Tag: technology

How electricity is made

25 January 2018

Power generation

Every morning we take electricity as a given. We switch on lights, charge phones and boil kettles without thinking about where this power comes from.

The electronic devices and appliances that make up our daily routines are not particularly energy intensive. Boiling a kettle only uses 93 watts, toasting for three minutes only requires 60 watts, while cooking in a microwave for five minutes takes 100 watts.

However, when people are waking up and making breakfast in almost 30 million households around the UK, those small amounts soon create a significant demand for electricity. On a typical winter’s morning, this combined demand spikes to more than 45 gigawatts (GW).

So this is what it takes to power your breakfast – from the everyday toaster in your kitchen backwards through thousands of miles of cables to the hundreds of thousands of tonnes of machinery in wind farms, hydro-electric dams and at power stations such as Drax where electricity generation begins.

The grid 

The journey starts in the home where all our electricity usage is tracked by meters. These are becoming increasingly ‘smart’, displaying near real-time information on energy consumption in financial terms and allowing more accurate billing. There are already 7.7 million smart meters installed around the UK, but that number is set to triple this year, paving the way for a smarter grid overall.

What brings electricity into homes is perhaps the most visible part of the energy system on the UK’s landscape. The transmission system is made up of almost 4,500 miles of overhead electricity lines, nearly 90,000 pylons and 342 substations, all bringing electricity from power stations into our homes.

Making sure all this happens safely and as efficiently as possible falls to the UK’s nine regional electricity networks and National Grid. Regional networks ensure all the equipment is in place and properly maintained to bring electricity safely across the country, while National Grid is tasked with making sure demand for electricity is met and that the entire grid remains balanced.

The station cools down

One of the most distinctive symbols of power generation, cooling towers carry out an important task on a massive scale.

Water plays a crucial role in electricity generation, but before it can be safely returned to the environment it must be cooled. Water enters cooling towers at around 40 degrees Celsius, and is cooled by air naturally pulled into the structure by its unique shape.

This means those plumes exiting from the top of the towers are, rather than any form of pollution, only water vapour. And this accounts for just 2% of the water pumped into the towers.

Drax counts 12 cooling towers, each 114 metres tall – enough to hold the Statue of Liberty with room to spare. Once the water is cooled it is safe to re-enter the nearby River Ouse.

The station’s bird’s-eye view

The control room is the nerve centre of Drax Power Station. From here technicians have a view into every stage of the power generation process.  The entire system controls roughly 100,000 signals from across the power station’s six generating units, water cooling, air compressors and more.

While once this area was made up of analogue dials and controls, it has recently been updated and modernised to include digital interfaces, display screens and workstations specially designed by Drax to enable operators to monitor and adjust activity around the plant.

The heart of power generation 

At the epicentre of electricity generation is Drax’s six turbines. These heavy-duty pieces of equipment do the major work involved in generating electricity.

High-pressure steam drive the blades which rotates the turbine at 3,000 revolutions per minute (rpm). This in turn spins the generator where energy is converted into the electricity that will eventually make it into our homes.

These are rugged pieces of kit operating in extreme conditions of 165 bar of pressure and temperatures of 565 degrees Celsius. Each of the six turbine shaft lines weighs 300 tonnes and is capable of exporting over 600 megawatts (MW) into the grid.

One of the most important parts of the entire process, turbines are carefully maintained to ensure maximum efficiency. Even a slight percentage increase in performance can translate into millions of pounds in savings.

Turning fuel to fire

To create the steam needed to spin turbines at 3,000 rpm, Drax needs to heat up vast amounts of water quickly and this takes a lot of heat.

The power station’s furnaces swirl with clouds of the burning fuel to heat the boiler. Biomass is injected into the furnace in the form of a finely ground powder. This gives the solid fuel the properties of a gas, enabling it to ignite quickly. Additional air is pumped into the boiler to drive further combustion and optimise the fuel’s performance.

Pulveriser

How do you turn hundreds of tonnes of biomass pellets into a powder every day? That’s the task the pulveriser take on. In each of the power plant’s 60 mills, 10 steel and nickel balls, each weighing 1.2 tonnes, operate in extreme conditions to crush, crunch and pulverise fuel.

These metal balls rotate 37 times a minute at roughly 3 mph, exerting 80 tonnes of pressure, crushing all fuel in their path. Air is then blasted in at 190 degrees Celsius to dry the crushed fuel and blow it into the boiler at a rate of 40 tonnes per hour.

The journey begins: biomass arrives

Biomass arrives at Drax by the train-load. Roughly 14 arrive every day at the power station, delivering up to 20,000 tonnes ready to be used as fuel.

These trains arrive from ports in Liverpool, Tyne, Immingham and Hull and are specially designed to maximise the efficiency of the entire delivery process, allowing a full train to unload in 40 minutes without stopping.

The biomass is then taken to be stored inside Drax’s four huge storage domes. Each capable of fitting the Albert Hall inside, the domes can hold 300,000 tonnes of compressed wood pellets between them.

Here the biomass waits until it’s needed, at which point it makes its way along a conveyor belt to the pulveriser and the process of generating the electricity that powers your breakfast begins.

Can electricity power heavy-duty vehicles?

3 January 2018

Electrification

On a blacked-out stage, a blast of white light appears. Smoke floods out, music blares and an excited crowd surges forward, smartphones held aloft. It’s a moment of rapture – but this is not a theatrical or musical performance. This is the launch of an electric car.

Specifically, the launch of Tesla’s new electric roadster – which claims to be the fastest production car ever made. And while the sportscar may have been the undoubted star of the event, it wasn’t the only one unveiled. Tesla also launched an electric-powered articulated lorry – the Semi.

With governments around the world setting ambitious plans to ban the sale of petrol-and-diesel-only cars, the introduction of electric-powered utility vehicles – like Tesla’s truck – in a range of industries will be essential to a truly decarbonised transport system.

Disrupting trucking

Tesla’s heavy goods vehicle (HGV) highlights the growing capabilities of electric vehicles (EVs) to deliver more than just short, urban journeys. It claims its Semi will be able to travel 500 miles on a single charge (enough to get you from London to Edinburgh comfortably) and tow 40 tonnes of cargo.

Tesla isn’t the only player with electric big rig concepts – Los Angeles-based Thor Trucks, Daimler and Volkswagen have unveiled their own – but its ambitious 2019 production target makes it a more immediate possibility than any other in the space.

Despite media coverage claiming the Semi’s mega-charging capability breaks the laws of physics, big business is taking a sunny view of Elon Musk’s latest innovation. Walmart, which has been taking strides to reduce its emissions, has already pre-ordered 15 of the Semis. Delivery firm UPS has used small electric trucks in major cities for some years already – it has placed the largest order so far, for 125.

Electrifying emergency response

In the world of emergency services, quick response is vital. EVs, then, which have fast acceleration and are quick off the mark, are ideal candidates to deliver – especially as battery technology becomes more reliable and durable.

Health services in Nottingham have already been trialling electric-powered fast response vehicles, while in Japan, Nissan has unveiled an all-electric ambulance that carries a lithium-ion auxiliary battery to power medical equipment on board.

This on-board power supply is a further advantage of EVs, and one not just restricted to emergency services. Electric pickup truck maker Havelaar, for example, offers power outlets on its Bison vehicle for electric tools.

The future of battery farming

Out in the countryside, EVs are making waves in farming. John Deere has unveiled plans for fully electric tractors, claiming they require less maintenance and have a longer lifecycle than combustion engines.

With more than a third of UK farms generating their own power from solar, wind and even anaerobic digestion using farm by-products, there’s potential for farmers to charge tractors renewably and cut their fuel and charging costs.

More than just helping cut emissions and costs, there can also be performance benefits. Given their acceleration abilities, electric tractors are well suited to heavy pulling without revving up engines and churning up ground.

Joining HGVs and tractors in their ability to apply almost instant torque to heavy industrial jobs are e-Dumper trucks. The Komatsu quarry truck weighs in at almost 45 tonnes and claims to be the biggest EV in the world.

The economic advantage of electrification

Air pollution and greenhouse gas emissions are the main driving force behind many anti-fossil fuel regulations. However, research suggests decarbonising transport systems also have economic advantages for businesses.

A report by financial services firm Hitachi Capital found that switching vans and heavy goods vehicles (HGVs) to electric or other alternative fuels could save British businesses as much as £14 billion a year.

It claims EVs run at 13p cheaper per mile than diesel-fuelled vans, while HGVs are reported to be 38p cheaper. That adds up to total savings of £13.7 billion a year if all Britain’s commercial vehicles were switched.

The move to a fully electrified transport system is already underway. The number of registered electric cars increased by 280% in the UK over the past four years, according to the Hitachi report. The Chinese city of Shenzhen’s entire fleet of 16,359 buses has gone electric – a transition that began in 2009 and has been assisted by an 80% drop in the cost of a lithium-ion battery pack. According to Bloomberg New Energy Finance, China’s need for electric bus batteries is almost on a par to that of all global EV battery demand. China could be said to be driving the market.

EVs are undoubtedly cleaner when it comes to road-side pollution. However, the exponential increase in EVs will only benefit the fight against man made climate change if countries’ entire energy systems continue to decarbonise. Emissions-free vehicles will need to be powered predominantly by low carbon electricity for a more electric future to be a sustainable one.

Refurbishing a 300-tonne generator core within the heart of a power station

6 December 2017

Power generation
Electricity generator

At the centre of Drax Power Station, in a corner of the cavernous turbine hall, is a white box. The inside of this box is spotlessly clean. Not only are its white walls free of dirt, they are free of even dust. But there is one outlier inside this sterile environment: a 300-tonne chunk of industrial equipment.

This equipment is a generator core – the central component for converting the mechanical energy to electrical power.

Electricity generator core

The core is driven by the steam turbine. Ninety tonnes of generator rotor spinning at 3,000 rpm with just millimetres of clearance from the core produce 660 megawatts (MW) of electricity. That’s enough – 645 MW when exported from Drax into the National Grid – to power a city the size of Sheffield.

The generator is a serious piece of industrial machinery. And despite the pristine conditions, this white box is the site of serious engineering.

A process normally done by large-scale manufacturers in dedicated factories, ‘rewinding’ a generator core – as the process is called – is a major operation.

No other UK facility is capable of doing this complex job. So it’s here, in a white box, in the middle of an operational power station in North Yorkshire, that a team of engineers is undertaking work that will secure the generator’s use for decades. This is the Drax rewinding facility.

Turbine structure

How a generator works

A generator consists of two main components, a spinning rotor and a stationary stator. The rotor, which is directly connected to the main turbine and spins 50 times every second, sits inside the stator. Both the stator and the rotor contain a large number of copper coils known as windings. These windings are what carry the electrical current.

The rotor acts like a very strong electromagnet, which, when a voltage is applied, produces a strong magnetic field. Because the rotor sits inside the stator, this magnetic field intersects the copper windings of the stator and induces a voltage in these windings, allowing current to flow.  This voltage is then brought out of the stator and passed through a step-up transformer, where it is increased to a level suitable for transmission through the National Grid.

The stator core is made from many elements with hundreds of thousands of laminations, 84 water-cooled insulated copper bars, each 11 metres long and weighing 200kg forming the windings, various insulating materials, blocks, packing, wedges and condition monitoring equipment.

Generator stators can operate for decades without fault.

DIY at Drax

In 2016, a team of engineers at Drax embarked on a project to construct a facility to rewind the stator on site. This required cross-company collaborative working to design and construct this huge purpose built facility.

Contamination can cause operational problems, so the team built a sterile, white room within the turbine hall – one of just two places within the power station with foundations strong enough to support the incredible 450 tonnes required for the rewind facility. Designed to hold the stator core and the conductor bars, air is forced out of the room to limit the possibility of contamination to the core during the rewind.

“When the unit is in service it becomes magnetic, so any metallic particles left in the space will be attracted to the core,” explains Drax electrical engineer Thomas Walker. “Once magnetised, any metal particles could be drawn in, burrowing into the insulation and core lamination.”

This is the kind of event that an electricity generator wants to avoid – but when it happens, be prepared to fix it.

Roll with it

When Drax’s stators were manufactured in the 1980s, completing their construction relied on manual handling techniques. Modern day facilities, however, rotate the core to minimise human contact.

It took just six months for a partnership involving Drax, Siemens and ENSER to manufacture what could be the largest stator rollers in the world and within that time, ship them from the US to North Yorkshire.

With the rollers installed, the next step was to move in the core. Two of the turbine hall’s cranes, each capable of lifting 150 tonnes, were combined to lift it, hoisting the core onto the mechanical ‘roller’ within the rewind facility.

Once in place, the roller rotates the core, allowing for the copper conductor bars to be safely removed and inserted. Despite this mechanical help, the removing and replacing of each one is still at its heart a human job.

“We still need 10 men to physically move the conductor bars with lifting aids, which makes it not an easy process,” says Walker. Using this method, the bars weighing 200kg each can be safely and precisely fitted into the core.

Electricity turbine generator at Drax

Opting for in-house

Rewinding a stator is a complex process. However, when the time, logistics and costs of shipping the core to Siemens – the German-based manufacturers – was factored in, the decision to do the work at Drax Power Station was an easy one.

“A 300-tonne core is not easy to transport and the Highways Agency do not like things like that on the roads. They’d want us to use waterways” says Drax lead engineer Mark Rowbottom. “Logistically it just wasn’t worth it. It’s too much money to move and ship that weight to Germany. So, we looked at what we could do onsite.”

More than just an economical and logistical decision and with the UK’s diminishing manufacturing facilities, Drax is now equipped to support generator rewinds for many years to come. Building and operating the rewind facility was a project that leveraged the engineering abilities of Drax employees. They are increasingly doing engineering traditionally outsourced to equipment manufacturers.

“The experience we have gained and the close working relationship we have established with Siemens enables us to support the generator for the remaining life of the station,” says Rowbottom.

“To see the core in that many pieces and stripped down to this level is very rare,” says Walker, who began working at the plant as an apprentice. Of the 84 conductor bars, half have been fitted, and the team is scheduled to complete the stator rewind in early 2018. “I never thought I’d do anything like this but am proud to say that I’ve done it.”

The UK’s secret economic juggernaut: the North

29 September 2017

Sustainable business

The North of England is home to some 15 million people. This makes up almost a quarter of the UK’s total population, and includes a mesh of proud local identities.

Compared to the rest of the UK, however, there is a persistent gap in GVA (gross value added) per capita and productivity performance. Analysis by the Treasury claimed that if the North’s economy grew as quickly as the UK average to 2030, its economic output would be £37 billion higher in real terms. There’s huge potential in North, but it needs the right support to unlock it.

The Northern Powerhouse Partnership is a business-led organisation aiming to do just that. In a new report, Powerhouse 2050: Transforming the North, it explores four areas of the economy, originally identified in the Northern Powerhouse Independent Economic Review, where the North has the potential to be a world leader within the next 33 years.

Given the right cooperation between business, university and government investment, these four sectors could create 850,000 more jobs and contribute an extra £100 billion to the UK economy by 2050.

New extra large press starts production at Nissan Sunderland, via Nissan Europe Newsroom

Advanced manufacturing and materials

The North has a strong history in manufacturing, from traditional steel production in Sheffield to shipbuilding in Hull. The region is currently home to several car manufacturing plants, including Vauxhall, Jaguar Land Rover and Nissan.

Building on this pedigree, the North’s real strengths lie in its ability to improve processes and productivity, as well as the development of new products.

Two key areas where it could be a world leader heading into 2050, are new lightweight and 2D materials, as well as high-precision engineering. Close connections between research institutions and manufacturing industries will help provide businesses in the region with access to cutting edge technology and the highly-skilled workforce needed to operate it. 

Siemens and Drax engineers worked together to upgrade turbines at Drax Power Station. The five-year, £100m project was completed in 2012 [find out more]

Energy

The North has a long history of powering the UK and today still generates 41% of England’s electricity. Building on this strength in the field, the region has the potential to evolve into a world leader in the modern, low-carbon energy sector, through the repurposing of existing infrastructure, such as Drax Power Station’s transition from coal to biomass fuel.

“The North is uniquely placed to deliver the UK’s energy needs,” said Drax Power CEO Andy Koss. “There are huge opportunities for us as a region – not just in terms of potential jobs and the economic benefits, but also the positive environmental impacts associated with decarbonisation.”

Electricity generation, storage and low carbon technologies including nuclear, offshore wind and bioenergy are already well established in the North. However, there are also opportunities to re-use existing infrastructure, such as ‘greening’ the gas grid in Leeds by converting it to low carbon hydrogen. 

Digital

The digital and tech sectors are often seen as a major driver for well-paid jobs that can drive national productivity and the wider economy. And while London remains the central hub for venture capital funding and high-profile startups, a report by Tech Nation found almost 70% of total investment in tech went to companies outside the capital in 2016.

This includes £78 million raised by Manchester tech businesses and £61 million invested in Sheffield companies. In fact, the wider digital sector, from adtech to fintech, now employs 168,671 people across city clusters in the North.

This is a strong base from which to grow the region’s tech and digital scene, which will be supported by initiatives such as the £400 million Northern Powerhouse Investment Fund and the £30 million for the region’s new National Innovation Centre for Data. 

Health innovation

The North has long-established strengths in fields such as life sciences, medical technologies and devices. These include pharmaceutical and medical device manufacturing hubs across the region.

What makes the UK unique in the health innovation space is its ability to leverage the National Health Service as an asset for research, innovation and in developing new models of healthcare delivery – and the North is no different. This collaboration can allow companies and institutions in the field to sit at the forefront of implementing and developing treatments, medicines and devices for the 21st century.

The future of health innovation will be closely connected to tech fields of big data and AI and these, along with other types of research will require close collaboration between businesses, the NHS and the regions’ universities.

Within the relatively small UK, the North may still be a small part, often eclipsed by the country’s capital. But as the report shows, there is not only huge potential yet to be realised, but a strong history on which to build.

How artificial intelligence will change energy

20 September 2017

Electrification

At the beginning of 2016, the world’s most sophisticated artificial intelligence (AI) beat World Champion Lee Sedol at a game called ‘Go’ – a chess-like board game with more move combinations than there are atoms in the universe. Before this defeat, Go had been considered too complicated for even the most complex computers to beat the top humans.

It was a landmark moment in the development of ever-more sophisticated AI technology. But the future of AI holds more than simply board game victories. It is rapidly finding its way into all aspects of modern life, prompting the promise of a ‘Fourth Industrial Revolution’.

One of the areas AI has huge potential is in our energy system. And this could have implications for generators, consumers and the environment.

Artificial intelligence playing traditional board game Go concept

The National Grid gets wise

Earlier this year the UK’s National Grid revealed it’s making headway in integrating AI technology into Britain’s electricity system. It announced a deal with Google-owned AI company (and creator of the Go Champion-beating system) DeepMind which is set to improve the power network’s transmission efficiency by as much as 10%.

One of the National Grid’s most important tasks is maintaining the frequency of Britain’s power networks to within ±1% of 50Hz. Too high a frequency and electrical equipment gets damaged; too low a frequency and you get blackouts. Managing this relies on ensuring electricity supply and demand are carefully balanced. But this is made increasingly difficult with the growing number of intermittent renewables – such as wind and solar – on the grid.

The ability to process massive amounts of information from a wide variety of data points (from weather forecasts to internet searches to TV listings) and create predictive models means AI can pre-empt surges in demand or instances of oversupply. In short, it can predict when the country will need more power and when it will need less.

More than this, it can respond to these fluctuations in sustainable and low-carbon ways. For example, it can automate demand side response, where energy users scale back their usage at peak times for a reward. Similarly, it can automate the purchasing of power from battery systems storing renewable energy, such as those connected to domestic solar arrays.

These solutions, which would see AI help to manage supply and demand imbalances, would ease some grid management pressures, while large thermal generators controlled by human engineers back up such automation with their continuing focus on maintaining grid stability through ancillary services.

The role of the smart city

An undoubtedly large factor in the growing sophistication of AI in the energy space is the amount of energy use data now being captured. And this has much to do with the increasing prevalence of smart devices and connected technology.

Smart meters – which will be offered to every UK home by 2020 – such as Alphabet’s Nest smart thermostat, and start-up Verdigris’s energy conserving Internet of Things (IoT) devices are just a few of the emerging technologies using data to improve individuals’ abilities to monitor and optimise their household energy use.

But at scale, information collected from these devices can be used by AI to help control energy distribution and efficiency across entire cities – and not just at a macro level, but right down to individual devices.

The idea of a central computer controlling home utilities may seem like a soft invasion of privacy to some, but when it comes to the energy-intensive function of charging electric vehicles (EVs), much of this optimisation will be carried out in public on street charge points.

As AI and smart technology continue to grow more sophisticated, it has the potential to do more than just improve efficiency. Instead, it could fundamentally change consumers’ relationships with energy.

Changing consumer relationships with energy

Start-ups in the energy space, such as Seattle-based Drift, are exploring how trends such as peer-to-peer services and automated trading can be enabled through machine AI and give consumers greater control over their energy for a lower price.

The company offers consumers access to its own network of distributed and renewable energy sources. Currently operating in New York, it uses AI to assess upcoming energy needs based on data collected from individual customers and location-specific weather forecasts. It then uses this to buy power from its network of peer-to-peer energy providers, using high-frequency, algorithmic trading to reduce or eliminate price spikes if demand exceeds expectation.

Yet to be operational in the UK, this sort of automation and peer-to-peer energy supply hints at the increasing decentralisation of energy grids, which are moving away from relying only on a number of large generators. Instead, modern grids are likely to rely on a mix of technologies, generators and suppliers. And this means a more complex system, which is precisely why automation from a central AI system could be a positive step.

Not only could it bring about optimisation and efficiency, but it could slash emissions and costs for consumers. This silent automation may not have the same headline-grabbing qualities as beating a world champion in their chosen sport, but its impact to the country could be far greater.

Inertia: the shock absorbers keeping the grid stable

12 September 2017

Power generation

From the comfort of home, it’s easy to assume Britain’s power is run across a consistently calm and stable system. And while this is for the most part true, keeping it this way relies on a set of carefully calibrated and connected tools.

These include frequency response – which keeps all electricity around the country on the same frequency – and reactive power – the quiet force moving electricity around the grid. But there’s another at play, and at least by name, it’s something you’ve probably heard of: inertia.

System inertia is energy stored in spinning plant that slows down the rate at which frequency changes. Rapid changes in frequency can create instability in the system. Think of it like a car – inertia does the same job as shock absorbers in the suspension, smoothing the sudden bumps and potholes, keeping the wheels on the ground to maintain control.

However, the changing nature of Britain’s energy system is creating challenges in ensuring there is enough inertia available for a stable future grid.

The energy system’s shock absorbers

Inertia describes objects’ natural tendency (whether they’re moving or resting) to keep doing what they’re doing until forced to change. For example, when you kick a pebble, forces like friction and gravity prevent it hurtling endlessly off into the distance.

Electricity generation in thermal power stations such as Drax involves many moving parts, none more important than turbines and generators. In a turbine, high pressure steam hits a set of blades which makes it spin. A little like running a fan in reverse. The spinning motion is used to power the generator which is a rotor wound in electrified copper wire, transforming it into an electro magnet. As this magnetic field passes through copper bars surrounding the rotor it generates electricity.

This spinning turbine has inertia. If the fuel powering it is suddenly switched off it will continue to spin until it is stopped either by friction or by force. Every thermal generator in the UK system spins at 3,000 rpm, has inertia, and generates electricity at a frequency of 50 Hz. In the UK, all electricity is generated at the same frequency and crucially needs to remain stable – even deviations of 1% from this can damage equipment and cause blackouts.

Managing frequency is done by managing generation. If demand exceeds supply, frequency falls; too much supply and frequency rises. National Grid closely monitors frequency across the system and automatically instructs power generators like Drax to respond to changes in frequency by dialing up or down generation.

And ensuring this change in generation is done smoothly and instantaneously relies on using inertia. For example, using the inertial forces of spinning generators, power stations are able to respond instantly to requests to alter generation.

So, inertia is important to the stability of the power system. But because of the changing nature of today’s grid, we are facing challenges when it comes to inertia. Many forms of renewable generation aren’t built around spinning turbines. And this means no inertia.

Future Challenges

Renewable sources like the wind turbines currently operational in the UK and solar PV, alongside energy imported from the continent, do not provide inertia to the grid.

This means as the UK moves to decarbonise the energy system and rely on more intermittent and often embedded renewable energy rather than thermal-generated electricity, questions arise over where the grid will get the inertia needed to remain stable.

One possible solution is synthetic inertia. While wind turbines do not contain inherit inertia, modern suppliers are now enabling the machine’s rotating blades to create synthetic inertia, which can add extra power to the grid to support generation loss. Some regions, including Germany and Quebec, now require inertia-generation in turbines as standard.

This can’t be done with solar PV. However, smart grids and improving storage technologies have the potential to deal with a lack of inertia. Batteries, which can absorb electricity when there is an oversupply and then release it again when demand is high, can respond near-instantly to fluctuations to help maintain the grid’s frequency.

There are, of course, renewable sources that offer natural inertia, including hydro, tidal and biomass generation. But as the UK shifts to more renewable energy sources with no naturally occurring inertia, these turbine-based generation methods will be vital in ensuring wider grid stability.  Gas has an important role too, as a lower carbon alternative to coal power and one that will increasingly shift from being the backbone of Britain’s electricity system to playing a supporting, flexible role.

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

The technologies transforming the next decade of energy supply

5 September 2017

Power generation

In the last decade Britain’s energy system has seen a fundamental shift towards cleaner and renewable energy. And while proactive governmental policy has played a large role, much of what has made this shift possible is technological improvement.

Innovations in energy technology will play an equally major role in ensuring the same level of progression over the next 10 years. A report by National Grid has identified some of the most promising of these emerging tech solutions, and outlines which have the highest probability of aiding our continued decarbonisation.

Future scenarios aside, what’s certain from looking at this year’s Electric Insights is that, a decade from now, the power system will look very different. These are the technologies that could change it.

Homes that power themselves

Solar is already an important part of Britain’s renewable power infrastructure, but it has the potential to grow through smaller domestic setups, too. Access to DIY rooftop solar is becoming increasingly prevalent, with even home store giant IKEA allowing customers to pick up a solar panel and battery system alongside flat-pack furniture.

Meanwhile, solar technology continues to improve, helping it become more easily integrated into buildings. Tesla is soon to introduce solar arrays that look almost identical to high-end roofing tiles as well as transparent, solar power-generating windows. Homeowners and business are also looking to onsite biomass boilers to take control of their own green energy.

As such systems reach mainstream consumers they present the potential to create a more decentralised energy system.

Photo courtesy of Kite Power Systems

A new type of wind energy – powered by kites

Wind is already a key source of renewable energy, with on and offshore wind turbines now commonplace in many parts of the UK. But innovation continues, and now companies are looking to higher altitudes to improve the efficiency of wind generation.

In May of this year the UK gave the go ahead to the world’s first kite farm, a wind generation facility that will use two massive kites flying in loops roughly 450 metres above the ground to pull turbines and generate electricity. The company behind the project, Kite Power Systems, claims the system offers a lower Levelised Cost of Energy (LCoE) and operational maintenance cost than conventional wind.

Bigger, more efficient batteries

Many of the technologies set to shape the future of green energy, from domestic solar to electric vehicles (EVs), are dependent on innovations in battery technology.

Solid state batteries, which use a solid electrolyte rather than the semi-liquid type found in standard lithium-ion batteries, offer a number of potential performance benefits. These include six times faster charging, twice the energy density, and a longer life cycle.

The challenge is producing the batteries at a large scale and a competitive price point. Companies including Dyson, Bosch, Tesla and Toyota are all making strides in bringing them to market, with the latter aiming to implement the technology by 2020.

Wind turbines that don’t turn

The wind turbine has become an icon of renewable energy, but this could change – not because of a decrease in wind energy, but in a transformation in how they look.

Innovation in the wind energy space has led to the development of bladeless turbines, which offer the potential to reduce costs and minimise the noise and visual impact associated with traditional turbines.

Rather than rotating blades, bladeless turbines oscillate as wind passes a single, conical mast. Spanish bladeless turbine developer Vortex claims the lack of contact between moving parts can cut 80% of maintenance costs due to there being no need for lubricants and spare parts replacements. The firm hopes to bring industrial-sized turbines to the market by the turn of the decade. 

The next generation of nuclear

The next generation of nuclear reactor technology could offer the potential for more efficient, economic and safer nuclear energy. Current solutions being developed include reactors cooled by lead and gas, and a molten salt reactor, which uses molten fluoride salt to dissolve fuel.

Hopes for these ‘generation IV’ reactors include the ability to work faster and more efficiently, delivering more energy from the same amount of fuels, and the ability to use waste products from older reactors. The first generation IV systems are expected to be ready for commercial construction around 2020 to 2030.

The renewable technologies set to thrive beyond 2030

While the immediate future holds massive potential for a handful of energy technologies, there are others that will take longer to come to fruition. Once realised, however, they could provide significant breakthroughs.

Methane hydrate, found primarily under permafrost and near the ocean floor, is thought to offer greater supplies of methane than all the planet’s natural gas and oil sources combined.  Burnt as a natural gas, methane releases much less CO2 than other hydrocarbons and can greatly reduce transport emission when used as a liquefied natural gas (LNG) in vehicles.

Finding a way to safely extract these methane deposits could provide as much as 1,500 years’ worth of energy at current production rates.

Meanwhile, the greatly reduced release of radioactive material from nuclear fusion over nuclear fission could offer a huge advantage in its development as a future energy technology.

There is, however, no magic bullet that will be the single solution to a cleaner energy future. Instead, like today’s power system, it will rely on a mix of technologies, fuels and generators, working together to ensure a stable – and cleaner – energy system.

4 of the most exciting emerging technologies in electricity generation

6 July 2017

Power generation
Petri dish with microbe colony

Since the dawn of the industrial age, the world has been powered by a relatively small set of technologies. The 20th century was the age of coal, but this side of 2000, that’s changed.

The need to curb emissions and the rise of renewables, from wind to solar to biomass, has significantly changed how we fuel our power generation.

Today, some of the world’s most interesting and exciting emerging technologies are those designed to generate electricity.

Microbial fuel cells – harnessing the power of bacteria

Bacteria are all around us. Some are harmful, some are beneficial, but all of them ‘breathe’. When they breathe oxidation occurs, which is when something combines with oxygen at a chemical level, and when bacteria do this, electrons are released.

By connecting breathing microbes to a cathode and an anode (the positive and negative rods of a battery), the flow of these released electrons can be harnessed to generate power. This is what’s known as a microbial fuel cell (MFC). MFCs are used largely to generate electricity from waste water, but are expanding into more exotic uses, like powering miniature aquatic robots.

New developments are constantly expanding the power and applications of MFCs. Researchers at Binghamton University, New York found that combining phototropic (light-consuming) and heterotrophic (matter-consuming) bacteria in microbial fuel reactions generates currents 70 times more powerful than in conventional setups.

Building with sun shining through glass windows

Solar – a new dawn

Solar power may not be a new technology, but where it’s going is.

One of the most promising developments in the space is solar voltaic glass, which has the properties of a sheet of window glass but can also generate solar power.

Rather than collecting photons like normal solar does (and which transparent materials by definition can’t do) photovoltaic glass uses salts to absorb energy from non-visible wavelengths and deflects these to conventional solar cells embedded at the edge of each panel.

Or there’s solar PV paint, which contains tiny light sensitive particles coated with conductive materials. When layered over electrodes you’ve got a spray-on power generator.

Nuclear reactor hall in a power plant

Betavoltaics – nothing wasted from nuclear waste

Nuclear material is constantly decaying and in the process emits radioactive particles. This is why extremely radioactive material is so dangerous and why properly storing nuclear waste is so important and so expensive. But this waste can actually be put to good use. Betavoltaic devices use the waste particles produced by low-level radioactive materials to capture electrons and generate electricity.

The output from these devices can be fairly low and decreases over long periods of time, but because of the consistent output of nuclear decay they can be extremely long-lasting. For example, one betavoltaic battery could provide one watt of power continuously for 30 years.

And while they aren’t currently fit to work on a large scale, their longevity (and very compact size) make them ideal power sources for devices such as sensors installed on equipment that needs to be operational for long periods.

Ocean wave crashing at shore

Tidal power – changing tides

A more predictable power source than intermittent renewables like wind and solar, tidal power isn’t new, however its growth and development has typically been restrained by high costs and limited availability. That’s changing. Last year saw the launch of the first of 269 1.5 MW (megawatt) underwater turbines, part of world’s first large scale tidal energy farm in Scotland.

Around the world there are existing tidal power stations – such as the Sihwa Lake Tidal Power Station in South Korea, which has a capacity of 254MW – but the MeyGen array in Scotland will be able to take the potential of the technology further. It’s hoped that when fully operational it will generate 398MW, or enough to power 175,000 homes.

We might not know exactly how the electricity of tomorrow will be generated, but it’s likely some or all of these technologies will play a part. What is clear is that our energy is changing.

This is how you unload a wood chip truck

30 June 2017

Sustainable bioenergy
Truck raising and lowering

A truck arrives at an industrial facility deep in the expanding forestland of the south-eastern USA. It passes through a set of gates, over a massive scale, then onto a metal platform.

The driver steps out and pushes a button on a nearby console. Slowly, the platform beneath the truck tilts and rises. As it does, the truck’s cargo empties into a large container behind it. Two minutes later it’s empty.

This is how you unload a wood fuel truck at Drax Biomass’ compressed wood pellet plants in Louisiana and Mississippi.

What is a tipper?

“Some people call them truck dumpers, but it depends on who you talk to,” says Jim Stemple, Senior Director of Procurement at Drax Biomass. “We just call it the tipper.” Regardless of what it’s called, what the tipper does is easy to explain: it lifts trucks and uses the power of gravity to empty them quickly and efficiently.

The sight of a truck being lifted into the air might be a rare one across the Atlantic, however at industrial facilities in the United States it’s more common. “Tippers are used to unload trucks carrying cargo such as corn, grain, and gravel,” Stemple explains. “Basically anything that can be unloaded just by tipping.”

Both of Drax Biomass’ two operational pellet facilities (a third is currently idle while being upgraded) use tippers to unload the daily deliveries of bark – known in the forestry industry as hog fuel, which is used to heat the plants’ wood chip dryers – sawdust and raw wood chips, which are used to make the compressed wood pellets.

close-up of truck raising and lowering

How does it work?

The tipper uses hydraulic pistons to lift the truck platform at one end while the truck itself rests against a reinforced barrier at the other. To ensure safety, each vehicle must be reinforced at the very end (where the load is emptying from) so they can hold the weight of the truck above it as it tips.

Each tipper can lift up to 60 tonnes and can accommodate vehicles over 50 feet long. Once tipped far enough (each platform tips to a roughly 60-degree angle), the renewable fuel begins to unload and a diverter guides it to one of two places depending on what it will be used for.

“One way takes it to the chip and sawdust piles – which then goes through the pelleting process of the hammer mills, the dryer and the pellet mill,” says Stemple. “The other way takes it to the fuel pile, which goes to the furnace.”

The furnace heats the dryer which ensures wood chips have a moisture level between 11.5% and 12% before they go through the pelleting process.

“If everything goes right you can tip four to five trucks an hour,” says Stemple. From full and tipping to empty and exiting takes only a few minutes before the trucks are on the road to pick up another load.

Efficiency benefits

Using the power of gravity to unload a truck might seem a rudimentary approach, but it’s also an efficient one. Firstly, there’s the speed it allows. Multiple trucks can arrive and unload every hour. And because cargo is delivered straight into the system, there’s no time lost between unloading the wood from truck to container to system.

Secondly, for the truck owners, the benefits are they don’t need to carry out costly hydraulic maintenance on their trucks. Instead, it’s just the tipper – one piece of equipment – which is maintained to keep operations on track.

However, there is one thing drivers need to be wary of: what they leave in their driver cabins. Open coffee cups, food containers – anything not firmly secured – all quickly become potential hazards once the tipper comes into play.

“I guess leaving something like that in the cab only happens once,” Stemple says. “The first time a trucker has to clean out a mess from his cab is probably the last time.”