Tag: power station

9 of the biggest TV moments in UK electricity history

1 August 2022

Power generation

It’s 1990 and Chris Waddle, England midfielder, steps up to the penalty spot. The 60,000 people in Turin’s Stadio delle Alpi watching him and the fate of England football go silent.

He takes a breath and fires a shot at Bodo Illgner, the German goalkeeper. It careers over the crossbar and misses – England are out of the World Cup. The now famous image of Paul Gascoigne crying into his shirt is beamed across millions of UK television screens.

There’s a shuffling on the sofas in front of those TVs as the population gets up to make a cup of tea, get a drink or turn on the oven. Millions of kettles, lights and fridges are powered up as the country collectively despairs. The demand for electricity across the country soars.
kettle boiling
This is what’s called a ‘TV pickup’ – the moment during a popular television event when there’s a break and viewers unwittingly cause a huge surge of demand from the National Grid.

It’s these moments that have caused some of the biggest spikes in UK electricity demand. Here we look at what’s caused them:

One:

What? Football World Cup Semi Final: England v West Germany
When? Wednesday, 4 July 1990
Electricity demand: 2,800MW – equivalent to 1,120,000 kettles (based on 1MW = 400 kettles), or 4.3 Drax-sized generation units (there are six 645MW units at Drax)

After that fateful penalty miss the population made for the kitchen. The match was watched by an estimated 26 million people in the UK, and when full time was called they caused a 2,800MW surge in electricity demand.

Two:

What? The Thorn Birds
When? 22 January 1984
Electricity demand: 2,600MW – 1,040,000 kettles – 4 Drax units

A sleeper hit, The Thorn Birds was a one-off American mini-series about a fictional sheep station in the Australian outback. Based on the novel of the same name, it was broadcast in the UK following building up a huge following in the US when it was aired in 1983. By the time it arrived on UK shores there was clearly enough of that excitement to create a surge of electricity demand – one of the largest in UK TV history.

Three:

What? Football World Cup Quarter Final: England v Brazil
When? Friday, 21 June 2002
Electricity demand: 2,570MW – 1,028,000 kettles – 4 Drax units

Broadcast early on a Wednesday morning in the UK due to time differences with South Korea, where the game was played, the match saw England put up a solid fight against overall tournament winners Brazil. A goal from Michael Owen provided early hope and at half time TV viewers left their screens to cause a huge 2,570MW spike in demand. By the time the game had reached its conclusion, Brazil had won thanks to a chipped Ronaldinho free kick that fooled England keeper David Seaman and those viewers who had lasted the duration caused a slightly smaller 2,300MW surge.

Sad couple watching football match on television at home.Four:

What? Eastenders: Lisa admits shooting Phil
When? Thursday, 5 April 2001
Electricity demand: 2,290MW – 916,000 kettles – 3.5 Drax units

In one of the most dramatic plot developments in UK TV history, Lisa Shaw, played by actress Lucy Benjamin, admitted to shooting her former boyfriend, Phil Mitchell. An estimated 22 million viewers turned on to see the dramatic reveal. When it was all over they caused a surge of 2,290MW, more than five times the normal pickup of 400MW seen at the end of an average Eastenders episode.

Five:

What? The Darling Buds of May
When? Sunday, 12 May 1991
Electricity demand: 2,200MW – 880,000 kettles – 3.4 Drax units

One of the more wholesome entries to the list, this British comedy drama racked up a huge following during its 20-episode run from 1991 to 1993. The peak was early in the first season, when the third ever episode saw the Larkin family take an unhappy holiday to Brittany. The family’s escapades drew a large audience and prompted a surge equivalent to 880,000 kettles being switched on at the same time.

Six:

What? Rugby World Cup Final: England v Australia
When? Saturday, 22 November 2003
Electricity demand: 2,110MW – 844,000 kettles – 3.3 Drax units

A unique sporting entry to the list as England ended as winners. More than 12 million people watched England beat Australia, with the largest electricity demand coming at half time and not at full time, when audiences were presumably still celebrating Jonny Wilkinson’s last minute drop goal.

Seven:

What? European Football Championship 2020 final: England vs Italy
When? Sunday, 11 July 2021
Electricity demand: 1,800MW – 720,000 kettles – 2.8 Drax units

The most recent heartbreaker for England fans, the match came as COVID-19 restrictions were only beginning to lift around the UK. The team, led by Gareth Southgate, conquered old foes Germany on their way to a final in Wembley, only to lose to Italy on penalties.

The sense of disappointment was almost palpable in the energy demand, peaking at 1,800MW at half-time, when England went into the changing rooms one-nil up. Demand then surged again to 1,200MW at the end of the 90-minute stalemate, followed by a deflated 500MW at the end of the game. Had things gone differently, National Grid ESO was preparing for a peak of 2,000MW.

Eight:

What? The Royal Wedding – Prince William and Kate
When? Friday, 29 April 2011
Electricity demand: 1,600MW – 640,000 kettles – 2.5 Drax units

The biggest and most celebrated Royal Wedding in a generation, the marriage of Prince William and Kate Middleton attracted an audience of 24 million in the UK alone. Energy demand peaked at 1,600MW when the bride’s carriage procession returned to Buckingham Palace. This is the largest TV pickup in recent years, which hints at how changing viewer habits, on demand watching and smart TVs are changing the need for power and making TV pickups a rarer occurrence.

Nine:

What? Clap for carers
When? Thursday, 16 April 2020
Electricity demand: 950MW – 320,000 kettles – 1.5 Drax units

COVID-19 and subsequent lockdowns had several interesting effects on the UK’s energy system. One feature was a return in regular demand spikes, with Thursday evenings’ Clap for Carers events prompting notable surges.

The gestures, held at 8pm on Thursdays between 26 March and 28 May 2020, saw millions across the UK stand outside their homes and clap in appreciation of emergency services workers. As people went back inside to put on kettles and turn on TVs electricity demand spiked. The particularly cloudy evening of 16 April saw demand reach 950MW as more people reached for light switches.

How do we deal with TV pickups?

National grid electricty pylon at sunrise

Because the level of electricity needed to power the country can’t be stored, when there is a spike in demand it needs to be met quickly by a similar increase in real time generation.

To manage the supply and demand for events likely to cause electricity surges, the National Grid forecasts electricity need for large events like World Cups and major TV events.

The grid can then put contingency measures in place to manage the huge changes in demand in real time. It does this through a suite of tools called balancing mechanisms, which allows it to access sources of extra power in real-time.

The rise of more energy efficient home appliances and on-demand streaming means that the ‘shape’ of electricity demand has become flatter since the days when most of the country was tuned into the same must-see moments.

However, it’s still crucial for the grid to forecast periods of high demand, when it will keep the necessary power stations on reserve, ready to deliver additional electricity if needed.

If it wasn’t for this careful management of electricity by the grid and the power stations like Drax supplying it, that cup of tea next time England crash out of a major sporting event would not only be tainted with disappointment but cold, too.

14 moments that electrified history

13 May 2020

Electrification

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

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

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

500 BC – The discovery of static electricity

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

1600 AD – The origins of the word ‘electricity’

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

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

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

1765 – James Watt transforms the Industrial Revolution

Watt studies Newcomen’s engine

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

James Watt’s steam engine

Alessandro Volta

1800 – Volta’s first true battery

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

1800s – The first electrical cars

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

Michael Faraday

1831 – Michael Faraday’s electric dynamo

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

1879 – Lighting becomes practical and inexpensive

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

Holborn Viaduct power station via Wikimedia

1882 – The world’s first public power station opens

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

1880s – Tesla and Edison’s current war

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

Inside an Edison power station in New York

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

Nikola Tesla

1901 – Great Britain’s first industrial power station opens

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

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

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

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

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

6 disused power stations renovated and reimagined

23 January 2020

Power generation
E-WERK entrance

The Tate Modern and Battersea Power Station along the banks of the Thames are architectural icons of the London skyline. But before they were landmarks, they were oil- and coal-burning power stations, right in the heart of the city they powered.

As the city developed, the technology used to generate power advanced, and the need for cleaner fuel sources grew, the requirement for large, city-based fossil fuel power stations like these fell. The closure of Battersea and the Bankside power stations became inevitable.

Rather than knocking them down, however, it was clear their scale, heritage and location could be repurposed to meet an entirely new set of needs for the city. Now, as an art gallery and modern, mixed-use neighbourhood space, they remain in service to the city while retaining part of their heritage.

Eindhoven’s Innovation Powerhouse, Netherlands

Eindhoven’s Innovation Powerhouse, Netherlands. Photo: Tycho Merijn.

The reimagining of disused power stations is not just a London phenomenon. It is one seen around the world, where industrial buildings like these are being transformed for a range of purposes.

Eindhoven’s Innovation Powerhouse

Eindhoven’s Innovation Powerhouse in the Netherlands remains distinguishable as a power station due to its enormous coal chimneys, but today it serves a different purpose. The original skeleton of the building has been repurposed as a creative office space for innovative tech companies. The open plan structure encourages collaboration and creativity and its location right in the city centre makes it easily accessible to employees. In a nod to its previous use, however, a biogas plant remains situated next door, burning wood waste to produce renewable electricity and heat for the building.

Beloit’s cultural ‘Powerhouse’

Like Innovation Powerhouse, the exterior of Blackhawk Generating Station in Beloit, Wisconsin remains clearly identifiable as a power station. A century ago the once gas-fired plant supplied peak-time electricity to surrounding cities, but since being bought by Beloit University, it’s being transformed into ‘The Powerhouse’– a leisure and cultural centre for both students and the general public. Designs include an auditorium, a health and wellness hub, a swimming pool, lecture halls and more. It sits along the Rock River, between the university and the city – a prime location for bringing communities together, and is due to open in January 2020.

CGI of The Powerhouse, Beloit College Wisconsin. Image: Studio Gang Architects

An artist’s impression of The Powerhouse, Beloit College Wisconsin. Photo: Studio Gang Architects.

The Tejo Power Station Electricity Museum, Lisbon, Portugal.

Lisbon’s electricity museum

The Tejo Power Station once supplied electricity to the whole of Lisbon. Today it’s a museum and art gallery, but remains a testament to Portugal’s technological, historical and industrial heritage. It pays homage to the evolution of electricity through a permanent collection that includes original machinery from its construction in 1908, and charts its evolution from baseload electricity generator to standby power station used only to complement the country’s prominent supply of hydro plants. It’s a space that celebrates the heritage of the building, an attitude reflected throughout Portugal – there is even an energy museums roadmap created for people to tour a trail of decommissioned power stations.

Rome’s renaissance power station

Centrale Montemartini Thermoelectric plant was Rome’s first public power station, operating between 1912-1963. Decommissioned in the 1960s, it was adapted to temporarily house an exhibition of renaissance sculptures and archaeological finds from Rome’s Capitoline Museums that were at the time undergoing renovation. The clash of the classical artworks and the power station’s original equipment was such a success that it has been open ever since.

Centrale Montemartini, Rome, Italy.

Berlin’s E-WERK Luckenwalde

Why replace a power station with an art gallery if it could in fact be both? Berlin’s E-WERK Luckenwalde is a hybrid – what was once a coal power plant before the collapse of communism in 1989, is now both a renewable power plant and an art gallery. It uses waste woodchips from neighbouring companies to generate and sell power to the grid to fund the cost of a contemporary art centre housed inside it. It still generates electricity, only this time it’s renewable and powers the art gallery, which in turn energises the artistic community of Berlin.

 

Copenhagen’s futuristic Amager Bakke Waste-to-Energy-Plant

 Copenhagen’s Amager Bakke Waste-to-Energy-Plant is one of the cleanest incineration plants in the world. Opened in 2017 to replace a nearby 45-year-old incineration plant, it burns municipal waste to create heat and power for the surrounding area. What really sets it apart, however, is its artificial ski slope cascading down one side of the building, which has been open to the public all year-round since October 2019. This purposefully bold design sets out to change people’s perceptions of what power stations can do.

CopenHill ski slope, Amager Bakke, Copenhagen, Denmark. Photos: Max Mestour.

CopenHill ski slope, Amager Bakke, Copenhagen, Denmark. Photos: Max Mestour.

The decommissioning of power stations has resulted in cities’ acquiring buildings in prime central locations for the public to enjoy. These examples demonstrate the world’s transition to renewable power, the advances of technology, and populations’ increasing awareness of the environmental impact of their energy usage.

Top image: Entrance of E-WERK Luckenwalde, 2019. Photo: Ben Westoby. Click here to view/download. 

How Scotland’s sewage becomes renewable energy

17 December 2019

Sustainable bioenergy
Stevie Gilluley Senior Operator at Daldowie fuel plant

From traffic pollution to household recycling and access to green spaces, cities and governments around the world are facing increasing pressure to find solutions to a growing number of urban problems.  

One of these which doesn’t come up often is sewage. But every day, 11 billion litres of wastewater from drains, homes, businesses and farms is collected across the UK and treated to be made safe to re-enter the water system.   

Although for the most part sewage treatment occurs beyond the view of the general population, it is something that needs constant work. If not dealt with properly, it can have a significant effect on the surrounding environment.  

Of the many ways that sewage is dealt with, perhaps one of the most innovative is to use it for energy. Daldowie fuel plant, near Glasgow is one such place which processes sewage sludge taken from the surrounding area into a renewable, low carbon form of biomass fuel.  

The solution in the sludge   

In operation since 2002, Daldowie was acquired by Drax at the end of 2018 and today processes 35% of all of Scotland’s wastewater sludge, into dry, low-odour fuel pellets.   

“We receive as much as 2.5 million tonnes of sludge from Scottish Water a year,” says Plant Manager Dylan Hughes who leads a team of 71 employees, “And produce up to 50,000 tonnes of pellets, making it one of the largest plants of this kind in the world.”  

“We have to provide a 24/7, 365-day service that is built into the infrastructure of Glasgow,” he explains.   

This sludge processed at Daldowie is not raw wastewater, which is treated in Scottish Water’s sewage facilities. Instead, the sludge is a semi-solid by-product of the treatment process, made of the organic material and bacteria that ends up in wastewater from homes and industry, from drains, sinks and, yes, toilets.   

Until the late 1990s, one of Great Britain’s main methods of disposing of sludge was by dumping it in the ocean. After this practice was banned, cities where left to figure out ways of dealing with the sludge.   

Using sludge as a form of fertiliser or burying it in landfills was an already established practice. However, ScottishPower, instead decided to investigate the potential of turning sludge into a dry fuel pellet, that could offer a renewable, low carbon substitute to coal at its power plants. 

Cement manufacturing fuel kilns

Daldowie was originally designed to supply fuel to Methil Power Station near Fife, which ran on coal slurry. However, it was decommissioned in 2000, before Daldowie could begin delivering fuel to it. This led the plant to instead provide fuel to Longannet Power Station where it was used to reduce its dependency on coal, before it too was decommissioned in 2016. 

Today Daldowie’s pellets are used in England and Scotland to fuel kilns in cement manufacturing – an industry attempting to navigate the same decarbonisation challenges as power generation which Daldowie was established to tackle.  

Though the end use of the fuel has changed, the process through which the facility transforms the waste remains the same.  

The process of turning waste to energy  

The process starts after wastewater from Glasgow and the surrounding area is treated by Scottish Water. Daldowie receives 90% of the sludge it processes directly via a pressurised sludge pipeline, the rest is delivered via sealed tanker lorries.   

When it arrives at Daldowie, the sludge is 98% water and 2% solid organic waste. It is first screened for debris before entering the plant’s 12 centrifuges, which act as massive spinning driers. These separate water from what is known as ‘sludge cake’, the semi-solid part of the sludge feedstock. This separated water is then cleaned so it can either be used elsewhere in the process or released into the nearby River Clyde. 

Membrane Tank at Daldowie fuel plant

The remaining sludge cake is dried using air heated to 450 degrees Celsius using natural gas (this also reduces germs through pasteurisation), while the rotating drums give the fuel granules their pellet shape. Once dried the pellets are cooled and inspected for quality. Any material not up to necessary standards is fed back into the system for reprocessing. Fuel that does meet the right standards is cooled further and then stored in silos.   

Where possible throughout the process, hot air and water are reused, helping keep costs down and ensuring the process is efficient.  

Nearly two decades into its life, very little has had to change in the way the plant operates thanks to these efficiencies. But while the process of turning the waste sludge into energy remains largely unchanged, there is, as always, room for new innovation.  

 Improving for the future of the site 

Daldowie is contracted to recycle wastewater for Scottish Water until 2026. To ensure the plant is still as efficient and effective as possible, the Daldowie team is undertaking a technical investigation of what, if anything, would be needed to extend the life of the plant for at least an additional five years. 

“The plant operates under the highest environmental and health and safety standards but further improvements are being planned in 2020.” Hughes explains, “We are upgrading the odour control equipment to ensure we have a best in class level of performance.  

The control room and plant operators at Daldowie

“Drax’s Scotland office, in Glasgow, is working with other industrial facilities in the area, as well as the Scottish Environmental Protection Agency (SEPA), to work with the local community. We are putting in place a series of engagement events, including plant tours from early 2020, offering local residents an opportunity to meet the local team and discuss the planned improvements.”    

There are also other potential uses for the fuel, including use at Drax Power Station. As the pellets are categorised as waste and biomass, it would require a new license for the power station.  

However, at a time when there is a greater need to reduce the impact of human waste and diversify the country’s energy, it would add another source of renewable fuel to Great Britain’s electricity mix that could help to enable a zero carbon, lower cost energy future.  

What makes a mountain right for energy storage

22 May 2019

Power generation
Cruachan pylons

Electricity generation is often tied to a country’s geography, climate and geology. As an island Great Britain’s long coastline makes off-shore wind a key part of its renewable electricity, while Iceland can rely on its geothermal activity as a source of power and heat.

One of the most geographically-influenced sources of electricity is hydropower. A site needs a great enough volume of water flowing through it and the right kind of terrain to construct a dam to harness it. Even more dependent on the landscape is pumped hydro storage.

Pumped storage works by pumping water from one source up a mountain to a higher reservoir and storing it. When the water is released it rushes down the same shafts it was pumped up, spinning a turbine to generate electricity. The advantage of this is being able to store the potential energy of the water and rapidly deliver electricity to plug any gaps in generation, for example when the wind suddenly dropsor when Great Britain instantly requires a lot more power.

This specific type of electricity generation can only function in a specific type of landscape and the Scottish Highlands offers a location that ticks all the boxes.

The perfect spot for pumped storage

Cruachan Power Station, a pumped hydro facility capable of providing 440 megawatts (MW) of electricity, sits on the banks of Loch Awe in the Highlands, ready to deliver power in just 30 seconds.

“Here there is a minimum distance between the two water sources with a maximum drop,” says Gordon Pirie, Civil Engineer at Cruachan Power Station, “It is an ideal site for pumped storage.”

The challenge in constructing pumped storage is finding a location where two bodies of water are in close proximity but at severely different altitudes.

From the Lochside, the landscape rises at a dramatic angle, to reach 1,126 metres (3,694 feet) above sea level at the summit of Ben Cruachan, the highest peak in the Argyll. The crest of Cruachan Dam sits 400.8 metres (1,315 feet) up the slopes, creating a reservoir in a rocky corrie between ridges. The four  100+ MW turbines, which also act as pumps, lie a kilometre inside the mountain’s rock.

“The horizontal distance and the vertical distance between water sources is what’s called the pipe-to-length ratio,” explains Pirie. “It’s what determines whether or not the site is economically viable for pumped storage.”

The higher water is stored, the more potential energy it holds that can be converted into electricity. However, if the distance between the water sources is too great the amount of electricity consumed pumping water up the mountain becomes too great and too expensive.

The distance between the reservoir and the turbines is also reduced by Cruachan Power Station’s defining feature: the turbine hall cavern one kilometre inside the mountain…

Carving a power station out of rock

The access tunnel, cavern and the networks of passageways and chambers that make up the power station were all blasted and drilled by a workforce of 1,300 men in the late 1950s to early 1960s, affectionately known as the Tunnel Tigers.

This was dangerous work, however the rock type of the mountainside was another geographic advantage of the region. “It’s the diorite and phyllite rock, essentially granite, so it’s a hard rock, but it’s actually a softer type of granite, and that’s also why Cruachan was chosen as the location,” says Pirie.

The right landscape and geology was essential for establishing a pumped storage station at Cruachan, however, the West Highlands also offer another essential factor for hydropower: an abundance of water.

Turning water to power

The West Highlands are one of the wettest parts of Europe, with some areas seeing average annual rain fall of 3,500 millimetres (compared to 500 millimetres in some of the driest parts of the UK). This abundance of water from rainfall, as well as lochs and rivers also contributes to making Cruachan so well-suited to pumped storage.

The Cruachan reservoir can contain more than 10 million cubic metres of water. Most of this is pumped up from Loch Awe, which at 38.5 square kilometres is the third largest fresh-water loch in Scotland. Loch Awe is so big that if Cruachan reservoir was fully released into the loch it would only increase the water level by 20 centimetres.

However, the reservoir also makes use of the aqueduct system made up of 19 kilometres of tunnels and pipes that covers 23 square kilometres of the surrounding landscape, diverting rainwater and streams into the reservoir. Calculating quite how much of the reservoir’s water comes from the surrounding area is difficult but estimates put it at around a quarter.

“There are 75 concrete intakes dotted around the hills to gather water and carry it through the aqueducts to the reservoir,” says Pirie. “The smallest intake is about the size of a street drain in the corner of a field and the largest one is about the size of a three-bedroom house.”

Pumped storage stations offer the electricity system a source of extra power quickly but it takes the right combination of geographical features to make it work. Ben Cruachan just so happens to be one of the spots where the landscape makes it possible.

The different ways water powers the world

10 April 2019

Power generation

If the spectacular Roman aqueducts that still dot the landscape of Europe tell us anything, it’s that hydraulic engineering is nothing new. For thousands of years water power has been used to grind wheat, saw wood, and even tell the time.

Craigside in Northumberland

By the 19th century, water was able to go beyond performing rudimentary mechanical tasks and generate electricity directly. Cragside in Northumberland, England  became the first house powered entirely by hydroelectricity in 1878. By 1881, the whole town of Niagara Falls on the US-Canada border was being powered by the force of its eponymous river and waterfall.

Hydropower has many advantages: it’s predictable, consistent, often zero or low carbon and it can provide a range of ancillary services to power transmission systems. In Great Britain, there is 1.7 gigawatts (GW) of installed hydropower and another 2.8 GW of pumped hydro storage capacity, but it remains a small part of the overall electricity mix. In the fourth quarter of 2018, the 65% of British hydropower that is connected to the national grid accounted for less than one per cent electricity generation or 545,600 megawatt hours (MWh). By contrast, wind accounted for 14% of total generation that quarter (almost 9.5 million MWh).

While hydropower projects can be expensive to construct, operational and maintenance costs are relatively low and they can run for an extremely long time – the Lanark Hydro Electric Scheme in Scotland, which Drax recently acquired, has been producing power since 1927.

Today, hydropower installations are found at all scales, all around the world. But the term hydropower covers many different types of facility. These are some of the ways water is used to generate electricity.

Impoundment power plants

The simplest and most recognisable form of hydropower, impoundment facilities, work by creating a reservoir of trapped water behind a dam that is then selectively released, the water flows through a turbine, spinning it, which in turn activates a generator to produce electricity.

From the Hoover Dam on the Nevada-Arizona border, to the Three Gorges Dam in China – the world’s largest power station of any type, with a generating capacity of 22.5 GW – impoundment dams are some of the most iconic structures in modern engineering.

Three Gorges Dam, China

As well as having the potential to provide large quantities of baseload power, they can react extremely quickly to grid demands – just by opening or closing their floodgates as the power system operator requires.

Run-of-river generation

Rather than storing and releasing power from behind a dam, run-of-the-river generators channel off part of a river and use its natural flow to generate power.

Tongland Power Station, Galloway Hydro Scheme

Because it doesn’t require large dams or reservoirs, run-of-river can be less environmentally disruptive, as there is not always a need for large scale construction and flooding is less common.

Stonebyres Power Station, Lanark Hydro Scheme

While run-of-river facilities tend to be smaller and less flexible than impoundment, they still have significant generating potential – the Jirau hydro-electric power plant on the Madeira river in Brazil has a generating capacity of 3.7 GW.

Pumped storage 

Water can also be good for storing energy that can then be converted to electricity. Pumped hydro storage facilities operate by pumping water uphill to a reservoir when electricity is cheap or plentiful, then letting it flow back downhill through tunnels to a series of turbines that activate generators to generate electricity (in the same way as an impoundment dam) when electricity is in high demand.

Dam and reservoir, Cruachan Power Station

Their ability to both produce and absorb electricity makes them a vital part of electricity networks, playing the role of energy storage systems. In fact, a massive 97% of all global grid storage capacity is in the form of pumped hydro. Their function as giant batteries will only become more important as intermittent renewable sources like wind and solar become more prevalent in the energy mix.

Outlet and loch, Cruachan Power Station.

So too will their ability to ramp up generation very quickly. Drax’s recently acquired Cruachan Power Station in Scotland can go from zero to 100 MW or more in less than 30 seconds when generation is called upon – for example, when there is a sudden spike in demand.   

Tidal range generation

Swansea Bay

The sea is also an enormous source of potential hydropower. Tidal range generation facilities exploit the movement of water levels between and high and low tide to generate electricity. Tidal dams trap water in bays or estuaries at high tide, creating lagoons. The dam then releases the water as the rest of the tide lowers, allowing it to pass through turbines, generating power.

There are limitations – like wind and solar’s dependence on the wind blowing and the level of sunlight, operators can’t control when tides go in or out. But its vast generating potential means that it could be a valuable source of baseload power if it were to be deployed more widely.

Great Britain in particular has major opportunities for tidal generation. The Severn Estuary between England and Wales has the second highest tidal range in the world (15 metres), and a barrage built across the estuary could have a generating capacity of up to 8.6 GW – enough to meet 6% of the Britain’s total electricity demands. Some environmental groups worry about the impact such projects could have on wildlife.

Due to the level of public funding required, the government rejected that plan in 2010, in favour of pursuing its nuclear policy. A second attempt at securing a government-backed investment contract, known as a CfD, for a smaller 320 MW ‘pathfinder’ project in Swansea Bay was also rejected, in 2018. The Welsh government is however supportive of the project, which already has planning permission.

Tidal stream generation

Rather than building a dam, tidal stream generators work like underwater wind turbines. Sturdy propellers or hydrofoils (wing-like blades which oscillate up and down rather than spinning around) are positioned underwater to transform the energy of tidal streams into electricity.

While tidal streams move far slower than wind, the high density of water compared to air means that more power is generated, even at much lower velocities.

Not reliant on large physical structures, tidal stream generators are a relatively cheap form of hydropower to deploy, and make a much smaller impact on their environment than tidal barrages.

Wave generation

Unlike tidal power, which is generated by the gravitational effects of the sun and moon on the Earth’s oceans, wave power ultimately comes from the winds that whip up the ocean’s surface.

There are a number of different methods that turn waves into generation, including funnelling waves into a tube floating on the surface of the water that contains electricity-generating turbines, or by using the vertical bobbing movement of a tethered buoy to pull and spin a fixed generator.

Wave power has yet to be widely implemented, but it has significant potential. It’s estimated that the waves off the coasts of the USA could have provided 66% of the country’s electricity generation needs in 2017 alone. Effectively commercialising wave power could provide another vital tool in developing a sustainable energy landscape for the coming future.

Tidal and wave power generation are less established generation technologies than their land-based cousins but they hold huge potential in delivering more sources of reliable, zero emissions electricity for energy systems in coastal locations around the world.

What causes power cuts?

16 January 2019

Power generation

On the night of 5 December 2015, 61,000 homes and properties across Lancaster were plunged into darkness. Storm Desmond had unleashed torrents of rain on Great Britain, causing rivers to swell and spill over. With waters rising to unprecedented levels, the River Lune began threatening to flood Lancaster’s main electricity substation, the facility where transformers ‘step down’ electricity’s voltage  from the transmission system so it can be distributed safely around the local area.

To prevent unrepairable damage, the decision was taken to switch the substation off, cutting all power across the region. Lights, phones, internet connections and ATMs all went dead across the city. It would take three days of intensive work before power was restored.

It was a bigger power outage than most, but it offers a unique glimpse into the mechanisms behind a blackout – not only how they’re dealt with, but how they’re caused.

What causes blackouts in Great Britain?  

When the lights go out, a common thought is that the country has ‘run out’ of electricity. However, a lack of electricity generation is almost never the cause of outages. Only during the miners’ strikes of 1972 were major power cuts the result of lack of electricity production.

Rather than meeting electricity demand, power cuts in Great Britain are more often the result of disruption to the transmission system, caused by unpredictable weather. If trees or piles of snow bring down one power line, the load of electric current shifts to other lines. If this sudden jump in load is too much for the other lines they automatically trip offline to prevent damage to the equipment. This in turn shifts the load on to other lines which also then trip, potentially causing cascading outages across the network.

Last March’s ‘Beast from the East’, which brought six days of near sub-zero temperatures, deep snow and high winds to Great Britain, is an example of extreme weather cutting electricity to as many as 18,000 people.

High-winds brought trees and branches down onto powerlines, while ice and snow impacted the millions of components that make up the electricity system. Engineering teams had to fight the elements and make the repairs needed to get electricity flowing again.

Lancaster was different, however. With the slow creep of rising rainwater approaching the substation, the threat of long lasting damage was plain to see in advance, and so rather than waiting for it to auto-trip, authorities chose to manually shut it down.

Getting reconnected

Electricity North West is Lancaster’s network operator and after shutting down the substation, it began the intensive job of trying to restore power. On Monday 7 December, two days after the storm hit, the first step of pumping the flooded substation empty of water had finally been completed and the task of reconnecting it began.

To begin restoring power to the region 75 large mobile generators were brought from as far away as the West Country and Northern Ireland and hooked up to the substation, allowing 22,000 customers to be reconnected.

Once partial power was restored, the next challenge lay in repairing and reconnecting the substation to the transmission network. While shutting the facility had prevented catastrophic damage, some of the crucial pieces had to be completely replaced or rebuilt. After three days of intensive engineering work the remaining 40,000 properties that had lost power were reconnected.

Preventing blackouts in a changing system

The cause and scale of Lancaster’s outage were unusual for Great Britain’s electricity system but it does highlight how quickly a power cut may arise. In a time of transition, when the grid is decarbonising and the network is facing more extreme weather conditions because of climate change, it could create even more, new challenges.

Coal is scheduled to be taken entirely off the system after 2025, making the country more reliant on weather-dependent sources, such as wind and solar – potentially increasing the volatility of the system.

On the other hand, growing decentralised electricity generation may reduce the number of individual buildings affected by outages in the future. Solar generation and storage systems present on domestic and commercial property may also reduce dependency on local transmission systems and the impact of disruptions to it.

The cables and poles that connect the transmission system will always be vulnerable to faults and disruptions. However, by preparing for the future grid Great Britain can reduce the impact of storms on the electricity system.

If you’re experiencing a power cut in your area, please call the toll-free number 105 (in England, Scotland and Wales) to reach your local network operator.

How turbines came to power the world

5 September 2018

Power generation

Charles Algernon Parsons knew he was onto something in 1884. The young engineer had joined a ship engineering firm and developed a steam turbine engine, which he immediately saw had a bigger potential than powering boats.

He connected it to a dynamo, turning it into a generator capable of producing up to 7.5 kilowatts (kW) of power, and in the process kickstarted an electrical and mechanical revolution that would reshape how electricity was produced and how the world worked.

Today turbine-based generation is the dominant method for electricity production throughout the world and even now – almost a century and a half later – Parsons’ turbine concept remains largely unchanged, even if the world around it has.

Steam dreams

Throughout the 20th and into the current century, electricity generation has depended on steam power. Be it in a coal, nuclear or biomass power plant, heating water into highly pressurised steam is at the core of production.

Greek mathematician and inventor Hero of Alexandria is cited as building the first ever steam engine of sorts with his aeolipile, which used steam to spin a hollow metal sphere. But it wasn’t until the 18th century, when English ironmonger Thomas Newcomen designed an – albeit inefficient – engine to pump water out of flooded mines, that steam became a credible power in industry.

Scottish engineer James Watt, from whose name the unit of energy comes from, built on these humble beginnings and turned steam into the power behind the industrial revolution around 1764 when he added an condensing chamber to Newcomen’s original design.

It was the combination of this engine with Thomas Edison’s electrical generator late in the 19th century that first made large-scale electricity production from steam a reality.

The turbine takes over

Steam engines and steam power was not a new concept when Parson began his explorations in the space. In fact, nor were steam turbines. Others had explored ways to use stream’s velocity to spin blades rather than using its pressure to pump pistons, in turn allowing rotors to spin at much greater speeds while requiring less raw fuel.

What made Parsons’ design so important was its ability to keep rotational speeds moderate while also extracting as much kinetic energy from steam jets as possible.

He explained in a 1911 Rede Lecture that this was done by “splitting up the fall in pressure of the steam into small fractional expansions over a large number of turbines in series,” which ensured there was no one place the velocity of the blades was too great.

The design’s strength was also apparent at scale. In 1900 his company (which was eventually acquired by Siemens) was building turbine-generator units capable of producing 1,000 kW of electricity. By 1912, however, the company was installing a 25,000 kW unit for the City of Chicago. Parsons would live to see units reach 50,000 kW and become the primary source of electricity generation around the world.

Turbines in the modern grid

The world is a vastly different place to the one in which Parson designed his turbine, yet the fundamentals of his concept have changed very little. The results of what they achieve and the scales at which they work, however, have increased significantly.

Today the turbines that make up Drax’s six generating units are each capable of producing more than 600 MW (or 6,000,000 kW) of electricity with the shape, materials and arrangement of blades carefully designed to maximise efficiency.

And while that first design was purely with steam in mind, turbine technology has advanced beyond dependency on a single power source, and has been developed to accommodate for the shift towards lower-carbon power sources.

One such example is gas turbines, which work by sucking in air through a compressor, which is then heated by burning natural gas, in turn spinning a turbine as it expands. These can jump into action much faster than other turbines as they don’t require any steam to be created to power them.

Renewable sources, such as hydro and wind power, also depend on spinning turbines to generate electricity. Where these differ from gas or steam-powered turbines is that rather than being encased in metal and blasted with gases, wind and hydro turbines’ blades are exposed, so flowing air or water can spin them, powering a generator in turn.

Turbine technology helped bring access to electricity around the world, but the ingenuity and flexibility of the design means it is now serving to adapt electricity production for the post-coal age.