Tag: national grid

How to count carbon emissions

Reduced demand, boosted renewables, and the near-total abandonment of coal pushed last quarter’s carbon emissions from electricity generation below 10 million tonnes.

Emissions are at their lowest in modern times, having fallen by three-quarters compared to the same period ten years ago.  The average carbon emissions fell to a new low of 153 grams per kWh of electricity consumed over the quarter.

The carbon intensity also plummeted to a new low of just 18 g/kWh in the middle of the Spring Bank Holiday.  Clear skies with a strong breeze meant wind and solar power dominated the generation mix.

Together, nuclear and renewables produced 90% of Britain’s electricity, leaving just 2.8 GW to come from fossil fuels.

The generation mix over the Spring Bank Holiday weekend, highlighting the mix on the Sunday afternoon with the lowest carbon intensity on record

National Grid and other grid-monitoring websites reported the carbon intensity as being 46 g/kWh at that time.  That was still a record low, but very different from the Electric Insights numbers.  So why the discrepancy?

These sites report the carbon intensity of electricity generation, as opposed to consumption.  Not all the electricity we consume is generated in Britain, and not all the electricity generated in Britain is consumed here.

Should the emissions from power stations in the Netherlands ‘count’ towards our carbon footprint, if they are generating power consumed in our homes?  Earth’s atmosphere would say yes, as unlike air pollutants which affect our cities, CO2 has the same effect on global warming regardless of where it is produced.

On that Bank Holiday afternoon, Britain was importing 2 GW of electricity from France and Belgium, which are mostly powered by low-carbon nuclear.  We were exporting three-quarters of this (1.5 GW) to the Netherlands and Ireland.  While they do have sizeable shares of renewables, they also rely on coal power.

Britain’s exports prevented more fossil fuels from being burnt, whereas the imports did not as they came predominantly from clean sources.  So, the average unit of electricity we were consuming at that point in time was cleaner than the proportion of it that was generated within our borders.  We estimate that 1190 tonnes of CO2 were produced here, 165 were emitted in producing our imports, and 730 avoided through our exports.

In the long-term it does not particularly matter which of these measures gets used, as the mix of imports and exports gets averaged out.  Over the whole quarter, carbon emissions would be 153g/kWh with our measure, or 151 g/kWh with production-based accounting.  But, it does matter on the hourly timescale, consumption based accounting swings more widely.

Imports and exports helped make the electricity we consume lower carbon on the 24th, but the very next day they increased our carbon intensity from 176 to 196 g/kWh.

When renewable output is high in Britain we typically export the excess to our neighbours as they are willing to pay more for it, and this helps to clean their power systems.  When renewables are low, Britain will import if power from Ireland and the continent is lower cost, but it may well be higher carbon.

Two measures for the carbon intensity of British electricity over the Bank Holiday weekend and surrounding days

This speaks to the wider question of decarbonising the whole economy.

Should we use production or consumption based accounting?  With production (by far the most common measure), the UK is doing very well, and overall emissions are down 32% so far this century.  With consumption-based accounting it’s a very different story, and they’re only down 13%*.

This is because we import more from abroad, everything from manufactured goods to food, to data when streaming music and films online.

Either option would allow us to claim we are zero carbon through accounting conventions.  On the one hand (production-based accounting), Britain could be producing 100% clean power, but relying on dirty imports to meet its entire demand – that should not be classed as zero carbon as it’s pushing the problem elsewhere.  On the other hand (consumption-based accounting), it would be possible to get to zero carbon emissions from electricity consumed even with unabated gas power stations running.  If we got to 96% low carbon (1300 MW of gas running), we would be down at 25 g/kWh.  Then if we imported fully from France and sent it to the Netherlands and Ireland, we’d get down to 0 g/kWh.

Regardless of how you measure carbon intensity, it is important to recognise that Britain’s electricity is cleaner than ever.

The hard task ahead is to make these times the norm rather than the exception, by continuing to expand renewable generation, preparing the grid for their integration, and introducing negative emissions technologies such as BECCS (bioenergy with carbon capture and storage).


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Front cover of Drax Electric Insights Q2 2020 report

Electric Insights Q2 2020 report [click to view/download]

The cost of staying in control

What: Industrial landscape with cables, pylons and train at sunset Where: Somerset, UK When: January 2016

The cost of keeping Britain’s power system stable has soared, and now adds 20% onto the cost of generating electricity.

The actions that National Grid takes to manage the power system have typically amounted to 5% of generation costs over the last decade, but this share has quadrupled over the last two years.  In the first half of 2020, the cost of these actions averaged £100 million per month.

Supplying electricity to our homes and workplaces needs more than just power stations generating electricity.

Supply and demand must be kept perfectly in balance, and flows of electricity around the country must be actively managed to keep all the interconnected components stable and prevent blackouts.  National Grid’s costs for taking these actions have been on the rise, as we reported over the previous two summers; but recently they have skyrocketed.

At the start of the decade, balancing added about £1/MWh to the cost of electricity, but last quarter it surpassed £5/MWh for the first time (see below).

Balancing prices have risen in step with the share of variable renewables.  The dashed line below shows that for every extra percent of electricity supplied by wind and solar adds 10 pence per MWh to the balancing price.  Last quarter really bucks this trend though, and balancing prices have risen 35% above the level expected from this trend.  The UK Energy Research Centre predicted that wind and solar would add up to £5/MWh to the cost of electricity due to their intermittency, and Britain has now reached this point, albeit a few years earlier than expected.

This is partly because keeping the power system stable is requiring more interventions than ever before.  With low demand and high renewable generation, National Grid is having to order more wind farms to reduce their output, at a cost of around £20 million per month.  They even had to take out a £50+ million contract to reduce the output from the Sizewell B nuclear reactor at times of system stress.

Two charts illustrating the costs of balancing Great Britain's power system

[Left] The quarterly-average cost of balancing the power system, expressed as a percentage of the cost of generation. [Right] Balancing price shown against share of variable renewables, with dots showing the average over each quarter

A second reason for the price rise is that National Grid’s costs of balancing are passed on to generators and consumers, who pay per MWh.  As demand has fallen by a sixth since the beginning of the coronavirus pandemic, the increased costs are being shared out among a smaller baseOfgem has stepped in to cap the balancing service charges at a maximum of £10/MWh until late October.  Their COVID support scheme will defer up to £100 million of charges until the following year.

For a quarter of a century, the electricity demand in GB ranged from 19 to 58 GW*.  Historically, demand minus the intermittent output of wind and solar farms never fell below 14 GW.  However, in each month from April to June this year, this ‘net demand’ fell below 7 GW.

Just as a McLaren sports car is happier going at 70 than 20 mph, the national grid is now being forced to operate well outside its comfort zone.

This highlights the importance of the work that National Grid must do towards their ambition to be ready for a zero-carbon system by 2025.  The fact we are hitting these limits now, rather than in a few years’ time is a direct result of COVID.  Running the system right at its limits is having a short-term financial impact, and is teaching us lessons for the long-term about how to run a leaner and highly-renewable power system.

Chart: Minimum net demand (demand minus wind and solar output) in each quarter since 1990

Minimum net demand (demand minus wind and solar output) in each quarter since 1990


Read full Report (PDF)   |  Read full Report   |   Read press release


Front cover of Drax Electric Insights Q2 2020 report

Electric Insights Q2 2020 report [click to view/download]

What are ancillary services?

Ancillary services

What are ancillary services?

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

Why do we need ancillary services? 

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

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

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

 What do ancillary services offer?

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

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

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

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

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

Key facts about ancillary services

Who manages ancillary services?

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

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

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

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

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

Ancillary Services

Ancillary services fast facts  

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

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

Go deeper

Button: What is decarbonisation?

Breaking circuits to keep electricity safe

Electric relay with sparks jumping between the contacts doe to breaking a heavy inductive load.

Electricity networks around the world differ many ways, from the frequency they run at to the fuels they’re powered by, to the infrastructure they run on. But they all share at least one core component: circuits.

A circuit allows an electrical current to flow from one point to another, moving it around the grid to seamlessly power street lights, domestic devices and heavy industry. Without them electricity would have nowhere to flow and no means of reaching the things it needs to power.

But electricity can be volatile, and when something goes wrong it’s often on circuits that problems first manifest. That’s where circuit breakers come in. These devices can jump into action and break a circuit, cutting off electricity flow to the faulty circuit and preventing catastrophe in homes and at grid scale. “All this must be done in milliseconds,” says Drax Electrical Engineer Jamie Beardsall.

But to fully understand exactly how circuit breakers save the day, it’s important to understand how and why circuits works.

Circuits within circuits 

Circuits work thanks to the natural properties of electricity, which always wants to flow from a high voltage to a lower one. In the case of a battery or mains plug this means there are always two sides: a negative side with a voltage of zero and a positive side with a higher voltage.

In a simple circuit electricity flows in a current along a conductive path from the positive side, where there is a voltage, to the negative side, where there is a lower or no voltage. The amount of current flowing depends on both the voltage applied, and the size of the load within the circuit.

We’re able to make use of this flow of electricity by adding electrical devices – for example a lightbulb – to the circuit. When the electricity moves through the circuit it also passes through the device, in turn powering it. 

A row of switched on household electrical circuit breakers on a wall panel

A row of switched on household electrical circuit breakers on a wall panel

The national grid, your regional power distributor, our homes, businesses and more are all composed of multiple circuits that enable the flow of electricity. This means that if one circuit fails (for example if a tree branch falls on a transmission cable), only that circuit is affected, rather than the entire nation’s electricity connection. At a smaller scale, if one light bulb in a house blows it will only affect that circuit, not the entire building.

And while the cause of failures on circuits may vary from fallen tree branches, to serious wiring faults to too many high-voltage appliances plugged into a single circuit, causing currents to shoot up and overload circuits, the solution to preventing them is almost always the same. 

Fuses and circuit breakers

In homes, circuits are often protected from dangerously high currents by fuses, which in Great Britain are normally found in standard three-pin plugs and fuse boxes. In a three pin plug each fuse contains a small wire – or element.

One electrical fuse on electronic circuit background

An electrical fuse

When electricity passes through the circuit (and fuse), it heats up the wire. But if the current running through the circuit gets too high the wire overheats and disintegrates, breaking the circuit and preventing the wires and devices attached to it from being damaged. When a fuse like this breaks in a plug or a fuse box it must be replaced. A circuit breaker, however, can carry out this task again and again.

Instead of a piece of wire, circuit breakers use an electromagnetic switch. When the circuit breaker is on, the current flows through two points of contact. When the current is at a normal level the adjacent electromagnet is not strong enough to separate the contact points. However, if the current increases to a dangerous level the electromagnet is triggered to kick into action and pulls one contact point away, breaking the circuit and opening the circuit breaker.

Another approach to fuses is using a strip made of two different types of metals. As current increases and temperatures rise, one metal expands faster than the other, causing the strip to bend and break the circuit. Once the connection is broken the strip cools, allowing the circuit breaker to be reset.

This approach means the problem on the circuit can be identified and solved, for example by unplugging a high-voltage appliance from the circuit before flipping the switch back on and reconnecting the circuit.

Protecting generators at grid scale 

Power circuit breakers for a high-voltage network

Circuit breakers are important in residential circuits, but at grid level they become even more crucial in preventing wide-scale damage to the transmission system and electricity generators.

If part of a transmission circuit is damaged, for example by high winds blowing over a power line, the current flow within that circuit can be disrupted and can flow to earth rather than to its intended load or destination. This is what is known as a short circuit.

Much like in the home, a short circuit can result in dangerous increases in current with the potential to damage equipment in the circuit or nearby. Equipment used in transmission circuits can cost millions of pounds to replace, so it is important this current flow is stopped as quickly as possible.

“Circuit breakers are the light switches of the transmission system,” says Beardsall.

“They must operate within milliseconds of an abnormal condition being detected. However, In terms of similarities with the home, this is where it ends.”

Current levels in the home are small – usually below 13 amps (A or ampere) for an individual circuit, with the total current coming into a home rarely exceeding 80A.

In a transmission system, current levels are much higher. Beardsall explains: “A single transmission circuit can have current flows in excess of 2,000A and voltages up to 400,000 Volts. Because the current flowing through the transmission system is much greater than that around a home, breaking the circuit and stopping the current flow becomes much harder.”

A small air gap is enough to break a circuit at a domestic level, but at grid-scale voltage is so high it can arc over air gaps, creating a visible plasma bridge. To suppress this the contact points of the circuit breakers used in transmission systems are often contained in housings filled with insulating gases or within a vacuum, which are not conductive and help to break the circuit.

A 400kV circuit breaker on the Drax Power Station site

A 400kV circuit breaker on the Drax Power Station site

In addition, there will often be several contact points within a single circuit breaker to help break the high current and voltage levels. Older circuit breakers used oil or high-pressure air for breaking current, although these are now largely obsolete.

In a transmission system, circuit breakers will usually be triggered by relays – devices which measure the current flowing through the circuit and trigger a command to open the circuit breaker if the current exceeds a pre-determined value. “The whole process,” says Beardsall, “from the abnormal current being detected to the circuit breaker being opened can occur in under 100 milliseconds.”

Circuit breakers are not only used for emergencies though, they can also be activated to shut off parts of the grid or equipment for maintenance, or to direct power flows to different areas.

A single circuit breaker used within the home would typically be small enough to fit in your hand.  A single circuit breaker used within the transmission system may well be bigger than your home.

Circuit breakers are a key piece of equipment in use at Drax Power Station, just as they are within your home. Largely un-noticed, the largest power station in the UK has hundreds of circuit breakers installed all around the site.

A 3300 Volt circuit breaker at Drax Power Station

A 3300 Volt circuit breaker at Drax Power Station

“They provide protection for everything from individual circuits powering pumps, fans and fuel conveyors, right through to protecting the main 660 megawatt (MW) generators, allowing either individual items of plant to be disconnected or enabling full generating units to be disconnected from the National Grid,” explains Beardsall.

The circuit breakers used at Drax in North Yorkshire vary significantly. Operating at voltages from 415 Volts right up to 400,000 Volts, they vary in size from something like a washing machine to something taller than a double decker bus.

Although the size, capacity and scale of the circuit breakers varies dramatically, all perform the same function – allowing different parts of electrical circuits to be switched on and off and ensuring electrical system faults are isolated as quickly as possible to keep damage and danger to people to a minimum.

While the voltages and amount of current is much larger at a power station than in any home, the approach to quickly breaking a circuit remains the same. While circuits are integral parts of any power system, they would mean nothing without a failsafe way of breaking them.

Why spin a turbine without generating power?

Turbine at Cruachan Power Station

Massive spinning machinery is a big part of electricity generation whether it’s a wind turbine, hydro plant or biomass generator.

But big spinning turbines don’t just pump electricity out onto the grid. They also play a crucial role in keeping the electricity system stable, safe and efficient. This is because big, heavy spinning turbines add something else to the grid: inertia.

This is defined as an object’s resistance to change but in the context of electricity it helps the grid remain at the right frequency and voltage level. In short, they help the grid remain stable.

However, as electricity systems in Great Britain and other parts of the world move away from coal and gas to renewables, such as wind turbines, solar panels and interconnectors, the level of inertia on the system is falling.

“We need the inertia, we don’t need the megawatts,” explains Julian Leslie, Head of Networks at the National Grid Electricity System Operator (ESO). “But in today’s market we have to supply the megawatts and receive the inertia as a consequence.”

Turbine at Drax Power Station

Engineer inspecting turbine blades at Drax Power Station

The National Grid ESO is taking a new approach to this aspect of grid stability by using what are called synchronous condensers. These complicated-sounding pieces of machinery are actually quite straightforward in their concept: they provide inertia to the grid without generating unnecessary power.

These come in the form of:

  • Existing generators that remain connected to the grid but refrain from producing electricity.
  • Purpose built machines whose only function is to act as synchronous condensers, never generating real power. These may be fitted with flywheels to increase their mass and, in consequence, their inertia.

This means that spinning without generating is about to become a very important part of Great Britain’s electricity system.

Around and around

Electricity generators that spin at 3,000 rpm are described as synchronous generators because they are in sync with the grid’s frequency of 50Hz. These include coal, gas, hydro, biomass turbines and nuclear units. Most spin at 3000 rpm, some machines much less (e.g. 750 rpm). Thanks to the way they are designed, they are all synchronised together at the same, higher speed.

Then there are wind turbines where the generated power is not synchronised to the grid system. Termed asynchronous generators, these machines do not have readily accessible stored energy (inertia) and do not contribute to the stability of the system. Interconnectors and solar panels are also asynchronous.

It’s important that Great Britain’s whole grid is kept within 1% of the 50Hz frequency, otherwise the voltage of electricity starts to fluctuate, damaging equipment, becoming less efficient, even dangerous, or resulting in blackouts.

Say a power station or a wind farm were to drop offline, as occurred in August 2019, this would cause the amount of power on the grid to suddenly fall. But it is not just the power that changes – the frequency and voltage also fluctuate dramatically which can cause equipment damage and ultimately, towns, cities or widespread areas to lose power.

Running machines that have inertia act like the suspension on a car – they dampen those fluctuations, so they are not as drastic. The big spinning machines keep spinning, buying valuable milliseconds for the grid to react, often automatically, before the damage becomes widespread.

However, as a consequence of decarbonisation, more solar panels and wind turbines are now on the system and there are fewer spinning turbines, leading to lower levels of inertia on the grid.

“There are periods when renewable generation and flow from interconnectors are so great that it displaces all conventional, rotational power plants,” says Leslie. “Today, bringing more inertia onto the grid may mean switching off renewables or interconnectors, and then replacing them with rotating plants and the megawatts associated with that.”

Creating a market for inertia and synchronous condensers offers a new way forward – providing inertia without unneeded megawatts or emissions from fossil fuels.

A new spin on grid stability

At the start of 2020, The National Grid ESO began contracting parties, including Drax’s Cruachan pumped-hydro power station, to operate synchronous condensers and provide inertia to the grid when needed.

The plans mark a departure from the previous system where inertia and voltage control from electricity generators was taken for granted.

Cruachan Power Station is already capable of running its units in synchronous condenser mode (one of its units, opened up for maintenance, is pictured at the top of this article). This involves an alternator acting as a motor, offering inertia to the grid without generating unneeded electricity. Other service providers will repurpose existing turbines, construct new machines or develop new technologies that can electronically respond to the grid’s need for stability.

Synchronous condensers, or the idea of spinning a turbine freely without generating power, are not new concepts; power stations in the second half of the 20th century could shut down certain generating units but keep them spinning online for voltage control.

In the 1960s and 70s, some substations – where the voltage of electricity is stepped up and down from the transmission system – also deployed stand-alone synchronous condensers. These were also used to provided inertia as well as voltage control but are long since decommissioned.

Synchronous condenser installation at Templestowe substation, Melbourne Victoria, Australia. By Mriya via Wikimedia.

“Synchronous condensers are a proven technology that have been used in the past,” says Leslie. “And there are many new technologies we are now exploring that can deliver a similar service.”

Cheaper, cleaner, more stable

Commercial UK wind turbines

The National Grid ESO estimates the technology will save electricity consumers up to £128 million over the next six years. Savings, which come from negating the need for the grid to call upon fossil fuels for inertia as coal, oil and gas, become increasingly uneconomical across the globe as carbon taxes grow.

The fact that synchronous condensers do not produce electricity also saves money the grid may have had to pay out to renewable generators to stop them producing electricity or to storage systems to absorb excess power.

“It means the market can deliver the renewable flow without the grid having to pay to restrain it or to pay for gas to stabilise the system,” says Leslie. “Not only does this allow more renewable generation, but it also reduces the cost to the consumer.”

In a future energy system, where there is an abundance of renewable electricity generations, synchronous condensers will be crucial in keeping the grid stable. The National Grid ESO’s investment in the technology further highlights the importance of new ideas and innovation to balance the grid through this energy transition.

Synchronous generation provides benefits to system stability beyond the provision of inertia. In a subsequent article we’ll also explore how synchronous condensers can assist with voltage stability and help regional electricity networks and customers to remain connected to the national system during and after faults.

Read about the past, present and future of the country’s electricity system in Could Great Britain go off grid? 

‘3D’ to drive an energy revolution

Think of the phrase ‘3D’ and may people instantly think of video games, television or cinema, along with the special glasses you needed to watch it.

But another form of 3D is, I believe, going to be at the heart of the energy revolution which is rapidly gathering place.

The three Ds in this case are Data, Diversification and Decarbonisation. Together, they will transform the way businesses buy, use and sell their energy, help companies take control of their energy use and save money and also play a key part in our journey towards a zero carbon, lower cost energy future.

We’re already seeing some real innovations in the energy sector. Our trial of a storage battery with a customer of Opus Energy is an example, offering a farming business in Northampton the chance to sell stored energy generated by solar panels back to the grid at times of peak demand – a potential new revenue stream.

But other innovations and advances will maintain the pace of change and data will be at the core of this now the new generation of smart meters are being installed in businesses, revolutionising customer relationships with their energy suppliers.

The data from the new meters will finally give customers insight into where and when they use energy. Suppliers will have to work much more closely with customers to help them access new opportunities for cost savings, access to new markets and even new revenue streams.

An example would be a restaurant. With the data smart meters will provide, the restaurant’s supplier will be able to tell the owners how their energy use compares to the local competition and where improvements can be made.

The detail could go as far as identifying whether the restaurant’s equipment is older and less efficient, whether rivals have installed newer kit or whether other businesses are switching off their equipment earlier or using it at different, cheaper times.

Using energy during the peak weekday morning and early evening hours is often the most expensive time to do so. Data will give businesses the insight into how they can use energy more efficiently and when they use it, offering them the chance to avoid buying at peak times whenever possible and driving efficiencies.

This is why Haven Power’s trading team is now working closely with GridBeyond. The partnership allows our customers to trade the power they produce as well as optimise their operations to help balance the grid at times of peak demand. The really smart thing is that in doing so, customers are reducing their energy costs and making their operations more sustainable.

Trading desks at Haven Power’s Ipswich HQ

The way demand changes and is managed by businesses and consumers on a diversified power system will also be key. The business energy sector is already diversifying as many customers are able to generate and store their own power but the next step is for more customers to be paid to reduce their usage at peak times.

Think of a busy time for the National Grid – half time in the FA Cup Final or after the results in Strictly Come Dancing. Previously, the grid would have to pay a power station to ramp up generation to meet demand but these days, customers are paid to reduce demand for 30 minutes or so – in effect becoming a huge virtual power station.

This has happened for some time of course with larger, industrial customers but now, smaller companies can benefit from this too, thanks to the data and insight they will have from their smart meters. This empowers customers and puts them, not the energy companies, in control of the key decisions about their energy.

A close, advisory relationship between energy suppliers and their customers will become ever more important to make sure business can choose to avoid the high demand periods, and maximises use during the lower, cheaper times. In fact, I can see a time when customers will end up paying more for insight and advice than they do for the power they buy – and they’ll save money overall in doing so.

And if we get all this right, it will help drive one of the most important of the three Ds – decarbonisation.

Sustainability is increasingly becoming a primary focus for businesses and demand for renewable energy is growing because it is now cost-effective. That will help us in our drive towards a zero carbon future as more and more renewable energy comes onstream, though the UK will continue to need power generated from more flexible assets as well.

So there are huge opportunities out there to transform our energy landscape but they have to be viewed positively. The smart metering programme can be viewed as a regulatory burden or it can be seen as an opportunity. We take the positive view.

Likewise, batteries were once the preserve of massive companies only but now, as technology develops, they are becoming available for smaller firms too. The more we can innovative on a larger scale, the more the technology will work its way into smaller markets too, adding momentum to the energy revolution.

The opportunities are huge. If we get it right, so too will be the benefits to one of the biggest priorities of all – the work to decarbonise the UK and create the lower carbon future we all want.

The history of the pylon

Pylons are one of the most recognisable and perhaps divisive symbols of Great Britain’s electricity system.

There are plenty who decry these metal giants as blotches strung across the country’s green and pleasant landscape. But time has turned the 1930s designs of Great Britain’s pylons into something of a modernist classic, even beloved by some.

What pylons symbolise, however, is more than just the modernisation of the country in the first half of the 20th century. They also represent the promise of safe and reliable electricity for all. There are now more than 90,000 pylons across Great Britain and while the energy system continues to evolve, pylons have changed little since they first went up outside Edinburgh in the 1920s. 

Miesbach to Munich

The first successful attempt to transmit electricity over long distances using overhead wires took place in 1882. German engineer Oskar von Miller and his French colleague Marcel Deprez successfully transmitted 2.5 kilowatts of electricity 57km along a telegraph line.

The simple iron line transmitted a 200 volt current from a steam engine-powered generator near Miesbach to the glass palace of Munich, where it was used to power the motor for an artificial waterfall. The line failed a few days later, and even though it may be a world away from today’s 800,000 volt ultra-high voltage transmission lines, this first trial laid the foundation for the way we move energy today.

Egypt to Edinburgh

Jump to 1928 and there was something new arising on Edinburgh’s horizon. The first “grid tower” was erected here on July 14th as part of the recently established Central Electricity Board’s ambitious project to create a “national gridiron”.

Connecting 122 of Great Britain’s most efficient power stations to consumers was a mission that required 4,000 miles of cables, mostly overhead. Sir Reginald Blomfield was called in to tackle this grand challenge.

Blomfield adopted a design submitted by the American firm Milliken Brothers for the “grid towers” that would criss-cross the country. A staunch anti-modernist – as he made clear in Modernismus, his attack on modern architecture – Blomfield looked to ancient Egypt to name his steel towers.

In Egyptology, a pylon is a gateway with two monumental towers either side of it. These represented two hills between which the sun rose and set, with rituals to the sun god Ra often carried out on the structures. It was an epic name to match the grand ambitions of creating a national grid.

By September 1933 the last of the initial 26,000 pylons that made up the National Grid were installed, less than a third of the 90,000 that make up the system today. The grid was now ready to operate, on time and on budget.

Around the world to underground

As the energy system continues to evolve Great Britain’s pylons are changing too. In 2015, the National Grid unveiled a new Danish-designed pylon that shifts away from the classic industrial tower to a T-framed ski-lift style model designed to minimise the visual impact of the pylons on the landscape.

Another approach also being adopted is burying cables underground. The process of digging tracts and burying cables for thousands of miles could cost as much as £500 million but could help preserve areas of natural beauty while ensuring the whole country has access to the safe and reliable electricity it has come to expect.

As with all change, these announcements have caused a surge in nostalgia for the pylon remembered from childhood car journeys across the country.

Around the globe electricity pylons are now ubiquitous and are being pushed to new technological limits. In 1993 Greenland became home to the longest stretch of overhead powerline between pylons in the Ameralik Span, while China’s Zhoushan Island Overhead Powerline Tie set the record for the world’s tallest pylons in 2010 with two 370-meter towers.

Despite the advancements, it’s notable how little these structures have changed from the those first installed around the world. The proposed humanoid sculptures of Icelandic architecture firm Choi+Shine bare a resemblance to the original skeletal towers of the 30s. And it shows just how successful those original pylons have been at delivering much-needed electricity to homes and businesses around the country.

Power and the rise of electric cars

Power supply for electric car charging. Electric car charging station. Close up of the power supply plugged into an electric car being charged.

All great technological innovations need infrastructure to match. The world didn’t change from candles to lightbulbs overnight – power stations had to be built, electricity cables rolled out, and buildings fitted with wiring. The same is true of electric vehicles (EV).

Think of the number of petrol stations lining the UK roads. If EVs continue their rise in popularity, the country will need electric car-charging facilities to augment and then replace these petrol stations.

This could mean big extensions of electricity grid infrastructure, both in the building of new power generation capacity to meet demand, and in the extension of the networks themselves.

In short, it could mean a significant change in how electricity is used and supplied.

The need for better electricity infrastructure

In 2013, only 3,500 of newly registered cars in the UK were plug-in electric or hybrid EVs. In 2016, that number jumped to 63,000. Their use is rising rapidly, but the lack of infrastructure has kept a cap on the number of EVs on UK roads. That is starting to change.

As of 2019, all new and refurbished houses in the EU will have to be fitted with an electric car charging point, according to a draft directive announced by Brussels. The UK will probably no longer be an EU member by the time the directive comes into effect, but nevertheless, the UK government is pursuing its own ways to account for the rise of EVs. It has pledged more than £600 million between 2015 and 2020 to support ultra-low-emission vehicles – £38 million of this has already been earmarked for public charging points.

There are more innovative responses to EV rise, too. Nissan, in partnership with Italian energy provider Enel, has announced it will install around one hundred ‘car-to-grid’ charging points across the UK. With their innovative V2G technology, cars plugged into these sites will be able to both charge their batteries and feed stored energy back to the National Grid when necessary. So when there is a peak in demand, the Grid could access the cars’ stored energy to help meet it.

The total capacity of the 18,000 Nissan electric vehicles currently operational on UK roads comes to around 180 MW. So even today – before electric vehicles have really taken off – this could give the National Grid an additional supply roughly the size of a small power station.

Peaks in electricity demand, however, tend to occur in the late afternoon or evening as it gets dark and more lighting and heating gets switched on. This also happens to be rush hour, so under this scheme the time of day the cars are most likely to be on the roads is also when it’d be most helpful to have them plugged in. This could lead to financial incentives for people to give up the flexibility of driving their cars only when they need to.

Power supply for electric car charging. Electric car charging station.

More electric cars, more demand for electricity, more pollution?

More EVs on the road makes sound environmental sense – they enable a 40% reduction in CO2 emissions – but ultimately the energy still has to come from somewhere. That means more power stations.

The scale of this new demand shouldn’t be underestimated: if European drivers were to go 80% electric, some studies have suggested it would require 150 GW of additional on-demand capacity – the equivalent of 40 Drax-sized power stations.

But if EVs are to live up to their green potential, that additional power needs to come from innovations in storage (such as in the Nissan example) and from renewable sources like wind, solar and biomass. Fossil fuels would ideally be used only to plug any gaps that intermittency creates – for example by briefly firing up the small gas power stations Drax plans to build in England and Wales.

What does this mean for generators?

Drax, as operator of the UK’s largest biomass power station and with plans for new, rapid response open cycle gas turbines (OCGTs), is well placed to be at the forefront of providing reliable, affordable power in the event of a widespread rollout of electric vehicles. The OCGTs in particular, are designed for use in peak times which, in the future, could be when the nation’s electric vehicles are plugged in overnight – today this is when electricity demand is at its lowest.

A future of more electric cars is a positive one. They’re cleaner, more efficient, and they are well suited to our increasingly urban lives. But now that we have the technology, we need to ensure we can deliver the lower-carbon infrastructure they need.