for transforming Britain’s energy system. Drax Group: Selby.

 

Where does global electricity go next?

12 December 2018

Power generation

Since the Paris Agreement came into effect in November 2016, it’s fair to say many countries have taken up the vital challenge of decarbonisation in earnest.

However, not all are making progress at the same rate. Many are not implementing the agreement at the pace needed to mitigate climate change, and keep the average global temperature increase well below 2oC of pre-industrial levels. Certainly not enough to limit the increase to 1.5oC by 2050, which the majority of climate scientists believe is necessary for the planet is to avoid dire consequences.

Last year even saw renewable energy investment fall 7%, while the money going into fossil fuels grew for the first time since 2014. And data released by the International Energy Agency (IEA) at the beginning of this month’s UN Climate Change Conference (COP24) in Katowice, Poland, found that 2017 was also the first for five years seeing an increase in advanced economies’ carbon emissions.

Despite this, there is much positive work towards decarbonisation.

A new report, Energy Revolution: A Global Outlook, by academics from Imperial College London and E4tech, commissioned by Drax, looks into the core areas and activities required to decarbonise the global energy system – and which countries are performing them to good effect. In doing this, the report also looks at how the UK stands in comparison and what steps countries need to take to truly decarbonise.

Here are the key indicators of decarbonisation and how countries around the world are performing towards them.

Dam in Hardangervidda, Norway

Clean power

At the forefront of reducing emissions and curbing climate change is the need to decarbonise electricity generation and move towards renewable sources.

Last year the global average carbon intensity was 440 grams of carbon dioxide (CO2) per kilowatt-hour (g/kWh). Out of the 25 major countries the report tracks, 16 came in below average, with seven of these falling under the long-term 50 g/kWh goal.

Leading the rankings are Norway, France and New Zealand, which have a near-zero carbon intensity for electricity generation, thanks to extensive hydro and nuclear power capacity.

At the other end of the table, China, India, Poland and South Africa remain wedded to coal, producing up to twice the global average CO2 for electricity generation. This comes despite China having installed two and a half times more renewables than any other country – it now boasts 600 gigawatts (GW) of renewable capacity.

Per person, Germany is leading the renewablesdrive with almost 1 kW of wind and solar capacity installed per person over the last decade. Despite this, as much as 40% of its electricity still comes from coal.

Part of the challenge in moving away from coal to renewables is economic, as many countries continue to subsidise their coal industries to keep electricity affordable. Phasing out these subsidies is therefore key to switching to a low-carbon generation system. Doing this works, as demonstrated by the example of Denmark, which cut its fossil fuel subsidies by 90% over the past decade, in turn successfully cutting its coal generation by 25%.

The UK’s carbon pricing strategy, which adds £16 per tonne of CO2emitted on top of the price set by the European emissions trading system (EU ETS), has led the carbon intensity of Great Britain’s electricity to more than halve in a decade. It highlights how quickly and effectively these kinds of fees can make fossil fuels uneconomical. Since 2008 the UK has removed more than 250 g/kWh from its electricity production.

Carbon capture and storage

In many future looking climate scenarios, keeping the earth’s temperature below a 2oC increase depends on extensive deployment of carbon capture technology – capturing as much as 100 billion tonnes of CO2 per year. Storing and using carbon is clearly forecast to be a major part of any attempt to meet the Paris Agreement, but at present there are few facilities carrying it out at scale.

Around the world today there are 18 large-scale carbon capture and storage (CCS) units running across six countries with a total capacity to capture 32 million tonnes of CO2 per year (MtCO2p.a). Another five facilities are under construction in three countries to add another 7 MtCO2p.a of global capacity. In the UK, Drax Power Station is piloting a bioenergy carbon capture and storage programme that could make it the world’s first negative emissions power station.

The USA has the greatest total installed capacity at 20 MtCO2p.a., but per person it ranks behind Norway, Canada and Australia. Their smaller populations give them more than 200 kg of carbon capture capacity per person per year.

Oil platform off the coast of Australia

These figures are well below the 100 billion tonnes the IEA estimates need to be stored by 2060 to prevent temperatures reaching 2oC more. However, considering the US alone has a potential storage capacity of more than 10 trillion tonnes of CO2, the potential of storage is not expected to be a problem.

Using depleted oil or natural gas fields as storage for captured carbon is being explored in a number of regions, with the US establishing several projects with more than 1 million tonnes in capacity. In 2019, Australia will open the world’s largest CO2store with the capacity to capture between 3.4 million and 4 million tonnes a year from Chevron’s Gorgon gas facility.

Considering the storage capacity available globally, it’s a matter of deploying the necessary technology for CCS to have a significant impact on emissions and global warming. The UK is perhaps a typical example of where CCS is at present with estimated storage capacity of 70 billion tonnes, as much as half of the entire EU combined. By repurposing North Sea oil and gas fields in partnership with Norway, the UK could pool its carbon storage capacity.

Electrification

Electricity generation is one of the main targets for emissions reductions globally. As a result of the progress that’s been made in this field, many future-looking scenarios highlight the important of electrification in other sectors, such as transport, in turn making them less carbon intensive.

Transport is leading the charge globally – there are now 10 different countries where one of every 50 new vehicles sold is electric. In Norway, this ratio is almost one in two, thanks in part to generous tax exemptions as well as non-financial incentives like access to bus lanes and half-price ferries.

Perhaps surprisingly, China is the world’s largest electric vehicle (EV) market. It may still use significant amounts of coal, but its commitment to reducing urban air pollution has seen it push EVs heavily, and it now accounts for 50% of the global battery EV market on its own.

Chinese electric car charging stations

Of course, adoption of EVs requires the supporting infrastructure to be truly successful. In conjunction with its high sales, Norway leads the way in charging points per capita, with one for every 500 people. This compares to one charger for every 5,000 people in the UK and one for every 10,000 people in China.

Electrification also affects the energy intensity of country’s transport systems and while it may be the largest EV market, China’s rise in private vehicles has been largely driven by petrol and diesel models. The result is the largest increases in transport energy intensity and emissions has taken place in China, Indonesia and India, respectively.

Domestic energy intensity is also rising in China, Indonesia and South Africa, as greater numbers of people gain access to appliances and home comforts. Conversely in Europe, Portugal, Germany and the Netherlands have all seen their domestic energy intensity drop in the last decade. However, this may be the lingering effect of the 2008 recession rather than long-term efficiency improvements.

The efficiency of industrial processes is also an important barometer in decarbonisation. Activities like mining and manufacturing require heavy-duty diesel-powered machinery and often coal-powered generators, especially in BRIC nations. The exception is China, where plans to get the 1,000 most energy-intensive companies to reduce their energy consumption per unit of GDP produced by 20% over the last five years, has proved fruitful.

Norway’s heavily-electrified industries, however, are still energy intensive and its level of carbon intensity is vulnerable to fluctuations in power generation prices.

Electrification and reduced emissions require government policies to put in motion behavioural changes that can lead to lasting decarbonisation. “Robust carbon pricing is one of the most effective tools to enabling a zero carbon, lower cost energy future,” Drax Group CEO Will Gardiner commented recently.

Welcoming a November report by the Energy Transitions Commission, Gardiner said:

“The cost of inaction far outweighs the cost of doing something now.”

Explore the full report: Energy Revolution: A Global Outlook.

I. Staffell, M. Jansen, A. Chase, E. Cotton and C. Lewis (2018). Energy Revolution: Global Outlook. Drax: Selby.

Drax commissioned independent researchers from Imperial College London and E4tech to write Energy Revolution: A Global Outlook, which looks into the core areas and activities required to achieve decarbonisation – and which countries are performing them to good effect. In doing this it also looks at how the UK stands in comparison and what steps countries need to take to truly decarbonise.

Energy Revolution: A Global Outlook

5 December 2018

Carbon capture

Read the full report [PDF]

The global energy revolution

As a contribution to COP24, this report informs the debate on decarbonising the global energy system, evaluating how rapidly nations are transforming their energy systems, and what lessons can be learned from the leading countries across five energy sectors.

It was commissioned by power utility Drax Group, and delivered independently by researchers from Imperial College London and E4tech.

Clean power

  • Several countries have lowered the carbon content of their electricity by 100 g/kWh over the last decade. The UK is alone in achieving more than
    double this pace, prompted by strong carbon pricing.
  • China is cleaning up its power sector faster than most of Europe, however several Asian countries are moving towards higher-carbon electricity.
  • Germany has added nearly 1 kW of renewable capacity per person over the last decade. Northern Europe leads the way, followed by Japan, the US and China. In absolute terms, China has 2.5 times more renewable capacity than the US.

Fossil fuels

  • Two-fifths of the world’s electricity comes from coal. The share of coal generation is a key driver for the best and worst performing countries in clean power.
  • Coal’s share of electricity generation has fallen by one-fifth in the US and one-sixth in China over the last decade. Denmark and the UK are leading the way. Some major Asian nations are back-sliding.
  • Many European citizens pay out $100 per person per year in fossil fuel subsidies, substantially more than in the US or China. These subsidies are growing in more countries than they are falling.

Electric vehicles

  • In ten countries, more than 1 in 50 new vehicles sold are now electric. China is pushing ahead with nearly 1 in 25 new vehicles being electric and Norway is in a league of its own with 1 in 2 new vehicles now electric, thanks to strong subsidies and wealthy consumers.
  • There are now over 4.5 million electric vehicles worldwide. Two thirds of these are battery electric, one third are plug-in hybrids. China and the US together have two-thirds of the world’s electric vehicles and half of the 300,000 charging points.

Carbon capture and storage

  • Sufficient storage capacity has been identified for global CCS roll-out to meet climate targets, but large-scale CO2 capture only exists in 6 countries.
  • Worldwide, 5 kg of CO2 can be captured per person per year. The planned pipeline of CCS facilities will double this, but much greater scale-up is needed as this represents only one-thousandth of the global average person’s carbon footprint of 5 tonnes per year.

Efficiency

  • Global progress on energy intensity is mixed, as some countries improve efficiency, while others increase consumption as their population become wealthier.
  • Residential and transport changes over the last decade are mostly linked to the global recession and technological improvements, rather than behavioural shift.
  • BRICS countries consume the most energy per $ of output from industry. This is linked to the composition of their industry sectors (i.e. greater manufacturing and mining activity compared to construction and agriculture).

continued … [View PDF]

I. Staffell, M. Jansen, A. Chase, E. Cotton and C. Lewis (2018). Energy Revolution: A Global Outlook. Drax: Selby.

View press release:

UK among world leaders in global energy revolution

Negative emissions techniques and technologies you need to know about

28 November 2018

Carbon capture

Cutting carbon emissions is the headline environmental policy for the 195 countries signed up to the Paris Climate Agreement – and so it should be. Decarbonisation is crucial to keeping global warming below 2oC and avoiding or at least mitigating potentially dire consequences for our planet, its people and biodiversity.

However, centuries of pumping out carbon dioxide (CO2) from factories, vehicles and power plants means it’s not enough just to reduce output. Countries must also work on CO2 removal (CDR) from the atmosphere. Implemented at scale, what’s also known as Greenhouse Gas Removal (GGR) could mean a country or facility removing more CO2 than it emits – effectively giving it negative emissions.

Achieving this is not only advantageous to combating climate change, it’s essential. A new report from the Intergovernmental Panel on Climate Change (IPCC) explores 116 scenarios in which global warming is kept to 1.5 oC of pre-industrial levels (more ambitious than the Paris Agreements 2oC). Of these scenarios, 101 use negative emissions technologies (NETs) at a scale of between 100 to 1,000 gigatonnes* over the 21st century.

Given the scale of the ambition, the task of capturing enough carbon to be truly negative will need to rely on many sources. Here are some of the techniques, technologies, and innovations aiming to push the world towards negative emissions.

  1. Forests

Weyerhaeuser Nursery, Camden, Alabama

CDR doesn’t have to utilise complex tech and chemistry. The planet’s natural carbon cycle already removes and stores huge amounts of carbon from the atmosphere – primarily through trees. The world’s forests have absorbed as much as 30% of annual global human-generated CO2 emissions over the last few decades.

Regenerating depleted forests (reforestation), planting new forests (afforestation), and protecting and helping existing forests thrive through active management can all contribute to offsetting emissions.

The IPCC report estimates that reforestations and afforestation could potentially capture 0.5 and 3.6 billion tonnes of CO2 a year at a cost of USD$5 to $50 (£3.90 to £39) per metric tonne.

There are potential drawbacks of extensive afforestation. It could compete with food crops, as well as reducing the reflection of heat and light back into space that arid lands currently offer to prevent global warming.

  1. Bioenergy with carbon capture and storage

Europe’s first BECCS pilot project at Drax Power Station

Biomass on its own is an important fuel source in lowering emissions from industries such as power generation. On one hand, it’s created by organic material, which during its lifetime absorbs carbon from the atmosphere (often enough to offset emissions from transportation and combustion). On another, it creates a sustainable market for forestry products, encouraging landowners to responsibly manage forests, which in turn can lead to growing forests and increased CO2 absorption.

But when combined with carbon capture and storage (CCS or CCUS) technology it becomes a negative carbon emissions process, known as BECCS. Drax is partnering with carbon capture company C-Capture in a £400,000 pilot to develop CCS technology, which will remove a tonne of carbon from its operations a day. Combined with the carbon removed by the forests supplying the biomass, it could turn Drax into the world’s first negative emissions power station.

Beyond just storing the captured carbon underground, however, it can be used to create a range of products, locking in and making use of the carbon for much longer.

The IPCC report estimates between 0.5 and 5 billion metric tonnes of carbon could be captured globally this way at a cost of $100 to $200 (£80-160) per metric tonne.


  1. Increased ‘blue carbon’

Mangrove roots

It’s not only forests of fast-growing pines or eucalyptus that remove CO2 from the atmosphere. In fact, coastal vegetation such as mangroves, salt marshes and sea grasses suck in and store carbon in soil at a greater rate than plants on land. The carbon stored in these waterside ecosystems is known as ‘blue carbon’.

Human encroachment and development on coastlines has depleted these environments. However, efforts are underway to regenerate and expand these hyper-absorbent ecosystems –turning them into carbon sinks that can remove more emissions from the atmosphere than conventional forests. Apple is currently throwing its financial weight behind a mangrove expansion project in Colombia to try and offset its global operations.

  1. Boosting ocean plants’ productivity

Beyond costal mangroves, the ocean is full of plants that use CO2 to photosynthesise – in fact, the oceans are thought to be one of the world’s largest carbon sinks. But there are some people who think we could enhance marine plants’ absorption abilities.

Eelgrass Bed

One such approach involves injecting iron nutrients into the ocean to prompt a bloom in microscopic plants called phytoplankton, which float in the upper part of the ocean absorbing the CO2 absorbed from the atmosphere. When the plants eventually die they then sink trapping the absorbed carbon on the seabed.

An additional positive effect would be an increase in dimethyl sulphide, which marine plants emit. This could alter the reflectivity of clouds that absorb water from the ocean and further act to cool the earth.

  1. Enhanced rock weathering

Plants absorbing CO2 through photosynthesis is the most-commonly known part of the carbon cycle, however, rocks also absorb CO2 as they weather and erode.

The CO2 usually reaches the rock in the form of rain, which absorbs CO2 from the atmosphere as it falls. It then reacts with the rocks, very slowly breaking them down, and forming a bicarbonate that is eventually washed into the ocean, locking the carbon on the seabed.

The problem is it takes a long time. One idea that seeks to use this natural process more effectively is to speed it up by pulverising rocks and spreading the resulting powder over a larger area to absorb more CO2 from rain and air.

Natural rock weathering currently absorbs around 0.3% of global fossil fuel emissions annually, but the IPCC estimates at scale it could capture 2 and 4 billion metric tons at a cost of between $50 and $200 (£39-160) per metric ton. This approach also requires extensive land use and has not been trialled at scale.

  1. Sequestering carbon in soil

Soil is another major carbon sink. Plants and grasses that die and rot store carbon in the soil for long periods. However, modern farming techniques, such as intensive ploughing and fertilisation, causes carbon to be released and oxidised to form CO2.

Adjustments in farming methods could change this and, at scale, make agriculture carbon neutral. Straightforward techniques such as minimising soil disturbance, crop rotation and grassland regeneration could sequester as much as 5 billion tonnes of carbon into the soil annually, according to the IPCC, at potential zero cost.

A challenge to this method is that once soil is saturated it can’t hold any more carbon. That material would also be easily released if methods are not maintained in the future.

  1. Increasing soil carbon with biochar

A way to super-charge how much carbon soil can store is to add a substance called biochar to the earth. A type of charcoal made by burning biomass, such as wood or farm waste, in the absence of oxygen, biochar can increase the amount of carbon locked into the soil for hundreds or thousands of years. It also helps soil retain water, and reduce methane and nitrogen emissions.

Biochar has only been trialled at a small scale but the IPCC estimates that between 0.5 and 2 billion metric tonnes could be captured annually through this means. However, it predicts a cost of between $30 and $120 (£23-94) per metric tonne. Additionally, producing biochar at scale would require large amounts of biomass that must be sustainably sourced.

  1. Direct air capture

CO2 is in the air all around us and so removing it from the atmosphere can effectively take place anywhere. Direct air capture (DAC or DACCS) proposes that the carbon capture and storage technology many power stations are now trialling can be carried out almost anywhere.

Swiss start-up Climeworks is one company attempting to make DAC viable. Its technology works by passing air through a surface that reacts with CO2 to form a compound, but releases the remaining air. The newly formed compound is then heated so the reactive chemical agent can be separated and reused. The CO2 is then stored underground with gas and water where it reacts with basalt and turns to stone in less than two years.

The main challenge for this technique is the cost – between $200 and $600 (£156-468) per metric tonne – and that it requires large amounts of energy, creating further demand for electricity.

One hundred million tonnes

Wood pellet storage domes at Drax Power Station, Selby, North Yorkshire

The primary challenge for negative emission technology as a whole is that so few have actually been implemented at a global scale. However, trials are in motion around in the world, including at Drax, to remove emissions and help limit the effects of climate change.

Even if the UK decarbonises heavily across all sectors of the economy by 2050, there’s still projected to be 130 MtCO2 (million tonnes of carbon dioxide) net emissions. But a Royal Academy/Royal Society report released earlier this year was optimistic. It concluded that the country can become net zero and do its part in mitigating man made climate change – with BECCS identified as the negative emissions technology best suited to take the leading role and at least cost.

Learn more about carbon capture, usage and storage in our series: