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Joined at the volts: what role will interconnectors play in Great Britain’s electricity future?

For more than 50 years Great Britain has been electrically connected to Europe. The first under-sea interconnector between British shores and the continent was installed in 1961 and could transmit 160 megawatts (MW) of power. Today there is 4 gigawatts (GW) in interconnector capacity between Great Britain, France, Ireland and the Netherlands – and there’s more on the way.

By the mid-2020s some estimates suggest interconnector capacity will reach 18 GW thanks to new connections with Germany, Denmark and Norway. The government expects imports to account for 22% of electricity supply by 2025, up from 6% in 2017.

This increased connectivity is often held up as a means of securing electricity supply and while this is largely true, it doesn’t tell the full story.

In fact, this plan could risk creating a dependency on imported electricity at a time when flexibility and diversity of power sources are key to meeting demand in an increasingly decentralised, decarbonising system.

Great Britain needs to be connected and have a close relationship with its European neighbours, but this should not come at the expense of its power supply, power price or ongoing decarbonisation efforts. Yet these are all at risk with too great a reliance on interconnection.

To secure a long term, stable power system tomorrow, these issues need to be addressed today.

Unfair advantage

At their simplest, interconnectors are good for the power system. They connect the relatively small British Isles to a significant network of electricity generators and consumers. This is good for both helping secure supply and for broadening the market for domestic power, but the system in which interconnectors operate isn’t working.

Since 2015 interconnectors have had the right to bid against domestic generators in the government’s capacity market auctions.

The government uses these auctions to award contracts to generators that can provide electricity to the grid through existing or proposed facilities. The original intention was also to allow foreign generators to participate. As an interim step, the transmission equipment used to supply foreign generators’ power into the GB market – interconnectors – have been allowed to take part. In practice, interconnectors end up with an economic advantage over other electricity producers.

Firstly, interconnectors are not required to pay to use the national transmission system like domestic generators are. This charge is paid to National Grid to cover the cost of installation and maintenance of the substations, pylons, poles and cables that make up the transmission network. Plus the cost of system support services keeping the grid stable. Interconnectors are exempt from paying these despite the fact imported electricity must be transported and balanced within England, Scotland and Wales in the same way as domestic electricity.

Secondly, interconnectors don’t pay carbon tax in the GB energy market. The Carbon Price Floor is one of the cornerstones of Great Britain’s decarbonisation efforts and has enabled the country’s electricity system to become the seventh least carbon-intense of the world’s most power intensive systems in 2016, up from 20th in 2012.

Interconnectors themselves do not emit carbon dioxide (CO2) in Great Britain, but this does not mean they are emission-free. France’s baseload electricity comes largely from its low-carbon nuclear fleet, but the Netherlands and Ireland are still largely dependent on fossil fuels for power. Because the European grid is so interconnected even countries which don’t yet have a direct link to Great Britain, such as Germany with its high carbon lignite power stations, also contribute to the European grid’s supply. The Neuconnect link is planned to connect Germany and GB in the late 2020s.

Not being subject to the UK’s carbon tax – only to the European Union’s Emissions Trading System (EU ETS) which puts a much lower price on CO2 – imported power can be offered cheaper than domestic, lower-carbon power. This not only puts Great Britain at risk of importing higher carbon electricity in some cases, but also exporting carbon emissions to our neighbours when their power price is higher to that in the GB market..

This prevents domestic generators from winning contracts to add capacity or develop new projects that would secure a longer-term, stable future for Great Britain. In fact, introducing more interconnectivity could in some cases end up leading to supply shortages, be they natural or market induced.

Under peak pressure

The contracts awarded to interconnectors in the capacity market auctions treat purchased electricity as guaranteed. But, any power station can break down – any intermittent renewable can stop generating at short notice. Supply from neighbouring countries is just the same.

Research by Aurora found that historically, interconnectors have often delivered less power than the system operator assumed they would and on occasion exported power at times of peak demand. This happened recently during the Beast of the East, when low temperatures across the continent drove electricity demand soaring.

This European-wide cold spell meant Ireland and France (which has a largely electrified heating system) experienced huge electricity demand spikes, driving power prices up.

As a result, for much of the time between 27 and 28 February Great Britain exported electricity to France to capitalise on its high prices. This not only led to more fossil fuels being burned domestically, but it meant less power was available domestically at a time when our own demand was exceptionally high. Even when the interconnectors do flow in our direction they cannot provide crucial grid services like inertia so our large thermal power stations are often still needed.

It is difficult to say for certain how interconnectors will function during times of high demand in the future due to a lack of long-term data, but that which we do know and have seen suggests they don’t always play to the country’s best interests.

There is still an important role for interconnectors on the Great Britain grid, but to deliver genuine value the system needs to be fairer so they don’t skew the market.

Where interconnectors fit into the future

Interconnectors bring multiple benefits to our power system. They can help with security of supply by bringing in more power at times of systems stress, with the right system in place they can help reduce the need to rely on domestic fossil fuels and enable more renewable installation, and if electricity is being generated cheaper abroad, they can also create opportunities to reduce costs for consumers.

However, the correct framework must be put in place for interconnectors to bring such benefits while allowing for domestic projects that can help secure the country’s electricity supply.

As a start, interconnectors should be reclassified – known as de-rating – to compete with technologies on an equal footing.

Drax’s proposed OCGT plants, which can very quickly start up and provide the grid with the power and balancing services it needs, before switching off again, could offer a more reliable route to grid stability than such overwhelming dependence on interconnectors will. In addition, the coal-to-gas and battery plans at Drax Power Station, would prove to be a highly flexible national asset.

New gas and interconnectors should be able to compete fairly with one another. Policymakers should facilitate a system that allows competing technologies to exist in a cost beneficial way. Both interconnectors and domestic thermal power generators can play their part in creating stability, transitioning towards a decarbonised economy and fitting within the UK’s industrial strategy.

In 1961, when the first interconnector was switched on it marked a new age of continental co-operation. Five decades on we should not forget this goal. In an ever more complex grid, what we need is different technologies, systems and countries working together to achieve a flexible, stable and cleaner power system for everyone.

Better forest management 

One of the most interesting outcomes of the recent analysis from the UK’s Forest Research (FR) agency on the Carbon Impact of Biomass (CIB) is the call for regulation to ensure better forest management and appropriate utilisation of materials.

The research was commissioned by the European Climate Foundation (ECF) to follow up FR’s mighty tome from 2015 of the same name.

This new piece of work essentially aims to clarify the findings of the initial research with supplementary analysis to address 3 key areas:

  1. A comparison of scenarios that may give relatively higher or lower GHG reductions — in simple terms, providing examples of both good and bad biomass.
  2. Based on the above, the report “provides a statement of the risks associated with EU bioenergy policy, both with and without specific measures to ensure sustainable supply.”
  3. It then goes on to “provide a practical set of sustainability criteria to ensure that those bio feedstocks used to meet EU bioenergy goals deliver GHG reductions”.

Not surprisingly, the report finds that unconstrained and unregulated use of biomass could lead to poor GHG emission results, even net emissions rather than removals. This, again, is a no-brainer. No reasonably minded person, even the most ardent bio-energy advocate, would suggest that biomass use should be unconstrained and unregulated.

There are plenty of obvious scenarios where biomass use would be bad, but that doesn’t mean that ANY use of biomass is bad. Thankfully this analysis takes a balanced view and identifies a number of scenarios where the use of biomass delivers substantial GHG emission reductions.

The report identifies the use of forest and industrial residues and small/early thinnings as delivering a significant decrease in GHG emissions, this is characterised as “good biomass” — around 75% of Drax’s 2017 feedstock falls into these feedstock categories (including some waste materials).

The remainder of Drax’s 2017 feedstock was made up of low grade roundwood produced as a bi-product of harvesting for saw-timber production. This feedstock was not specifically modelled in the analysis, but the report concludes that biomass users should: Strongly favour the supply of forest bioenergy as a by-product of wood harvesting for the supply of long-lived material wood products. The low grade roundwood used by Drax falls into this category.

Among the more obvious suggested requirements are that biomass should not cause deforestation and that biomass associated with ‘appropriate’ afforestation should be favoured. Agreed.

Another interesting recommendation is that biomass should be associated with supply regions where the forest growing stock is being preserved or increased, improving growth rates and productivity. Drax absolutely supports this view and we have talked for some time about the importance of healthy market demand to generate investment in forest management, encourage thinning and tree improvement.

Timber markets in the US South have lead to a doubling of the forest inventory over the last 70 years. These markets also provide jobs and help communities and ensure that forests stay as forest rather than being converted to other land uses.

The importance of thinning, as a silvicultural tool to improve the quality of the final crop and increase saw-timber production, is recognised by Forest Research. This is an import step in accepting that some biomass in the form of small whole trees can be very beneficial for the forest and carbon stock but also in displacing fossil fuel emissions.

The forest resource of the US South is massive, it stretches for more than a thousand miles from the coast of the Carolinas to the edge of West Texas, a forest area of 83 million ha (that’s more than 3 times the size of the UK). Given that a wood processing mill typically has a catchment area of around a 40–50-mile radius, imagine the number of markets required for low grade material to service that entire forest resource!

So, what happens when there isn’t a market near your forest, or the markets close? Over the last 20 years more than 30 million tonnes of annual demand for low grade timber — thinnings and pulpwood — has been lost from the market in the US South as the paper and board mills struggled after the recession. What happens to the forest owner? They stop harvesting, stop thinning, stop managing their forest. And that reduces the rate of growth, reduces carbon sequestration and reduces the quantity of saw-timber that can be produced in the future. Recognising that biomass has provided essential markets for forest owners of the US South, and directly contributed to better forest management is a really important step.

The CIB report talks about different types of biomass feedstock like stumps, which Drax does not use. Conversely the report also identifies good sources of biomass which should be used such as post-consumer waste, which Drax agrees would be better utilised for energy where possible, rather than land fill. It also shows that industrial processing residues that would otherwise be wasted and forest residues that would be burnt on site or left to rot would deliver carbon savings when used by facilities like Drax.

All of these criteria are similar to those outlined in the 7 principles of sustainable biomass that Drax has suggested should be followed.

Among the other recommendations which echo Drax’s thinking are that biomass should not use saw-timber or displace material wood markets, the scale should be appropriate to the long term sustainable yield potential of the forest — it should be noted that harvesting levels in the US South are currently only at around 57% of the total annual growth.

Counterfactual modelling, like that used in this report, cannot take account of all real-world variables and must be based on generic assumptions so should not be used in isolation, but this report makes a very useful contribution to a complex debate.

It is possible to broadly define good and bad biomass and to look at fibre baskets like the US south and see a substantial surplus of sustainable wood fibre being harvested a rate far below the sustainable yield potential.

Drax is currently working with the authors of this report, and others in the academic world, to develop the thinking on forest carbon issues and to ensure that all biomass use is sustainable and achieves genuine GHG emission reductions.

Discover the steps we take to ensure our wood pellet supply chain is better for our forests, our planet and our future — visit ForestScope

6 start-ups, ideas and power plants shaping biomass

Humans have used wood as a source of fuel for over a million years. Modern biomass power, however, is a far cry from human’s early taming of fire and this is down to constant research and innovation. In fact, today it’s one of the most extensively researched areas in energy and environmental studies.

With biomass accounting for 64% of total renewable energy production in the EU in 2015, the development isn’t likely to stop. Ongoing advancements in the field are helping the technology become more sustainable and efficient in reducing emissions.

Here are seven of the projects, businesses, ideas and technologies pushing biomass further into the future:

Torrefaction – supercharging biomass pellets

When it comes to making biomass as efficient as possible it’s all down to each individual pellet. Improving what’s known as the ‘calorific value’ of each pellet increases the overall amount of energy released when they are used in a power station.

One emerging process aiming to improve this is torrefaction, which involves heating biomass to between 250 and 300 degrees Celsius in a low-oxygen environment. This drives out moisture and volatiles from woody feedstocks, straw and other biomass sources before it is turned into a black ‘biocoal’ pellet which has a very high calorific value.

This year, Estonian company Baltania is constructing the first industrial-scale torrefaction plant in the country with the target output of 160,000 tonnes of biocoal pellets per year. If it’s successful, power stations worldwide may be able to get more power from each little pellet.

bio-bean – powered by caffeine

Biofuels don’t just come from forest residues. Every day more than two billion cups of coffee are consumed globally as people get themselves caffeinated for the day ahead. In London alone, this need for daily stimulation results in more than 200,000 tonnes of coffee waste produced every year. More often than not this ends up in landfills.

bio-bean aims to change this by collecting used coffee grounds from cafes, offices and factories and recycling them into biofuels and biochemicals. The company now recycles as much as 50,000 tonnes of coffee grounds annually while one of its products, B20 biodiesel, has been used to power London buses. bio-bean also produces briquettes and pellets, which, like woody biomass, can serve as an alternative to coal.

Biomass gasification – increasing the value of biomass waste

Biogas is often seen as a promising biofuel with fewer emissions than burning fossil fuels or biomass pellets. It’s an area undergoing significant research as it points to another means of creating higher-value products from biomass matter.

The Finnish town of Vaasa is home to the world’s largest gasification plant. The facility is part of a coal plant where co-firing biogas with coal has allowed it to reduce carbon dioxide (CO2) emissions by as much as 230,000 tonnes per year.

As well as reducing emissions, co-firing allows the power plant to use 25% to 40% less coal and when demand is low in the autumn and spring months, the plant runs entirely on biogas. More than that, the forestry residues which are used to produce the biogas are sourced locally from within 100 km of site.

(As part of our transition away from coal, co-firing biomass with that fossil fuel took place at Drax Power Station from 2003 until full unit conversions became a reality in 2013.)

Lynemouth Power Station – powering the move away from coal

After 44-years, the coal-fired Lynemouth Power Station in Northumberland is the latest UK power producer converting to biomass-fuel. Set for completion this year, the plant will supply 390 MW of low-carbon electricity to the National Grid, enough to power 700,000 homes.

Every new power station conversion poses different challenges as well as the opportunity to develop new solutions, but none are as crucial as the conversion of the materials handling equipment from coal to biomass pellets. While coal can sit in the rain for long periods of time and still be used, biomass must be kept dry with storage conditions constantly monitored and adjusted to prevent sudden combustion.

At Lynemouth the handling of 1.4 million tonnes of biomass annually has required the construction of three, 40-metre high concrete storage silos, as well as extensive conveyor systems to unload and transport biomass around the plant. 

BioTrans – two birds with one stone

Energy and food are both undergoing serious changes to make them more sustainable. Danish startup BioTrans is tackling both challenges by using one of the food industry’s key pain points – wastage – to create energy with its biogas systems.

The company installs systems that collect leftover food from restaurants and canteens and stores it in odour-proof tanks before collecting and turning it into biogas for heating and electricity production. More than just utilising this waste stream, the by-product of the gasification process can also be sold as a fertiliser.

Drax and C-Capture – cutting emissions from the source

Carbon capture, usage and storage (CCUS) is one of the most important fields in the energy sector today. The technology’s ability to capture CO2 from the electricity generation process and turn it into a revenue source before it can enter the atmosphere means it’s attracting significant investment and research.

Drax is partnering with C-Capture, a company spun out of the University of Leeds’ chemistry department, to trial a new form of CCUS. The pilot scheme will launch in November and aims to capture a tonne of CO2 per day from one of Drax’s biomass units.

C-Capture’s technology could make the process of capturing and storing CO2 less costly and energy intensive. It does this using a specially developed solvent capable of isolating CO2 before being recycled through the system and capturing more.

If the pilot proves successful, the technology could be implemented at an industrial scale, seeing up to 40% of the CO2 in the flue gases from Drax’s biomass units captured and stored. If the technology tested at Drax leads to the construction of a purpose-built carbon capture unit elsewhere, scientists and engineers at C-Capture believe the CO2 captured could exceed 90%.

Back in North Yorkshire, the eventual goal is negative carbon emissions from Drax Power Station – its biomass units already deliver carbon savings of more than 80% compared to when they used coal. And if a new revenue stream can be developed from the sale of the carbon captured then the power produced from biomass at the power station could become even more cost effective.

With thanks to Biomass UK and The European Biomass Association (AEBIOM).

The quarter when weather dictated Great Britain’s electricity

As summer arrives in Great Britain, bringing the hottest May Day Bank Holiday on record, it’s hard to believe March saw the coldest spring day since records began. But that’s exactly what happened during the six days the ‘Beast from the East’ hit Europe.

From 26 February to 3 March Great Britain’s weather sunk to a once-in-a-decade level of cold, dipping on 1 March when thermometers dropped to an average of -3.8 degrees Celsius across central England. These extreme conditions drove electricity demand up 10%, as darker days required extra lighting and more people plugged in energy-intensive electric heaters to keep warm.

After successive years of milder winters, January to March made for a period in which the weather played a pivotal role in dictating how the country’s electricity was generated, according to Electric Insights, a quarterly report commissioned by Drax and written by researchers from Imperial College London.

The report highlights how despite the storm disrupting power transmission in parts of the country, and sensationalist headlines suggesting lights could go out at any moment, the electricity system held up well in the adverse conditions.

The Beast from the East tests energy security

The sub-zero temperatures, brutal wind and Siberian-level snow blizzards that hit Great Britain for six days between February and March proved a real test for the electricity system. The evening of 1 March saw demand reach 53.3 GW – its highest peak in three years. This had a knock-on effect on the hour-ahead price of electricity, which was 50% higher during March than the same period in 2017.

The weather had a notable impact on the types of generation needed to power the county, with fossil fuels playing an important role at the expense of carbon emission levels. Over the six-day cold spell, fossil fuels averaged between 20-25 GW of electricity generation.

Coal accounted for almost 10% of the total electricity mix across the quarter, in part because of rising gas prices, which made it a more economical fuel. Gas, however, remained the biggest power source accounting for just shy of 40% of all electricity.

What is most significant about this Q1 2018 fossil fuel usage, is that even in such extreme weather, coal and gas generation was still 16% and 2% lower, respectively, than the same quarter in 2017.

This drop is the result of increased renewable capacity allowing wind generation to grow by almost 40% and make up just short of 20% of the electricity mix.

Read the full articles here: 

Rampant wind leads renewable generation

The conditions brought by the storm where particularly favourable to wind generation, which hit new peak-generation levels of 13 GW on 17 January and then 14 GW on 17 March. Over the full quarter wind power production reached 15,560 GWh, 30 GWh more than nuclear, the nearest low carbon source. This increase comes in part as a result of a 19% increase in installed capacity around the country since Q1 2017, but also thanks to the grid getting better at making use of it.

During the six sub-zero days of the quarter, wind contributed a minimum of 4.4 GW, crucial at a time when other power sources appeared vulnerable. For example, heavy snowfall blocked solar panels from the sun leaving it contributing just 2% of the electricity mix over the quarter.

Nuclear power fared better and made up just shy of 20% of generation, but was held back by two routine reactor maintenances while a third shut on the quarter’s coldest day due to seaweed clogging a plant’s cooling system. Biomass ran solidly throughout the cold spell, contributing 4% of the total electricity generation mix.

The opening of a new 2.2 GW cable connecting Scotland – where there is 7.7 GW of installed capacity – to North Wales saved National Grid some £9 million a month in constraint payments across the first quarter.

Read the full articles:

Did the country almost run out of gas?

One of the most headline-grabbing events from the cold spell was National Grid’s decision to issue a ‘Gas Deficit Warning’ on the morning of 1 March, suggesting supplies could run out before the end of the day.

With 83% of British households depending on gas for heating and gas turbines accounting for a significant portion of the country’s electricity generation, the announcement drew considerable press attention.

However, National Grid explained domestic gas users would unlikely be impacted and it would work with industrial partners to make more gas available to meet demand. This clearly had the desired effect, with as much as 19 GW of spare gas capacity ending up available that day. The warning was withdrawn the following morning and gas generation averaged 11 GW, more than any other source, between 26 February and 3 March.

Nevertheless, European-wide demand for gas sent prices soaring and making it more economical to burn coal, which generated roughly 10 GW a day on average over the six-day period of 26 February to 3 March.

Read the full article: Running low on gas

The extreme weather of Q1 2018 highlighted the stability of Great Britain’s overall power system. But even as the country continues to move towards greater renewable generation, fossil fuels continue to play an important part of electricity mix when demand peaks.

Explore the data in detail by visiting 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.

Keeping the electricity system’s voltage stable

Electricity high voltage sign

In day-to-day life, the electricity system normally plays a consistent, unfluctuating role, powering the same things, in the same way. However, behind the scenes electricity generation is a constant balancing act to keep the grid stable.

Power stations themselves are like living animals, in need of continuous adjustment. Transmission networks need continual maintenance and keeping the whole grid at a frequency of 50 Hz takes careful monitoring and fine-tuning.

One of the other constant challenges for Great Britain’s electricity system is keeping voltage under control.

Keeping the volts in check

Voltage is a way of expressing the potential difference in charge between two points in an electrical field. In more simplistic terms, it acts as the pressure that pushes charged electrons (known as the current) through an electric circuit. 

Great Britain’s National Grid system runs at a voltage of 400 kilovolts (kV) and 275kV (Scotland also uses 132kV). It is then reduced in a series of steps by transformers to levels suitable for supply to customers, for example 11kV for heavy industrial or 230 volts (V) when delivered to homes by regional distribution networks.

UK electricity voltage system

Keeping the voltage steady requires careful management. A deviation as small as 5% above or below can lead to increased wear and tear of equipment – and additional maintenance costs. Or even large-scale blackouts. Power stations such as Drax can control the voltage level through what’s known as reactive power.

“If voltage is high, absorbing reactive power back into the generator reduces it,” says Drax Lead Engineer Gary Preece. “By contrast, generating reactive power increases the voltage.”

Reactive power is made in an electricity generator alongside ‘active power’ (the electricity that powers our lights and devices) and National Grid can request generators such as Drax to either absorb or produce more of it as it’s needed to control voltage.

So how is a generator spinning at 3,000 rpm switched from producing to absorbing reactive power? All it takes is the turn of a tap.

Absorbing reactive power

Taps along a transformer allow a certain portion of the winding – which make up a transformer’s active part with the core – to be selected or unselected. This allows the transformer to alter what’s known as the ‘phase angle’, which refers to the relationship between apparent power (made up of reactive power and active power) and active power. This change in the phase angle regulates the ‘power factor’.

Power factor is measured between 0 and 1. Between 1 and 0 lagging means a generator is producing reactive power and increasing overall voltage, whereas between 1 and 0 leading means it is absorbing reactive power and reducing voltage.

That absorbed reactive power doesn’t just disappear, rather it transfers to heat at the back end of the power station’s generator. “Temperatures can be in excess of 60 degree Celsius,” says Preece. “There’s also a lot of vibration caused by the changes in flux at the end of the generator, this can cause long term damage to the winding.”

As the generators continue to produce active power while absorbing reactive power the conditions begin to reduce efficiency and, if prolonged, begin to damage the machines. Drax’s advantage here is that it operates six turbines, all of which are capable of switching between delivering or absorbing reactive power, or vice versa, in under two minutes.

UK electricity grid

Voltage management in a changing grid

The changing nature of Great Britain’s energy supply means voltage management is trickier than ever. Voltage creeps up when power lines are lightly loaded. The increase of decentralised generation – such as solar panels and small-scale onshore wind farms operating to directly supply specific localities or a number of customers embedded on regional electricity networks –  means this is becoming more common around the grid. This creates a greater demand for the kind of reactive power absorption and voltage management that Drax Power Station carries out.

Grid-scale batteries are being increasingly developed as a means of storing power from weather dependent renewable sources. This power can then be pumped onto the grid when demand is high. In a similar manner, these storage systems can also absorb reactive power when there’s too much on the system and discharge it when it’s needed – bringing the voltage down and up respectively.

Electricity storage

“The trouble is, grid-scale battery storage systems need to be absolutely huge, and a 100 MW facility would be close to the size of football field and double stacked,” explains Preece. “They are also not synchronised to the grid as a thermal turbine generator would be.” Subsequently there is no contribution to inertia.

As Great Britain’s power system continues to evolve, maintaining its stability also needs to adapt. Where once the challenge lay in keeping voltage high and enough reactive power on the grid, today it’s absorbing reactive power and keeping voltage down. It highlights the need for thermal generators that are designed to quickly switch between generating and absorbing to support the wider network.

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

Can we see electricity?

A 14th century carrack quietly sails through the currents of the Atlantic Ocean in the middle of the night. Its navigation relies on the stars shining above, its power on the wind blowing behind. It’s a far cry from the technologically advanced vessels sailing today’s seas.

It was here, long before civilisation began using and generating electricity, that the ghostly, blue-white glow of electricity acting upon air molecules was often seen as it hovered around ships’ masts.

This phenomenon is known as St. Elmo’s Fire, after Saint Erasmus of Formia – the patron saint of sailors – and occurs following thunderstorms when the electric field still present around an object (such as a lightning rod or a ship’s mast) causes air molecules to break up and become charged, creating what’s known as a plasma.

St. Elmo’s fire on a cockpit window

For sailors in an era long before satellite guidance it was a good omen. What they didn’t realise, however, was it was one of the rare instances when electricity acts in a way that changes it from an unseen force to something we can see, hear and even smell.

The science behind seeing electricity

Normally, we can’t see electricity. It’s like gravity – an invisible force we only recognise when it acts upon other objects. In the instance of electricity, the most common way it affects objects is by charging electrons, and because these are so small, so plentiful and move so quickly once charged, they are all but invisible to the naked human eye.

However, there are instances when conditions enable an electric current to conduct through the air, which can create sound and generate a visible plasma.

“You can see electricity in certain instances because it’s ionising the air,” says Drax Lead Engineer Gary Preece. In the process of ionising, the molecules that make up air become electrically charged, which can create a plasma.

“The electric current is able to bridge the air gap through the ionised air and to earth,” explains Preece. “You need to have that path to earth for it to create a spark.”

It’s a similar process to how a spark plug works or how lightning becomes visible. While there is still scientific debate around how clouds become electrically charged, the flashes seen on the ground are caused by discharges between clouds, or from clouds to the earth, creating a very hot and bright plasma.

The atmospheric conditions of our earth being largely oxygen and nitrogen give lightning a whitish-blue colour, like St. Elmo’s Fire. Altering these conditions so electricity passes through a gas such as neon changes the colour to a red-orangey shade, which is the principle on which neon lights and signs are built. To achieve different colours, different gases such as mercury and helium are used to fill the tube.

Long before we learned how to manipulate electricity to create different coloured signs we were battling with how to create visible, useful electricity. And it began with the use of arcs.

The architecture of electric arcs

Electric arcs occur when an electric current bridges an air gap. While air is an insulator, electricity’s constant attempts to conduct to earth sometimes enable it to find paths through it, ionising the air molecules and creating a visible plasma bridge along the way. The higher the voltage, the greater the distance it can arc between electrodes.

This property of electricity presents dangers such as arc ‘flashes’, which can occur during electrical faults or short circuit conditions and expel huge amounts of energy, sometimes creating temperatures as high as 35,000 degrees Fahrenheit – hotter than the sun’s surface.

When controlled, electrical arcs can be very useful. These bright glowing bridges were used in the first practical electric lights after Humphry Davy began showcasing the technology in the early 19th century.

But the need to replace carbon electrodes frequently, their buzzing sound and the resultant carbon monoxide emissions meant the technology was soon replaced with the incandescent bulb.

Today arcing is used in welding and in more sophisticated plasma cutting, which focuses a concentrated jet of hot plasma and can make highly precise cuts, while arc furnaces are used in industrial conditions such as steel making.

In fact, some thought has even gone into how we could use an incredibly powerful beam of plasma to create a working lightsabre. And although compelling, the theory of creating this super advanced Star Wars technology is far from being a practical possibility.

In the 14th century seeing electricity was a rare and positive omen. Today, seeing electricity has become far more common, yet when it does happen – through plasma spheres, neon lighting or naturally occurring lightning – the effect is the same: human wonder at seeing an awe-inspiring and seldom-seen force.

Is biomass demand out of control?

Electricity systems around the world are decarbonising and increasingly switching to renewable power sources. While intermittent sources, such as solar and wind, are the fastest growing types of renewables being installed globally, the reliability and flexibility of biomass and its ability to offer grid stabilisation services such as frequency control and inertia make it an increasingly necessary source of renewable power. According to the International Energy Agency biomass generation is forecast to expand as planned projects come online.

Sustainable wood pellets

A versatile resource

Biomass comes in many different forms.  When looking to assess future demand and use, it is important to recognise benefits that different types of biomass bring. Compressed wood pellets are just one small part of the biomass spectrum, which includes many forms of agricultural and livestock residues, waste and bi-products – much of which is currently discarded or underutilised.

Maximising the use of these wastes and residues provides plenty of scope for expansion of the biomass energy sector around the world. The global installed capacity for biomass generation is expected to reach close to 140 gigawatts (GW) by 2026, which will be fuelled primarily by expansion in Asia using residues from food production and the forestry processing industry.

However, the use of woody biomass can also provide many benefits too, such as supplying a market for thinnings, providing a use for harvesting residues, encouraging better forest management practices and generating increased revenue for forest owners.

How much surplus exists?

In areas like the US South, traditional markets for forest products have declined, whilst forest growth has significantly increased. According to the USDA Forest Inventory and Analysis (FIA) data, there is an average annual surplus of growth in the US South of more than 176 million cubic metres compared to removals – that’s enough to make around 84 million tonnes of wood pellets a year, from just one supply region.

Of course, not all of this surplus growth could or should be used for bio-energy, much of it is suitable for high value markets like saw-timber or construction and some of it is located on inaccessible or protected sites. However, new and additional markets are essential to maintain the health of the forest resource and to encourage forest owners to retain and maintain their forest assets.

In the current wood pellet supply regions for Europe, Pöyry management consulting has calculated that there is a surplus of low grade wood fibre and residues that could make an additional 140 million tonnes of wood pellets each year.

Wood pellets in context

Sustainable wood pellets for biomass

Compressed wood pellets on a conveyor belt

It is also necessary to look at the global production of all wood products to put wood pellet production into context. In 2016 the global production of industrial roundwood (the raw material used for construction, furniture, paper and other wood products) was 1.87 billion cubic metres, while the global production of wood fuel (used for domestic heating and cooking) was 1.86 billion cubic metres[1]. Only around 1.6% of this feedstock was used to make wood pellets, both for industrial energy and residential heat. The total production of wood pellets in 2016 was 28.4 million tonnes, of which only 45% was used for industrial energy[2].

While Forestry consulting and research firm Forisk predicts demand for industrial wood pellets (those used in electricity generation rather than residential heating) will grow globally at an annual rate of 15% for the next five years, reaching 27.5 megatonnes (Mt) by 2023, they are also clear that this growth, in context, will not impact forest volumes or other markets:

‘The wood pellet industry in the US South is not exploding, it is a tiny component of the overall market. Forest volumes in the South in total will continue to grow for decades no matter what bioenergy markets or housing markets do. The wood pellet sector simply and unequivocally cannot compete economically with US pulp and paper mills (80% of pulpwood demand in South) for raw material on a head-to-head basis[3].’

So, while demand for wood pellets is likely to increase over the next 10 years, this increase will be well within the scope of existing surplus fibre. The question, therefore, is can suppliers keep up with this demand? And can they do this while ensuring it remains sustainable, reliable and renewable?

What’s driving demand?

In the short-term, intelligence firm Hawkins Wright estimates global demand will increase by almost 30% during 2018 to reach 20.4 Mt, while Forisk predicts a smaller jump: an almost 5 Mt increase compared to 2017.

Most of this will continue to come from Europe (73% of global demand by 2021, more than 80% in 2018), where projects such as Lynemouth Power Station’s conversion from coal to biomass, as well as five co-firing units in the Netherlands are all set to come online very soon. While smaller in number, Asia is also developing a growing appetite for biomass and in 2018 demand is forecast to grow by 1.98 Mt.

These estimates might paint a picture of a continually soaring demand, but Forisk’s forecast actually expect this growth to plateau, levelling off around 2023 at 27.5 Mt. Hawkins Wright expects a similar slow down, forecasting manageable growth of under 15% between 2023 and 2026.

A forestry specialist at Drax Group, believes this plateau could come even sooner.

“Current and future forecasts in industrial wood pellet demand are based on a series of planned conversions and projects coming online,” he explains.

“But once these projects are active, demand in Europe will likely plateau around 2021 and then gradually reduce as various EU support schemes for industrial biomass come to an end. Any long term use of biomass is likely to be based on agricultural residues and wastes.”

But even with this expected slowdown, the biomass demand of the near future will be substantially higher than it is right now. So, the question remains, can suppliers meet the need for biomass pellets?

Responding to today’s growing demand

Meeting this growing demand depends on two factors: sufficient raw materials and the production capabilities to turn those materials into biomass pellets.

In today’s market, there’s no shortage of raw materials and low grade fibre. Instead, what could cause challenges is the production of pellets.

Hawkins Wright reports the capacity for global industrial pellet production was roughly 21.4 Mt a year at the end of 2017 and will increase by a further 3 Mt by 2019 as facilities currently under construction reach completion.

It means that to meet even Forisk’s conservative 27.5 Mt prediction by 2023, pellet production needs to increase. However, Drax’s specialist points to the three to four years needed to complete pellet facilities and the relatively short period of time financial support programmes will remain in place as something that could lead to a slowdown in new plants coming online. Instead, he says, expansions of existing plants and the increased use of small-scale facilities will become crucial to increasing overall production.

However the biomass market changes and develops, it remains critical that proper regulation is in place, efficiencies are found and that technological innovation continues within the forestry industry so forests are grown and managed sustainably.

As we move into a low-carbon future we know that biomass demand will increase. But for this to be truly beneficial and sustainable we need to ensure we are not only meeting the demand of today but also of tomorrow, the day after tomorrow and beyond.

Discover the steps we take to ensure our wood pellet supply chain is better for our forests, our planet and our future. Visit 

[1] Source: FAOSTAT

[2] Source: Hawkins Wright, The Outlook for Wood Pellets, Q4 2017


Why does electricity have a sound?

On cold, misty mornings, the powerlines, pylons and transformers that make up Great Britain’s electricity system sometimes sound a little different. Stand in a field under a powerline and, in the right conditions, the usual sounds of the countryside might be interrupted by the crackling of electricity.

This buzzing crackle, which can be referred to as a corona discharge, occurs when there’s a change from the normal conditions of a power line’s insulators enabling the electric current to partially conduct along it or through the surrounding air to earth. This can come as a result of weather conditions or deterioration of the insulators.

It’s just one of the instances where electricity changes from an unseen force powering our lights and devices to something we can hear, see and even smell.

Why can we hear electricity?

The source of electricity’s sound is also determined by one of its inherent properties: frequency. Frequency is the measurement of multiple occurrences from events, such as sound waves from vibrations, over a period of time. Any equipment that has a frequency causing mechanical parts to undergo repeated change can be audible.

For example, if we hit a cymbal with a drumstick we can hear a crash because of the frequency of the vibrations the mechanical part (in this case the cymbal) makes. We hear a guitar because its strings are plucked and pulled to create vibration at different frequencies. And we can hear an audible hum in a transformer because electric currents affect its internal structure and cause vibrations.

The buzzy tone this creates can be referred to as ‘mains hum’ and is ever present, although not always perceptible to the human ear. It becomes audible, however, when electricity (specifically alternating current – AC) is applied to a transformer.

Transformers are made of lengths of copper or aluminium, which are wound around a steel laminated core. When AC is applied it magnetises the core and causes steel laminations in the transformer to expand and contract in a process known as magnetostriction. Although only small physical changes, these movements are enough to cause vibration, which in turn creates an audible hum.

The crackling overhead

With more than 7,200 km of overhead powerlines humming away constantly around the country, corona discharges are inevitable and common.

This happens when part of the insulators on a high-voltage line begins to deteriorate, is exposed to weather conditions, is damaged or contaminated, allowing electricity to partially flow along it. The surrounding air becomes electrically charged through a process known as ionisation and causes molecules to become charged and collide.

It’s these collisions in the air that make the corona audible. It can also be visible and gives off a distinct smell of ozone, the gas produced when air is ionised.

Although not dangerous to someone on the ground below, if the insulator on the powerline is left to deteriorate further it can fail completely, leading to earth faults that trip power systems.

Making use of electric hums

The sounds electricity creates may seem like a nuisance but they can also have important uses. One of the most innovative applications is in forensic analysis.

A technique called Electric Network Frequency (ENF) enables forensic scientists to validate audio recording by observing the frequency of the mains hum picked up by audio recordings, which is not audible to humans.

By comparing the frequency of the hum in a recording to a database of the country’s frequencies at given times, it’s possible to verify when and in which country the recording took place and detect any editing.

It highlights not only an innovative use of electricity, but just how pervasive and consistent a presence it is. So, while the ebb and flow of electricity through our lives often goes on without thought, it is always there, humming away while it powers modern life in Great Britain.


8 technologies you never knew governments helped fund

There’s a common perception of how innovation happens: someone locked in a dark room has a lightbulb moment and with a finger click a world-changing idea is born.

This is true for the most part. Without people of immense passion, ambition and energy, we wouldn’t have much of the technology we take for granted today. But it doesn’t tell the whole story.

Many of the world’s most innovative technologies have come about thanks to great minds combined with institutional support. In fact, economist and author Mariana Mazzucato has argued that, of the 100 most important innovations from 1971 to 2006 (as identified by R&D Magazine), almost 90% depended heavily on government research support.


Although an inherent part of nearly every smart or connected device, Global Positioning System (GPS) technology wasn’t developed by a smartphone manufacturer like Apple or Samsung – it’s a product of the US Department of Defense.

In 1964, Roger Easton, a scientist at the US Naval Research Laboratory, began experimenting with satellite tracking to understand the path of satellites. In 1974, he was awarded a patent for a system which became GPS.

It was subsequently used by the US military to gain a more accurate understanding of the global position of its assets, but in 1998 US Vice President Al Gore announced a plan that would make GPS satellites transmit two additional signals that could be used for civilian means (for example, ensuring aircraft safety), leading the way for its inclusion in any number of devices.


Creator of the first commercially successful electric sports car and some of the most promising battery technology in the energy industry, Tesla is arguably one of the most exciting companies of the past few decades. Much of this is owed to the ground-breaking vision of its CEO, Elon Musk. However, it is equally indebted to early government support.

Telsa received a $465 million loan from the US Department of Energy in 2009, while two of Musk’s other companies SolarCity and SpaceX have also received substantial support. In total, Musk’s three companies have received $4.9 billion in US government support.

Jet engines

Today jet engines take millions of people around the world every minute, but before the Second World War they only existed in labs. While training for the Royal Air Force (RAF) in the late 1920s, Coventry-born engineer Frank Whittle outlined in a thesis the idea of using a gas turbine to propel a jet.

At the time he struggled to drum up any interest, with the UK’s Air Ministry believing the concept was impractical. Nevertheless, Whittle went on found his company Power Jets and prove his engine’s design in a lab in 1937.

With the political landscape in Europe becoming increasingly tense, the Air Ministry soon realised the potential importance of jet engines. It signed a contract in 1939 for Power Jets to develop an engine for aircraft manufacturer Gloster. 

The internet

One of the most important innovations of the last 50 years, the internet has its roots in the US military. In the 1960s, the Department of Defense developed a communication system that could directly link computers, called the ARPANET (Advanced Research Projects Agency Network).

This led to further development of computer-connecting systems, and in the mid 80s, British computer scientist Tim Berners-Lee, who at the time was working CERN, developed the Worldwide Web, leading to the increasingly connected world we know today.


 In 1959, Texas Instruments, one of the USA’s leading electronics companies, announced the launch of the integrated circuit – a small, self-contained circuit that didn’t require additional, disparate parts to function.

The potential of this early microchip was huge, but it was expensive to produce, which limited its growth. When the government realised it could use microchips to improve its missile and rocket guidance systems, it fuelled an increased demand that facilitated mass production of the new technology, and sparked the beginning of true growth.

The black box

In 1950, Australia’s Aeronautical Research Laboratory (ASL) was trying to figure out why British Comet aircraft were crashing. Chemist David Warren was researching fuels for newly-arrived jet engines, when he realised what ASL needed was not speculations on crashing Comets, but more data on what was happening inside the planes.

Development of the black box was gradual as it evolved from a simple tape recording of pilots’ conversation. The concept was even passed over by the Royal Australian Air Force.

It was a visit by Sir Robert Hardingham, the Secretary of the British Air Registration Board, in 1958 that eventually led to Warren presenting the idea at the UK’s Royal Aeronautical Establishment. Production of what we now know as a black box soon began in the UK.

Touch screens

Modern touchscreen technology was initially developed by the University of Kentucky, but it wasn’t until 1996, when the NSF and CIA began funding research at the University of Delaware, that the technology truly took off.

In 2001 the first touchscreen tablet was introduced by a company called FingerWorks, which was started by the University of Delaware research team. In 2005, Apple purchased their technology and adapted it to create the iPhone screen, which led to the technology’s ubiquity across many of the ‘smart devices’ we use today. 

Renewable and low carbon energy

Transforming an entire industry takes time. But when the matter is as urgent as decarbonising power generation on a national or global scale, government backing of the technologies making this possible is crucial. The electric revolution or ‘electricity era’ will positively impact heating, manufacturing, transport and other industries to lower their own carbon intensity.

The UK is aiming to drive adoption of renewable technologies and nuclear power through its Contracts for Difference (CfD) scheme. It works by generators being paid the difference between the ‘strike price’ – the cost of electricity with investment in the low-carbon technology factored in – and the market price to stabilise revenues for low-carbon suppliers.

An earlier scheme, the Renewables Obligation (RO), now closed to new projects in favour of CfDs, involves power generators receiving Renewable Obligation Certificates (ROCs) for every megawatt-hour (MWh) of electricity they generate. If they fail to meet their obligation to produce renewable power, they pay a penalty. CfDs allow for longer-term certainty, both for suppliers and consumers of power.

On a smaller scale, feed-in tariffs support adoption of renewable technologies by property owners with payments to cover the electricity it generates in excess of its own usage.

Encouraging investment

It’s not easy to get a new technology up and running – or to adapt and improve it to a challenge such as man-made climate change. The infrastructure investment, the supplier network, the manufacturing of multiple facilities all take time and investment. It often means companies at the vanguard of cutting edge industries need to spend a few years investing money before they and their shareholders stand to see any returns.

CfDs encourage businesses to secure their shareholders’ approval to commit capital over periods of a decade or more. Such investment has enabled wind, nuclear and biomass projects to get off the ground more quickly, whereas without a CfD, the upfront costs may have been prohibitive. Where flexible, low carbon biomass power generation at Drax is concerned, it’s providing certainty up to 2027, after which we hope to be able to operate subsidy-free.

The examples above show how early government support has been so critical in spurring commercial investment – and why it has played a large part in developing the industries and technologies we now see as innovative.

This process of innovation may be more than a lightbulb moment, but it does help keep the lights on.