Tag: technology

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.

What’s next for bioenergy?

11 July 2017

Sustainable bioenergy
Morehouse BioEnergy in Louisiana

Discussions about our future are closely entwined with those of our power. Today, when we talk about electricity, we talk about climate change, about new fuels and about the sustainability of new technologies. They’re all inexplicably linked, and all hold uncertainties for the future.

But in preparing for what’s to come, it helps to have an idea of what may be waiting for us. Researchers at universities across the UK, including the University of Manchester and Imperial College London, have put their heads together to think about this question, and together with the Supergen Bioenergy programme they’ve created a unique graphic novel on bioenergy that outlines three potential future scenarios.

Based on their imagined views of the future there’s plenty to be optimistic about, but it could just as easily go south.

Future one: Failure to act on climate change

Dams on river

In the first scenario, our energy use and reliance on non-renewable fuels like oil, coal and gas continues to grow until we miss our window of opportunity to invest in renewable technology and infrastructure while it’s affordable.

Neither the beginning nor the end of the supply chain divert from their current trends – energy providers produce electricity and end users consume it as they always have. Governments continue to pursue growth at all costs and industrial users make no efforts to reverse their own rates of power consumption. In response, electricity generation with fossil fuels ramps up, which leads to several problems.

Attempts to secure a dwindling stock of non-renewable fuels lead to clashes over remaining sources as nations vie for energy security. As resources run out, attempts to put in place renewable alternatives are hampered by a lack of development and investment in the intervening years. The damages caused by climate change accelerate and at the same time, mobility for most people drops as fuel becomes more expensive.

Future two: Growing a stable, centralised bioenergy

Rows of saplings ready for planting

A future of dwindling resources and increasing tension isn’t the only way forward. Bioenergy is likely to play a prominent role in the energy mix of the future. In fact, nearly all scenarios where global temperature rise remains within the two degrees Celsius margin (recommended by the Paris Agreement) rely on widespread bioenergy use with carbon capture and storage (BECCS). But how far could the implementation of bioenergy go?

A second scenario sees governments around the world invest significantly in biomass energy systems which then become major, centralised features in global energy networks. This limits the effects of a warming climate, particularly as CCS technology matures and more carbon can be sequestered safely underground.

This has knock-on effects for the rest of the world. Large tracts of land are turned over to forestry to support the need for biomass, creating new jobs for those involved in managing the working forests. In industry, large-scale CCS systems are installed at sizeable factories and manufacturing plants to limit emissions even further.

Future 3: The right mix bioenergy

Modern house with wind turbine

A third scenario takes a combined approach – one in which technology jumps ahead and consumption is controlled. Instead of relying on a few concentrated hubs of BECCS energy, renewables and bioenergy are woven more intimately around our everyday lives. This relies on the advance of a few key technologies.

Widespread adoption of advanced battery technology sees wind and solar implemented at scale, providing the main source of electricity for cities and other large communities. These communities are also responsible for generating biomass fuel from domestic waste products, which includes wood offcuts from timber that makes up a larger proportion of building materials as wooden buildings grow more common.

Whether future three – or any of the above scenarios – will unfold like this is uncertain. These are just three possible futures from an infinite range of scenarios, but they demonstrate just how wide the range of futures is. It’s up to us all – not just governments but businesses, individuals and academics such as those behind this research project too – to to make the best choices to ensure the future we want.

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.”

What does the internet of things mean for energy?

2 June 2017

Electrification

Internet of things (IoT) technology, which connects everyday appliances to one another allowing them to collect data and become ‘smart’, presents an exciting view of the modern home or workspace.

The future IoT-enabled office or household is one with autonomous appliances, remote-operated thermostats, and fridges that monitor their contents and reorder supplies when they run low. You may never go hungry again.

There’s arguably an even brighter future for the IoT’s potential in industry – it can bring about value through applications like predictive maintenance and performance optimisation.

On paper these two scenarios – that of industrial optimisation and convenience throughout our daily lives – might seem worlds away. But James Robbins, Chief Information Officer at Drax, is thinking about how to bring them together – particularly when it comes to energy use.

Central to the approach is a question: could a better understanding of how households and businesses use energy change how it’s generated and provided?

The importance of data

At its heart, the IoT is about data. What data you collect and how you use it determines what value you can create, says Robbins. He explains: “Whether you’re talking about the IoT, big data, artificial intelligence [AI] or robotics – they’re all the modernisation of information collection and use.”

And nowhere is this more applicable than at a large-scale power station. “At Drax we’re used to managing what’s basically our own private IoT in the station,” he explains. “The real-time control systems we have for the generators and the Grid are essentially a bunch of sensors tied to a central network.” These sensors collect data from the power station, which then help optimise it for better performance.

The same approach to data collection can have benefits for bill payers, too.

Tracking energy use in the workspace and home

Connected devices like smart meters can bring a precise level of insight into energy usage in the home and places of work, which can benefit both end users and suppliers of heat and power. Electricity generators and heating fuel suppliers can use this data to better manage their output by being able to predict how and when it will be required. For end users, it can help them and their energy suppliers more accurately track what they use, where they use it and how they could use it more efficiently.

For example, using IoT technology a gas or wood pellet for heat supplier may be able to identify that a home can make substantial cost savings just by turning down their heating by one degree. “Sensors and smart technology can give us that insight,” says Robbins.

This level of optimisation is already possible to a degree using existing tools, but Robbins sees a future with greater possibilities. For example, with comprehensive datasets, suppliers can compare business owners’ energy use with others in the same sector and region to highlight efficiencies.

“The whole thing is about making it easier for us to serve the customer,” says Robbins. And the better the dataset, the more exotic the services could be.

“Just looking at meters means we can only really talk to the bill payer. But who else in the home or workplace could we engage with to get them to conserve energy? For instance, we could develop a game for child in the house that’s linked to energy use, where they get points for turning off lights or turning down heating,” he explains.

The gamification of energy use is – at this stage – just an idea, Robbins says, but it is exactly the kind of thing that better data allows energy suppliers and generators to think about.

A challenging journey, but an exciting one

The IoT approach to energy generation and use won’t be without its challenges – security being one major concern. But there will also be substantial technical and standardisation issues any provider keen to leverage IoT must tackle to make it a truly effective technology.

“In the 80s, you couldn’t play a VHS cassette in a Betamax player,” Robbins explains. “The compatibility issue with IoT could be an even bigger problem – all these gadgets need to be built into an architecture that can handle them and make them work together.”

Consider the so-called smart meter that provides data for a customer’s itemised bill. The bill payer is told that a tumble dryer in their home is using a significant proportion of the power they are paying for. The problem is that their appliances and devices have not been meshed together in a way that gives the system sufficient context about the customer’s situation. In the worst-case scenario, the customer asks for a refund and switches supplier because they don’t actually have a tumble dryer.

Robbins and his team are working with Drax suppliers to make sure that compatibility and context don’t become a problem. He aims to ensure that unintended consequences in the Group’s use of IoT are only of the positive variety. By investing in back-office infrastructure that can use big data processing to ingest and analyse meter data down to the 10-second level, Drax can take advantage of smart tech when it arrives in earnest.

It’s an exciting period of technological advancement – but as Robbins is keen to point out, it’s only the start.

“It’ll probably only be over the next few years that we actually begin to really understand how to leverage IoT data, when we pass the tipping point of user adoption. When that happens, we’ll be starting a very exciting journey with a clearer purpose – to spot and solve meaningful problems faced by people and businesses, in context, in real-time.”

Everything you ever wanted to know about cooling towers

17 May 2017

Power generation
Close up image of Drax cooling tower

Cooling towers aren’t beautiful buildings in the traditional sense, but it’s undeniable they are icons of 20th century architecture. They’re a ubiquitous part of our landscape – each one a reminder of our industrial heritage.

Yet despite the familiarity we have with them, knowledge about what a cooling tower actually does remains limited. A common misconception is that they release pollution. In fact, what they actually release is water vapour – similar to, but nowhere near as hot, as the steam coming out of your kettle every morning. And this probably isn’t the only thing you never knew about cooling towers. 

What does a cooling tower do?

As the name suggests, a cooling tower’s primary function is to lower temperatures – specifically of water, or ‘cooling water’ as it’s known at Drax.

Power stations utilise a substantial amount of water in the generation of electricity. At a thermal power plant, such as Drax, fuel is used to heat demineralised water to turn it to high pressure steam. This steam is used to spin turbines and generate electricity before being cooled by the cooling water, which flows through two condensers on either side of each of the steam turbines, and then returning to the boiler. It is this process that the cooling towers support – and it plays a pivotal role in the efficiency of electricity generation at Drax’s North Yorkshire site.

To optimise water utilisation, some power stations cycle it. To do this, they have cooling towers, of which at Drax there are 12. These large towers recover the warmed water, which then continues to be circulated where chemistry is permitting.

The warmed water (about 40°C) is pumped into the tower and sprayed out of a set of sprinklers onto a large volume of plastic packing, where it is cooled by the air naturally drawn through the tower. The plastic packing provides a large surface area to help cool the water, which then falls in to the large flat area at the bottom of the massive structure called the cooling tower pond.

As the water cools down, some of it (approximately 2%) escapes the top of the tower as water vapour. This water vapour, which is commonly mistakenly referred to as steam, may be the most visible part of the process but it’s only a by-product of the cooling process.

The majority of the water utilised by Drax Power Station is returned back to the environment, either as vapour from the top of the towers or safely discharged back to the River Ouse. Each year, about half of the water removed from the river is returned there. In effect, it is a huge amount of water recycling and in environmental terms, it is not a consumptive process.

Close-up of side of Drax cooling towers

How do you build a cooling tower?

The history of cooling towers as we know them today dates back to the beginning of the 20th century, when two Dutch engineers were the first to build a tower using a ‘hyperboloid’ shape. Very wide on the bottom, curved in the centre and flared at the top, the structure meant fewer materials were required to construct each tower, it was naturally more robust, and it helped draw in air and aid its flow upwards. It quickly became the de facto design for towers across the world.

The Dutch engineers’ tower measured 34 metres, which at the time was a substantial achievement, but as engineering and construction abilities progressed, so too did the size of cooling towers.

Today, each of 12 towers measures 115 metres tall – big enough to fit the dome of St Paul’s Cathedral or the whole of the Statue of Liberty, with room to spare. If scaled down to the size of an egg, the concrete of each cooling tower would be the same thinness as egg shell.

The structures at Drax are dwarfed by the cooling towers at the Kalisindh power plant in Rajasthan, India, the tallest in the world. Each stands an impressive 202 metres tall – twice the height of the tower housing Big Ben and just a touch taller than the UK’s joint fifth tallest skyscraper, the HSBC Tower at 8 Canada Square in London’s Canary Wharf.

The industrial icon of the future

Today’s energy mix is not what is used to be. The increased use of renewables means we’re no longer as reliant on fossil fuels, and this has an effect on cooling towers. Already a large proportion of the UK’s most prominent towers have been demolished, going the same way as the coal they were once in service to. But this doesn’t mean cooling towers will disappear completely.

Power stations such as Drax, which has upgraded four of its boilers to super-heat water with sustainably-sourced compressed wood pellets instead of coal, the dwindling coal fleet, and some gas facilities still rely on cooling towers. As they continue to be part of our energy mix, the cooling tower will remain an icon of electricity generation for the time being. But it’ll be a mantle it shares with biomass domes, gigantic offshore wind turbines and field-upon-field of solar panels – the icons of today’s diverse energy mix.

View our water cooling towers close up. Drax Power Station is open for individual and group visits. See the Visit Us section for further information.

Inside the machine shop

24 April 2017

Power generation

A klaxon sounds and a crane big enough to lift 160 tonnes moves slowly across the inside of a cavernous warehouse. Below, a team of engineers stand around a turbine spindle the size of a double decker bus but weighing four times as much at 65 tonnes, waiting for the crane’s descent.

Around them, other engineers work on similar-sized equipment. One uses a wrench the size of an arm. Another programs a computerised lever to carefully strip millimetres from a piece of steel. It’s just a normal day inside Drax Power Station’s machine workshop.

For the last 15 years, this workshop has been refurbishing, repairing and manufacturing tools and equipment for use at the power station – a fact that sets Drax apart from other stations like it.

“We’re envied by a few stations because we do most things in-house,” says Turbine Engineer and head of the workshop, Andrew Storr. “We’re leagues in front of everyone else in the UK because we’ve got our own manufacturing and machining facility. We can do all this work on site. We’re not relying on other people.”

Storr set up the workshop in 2001 after being asked to reverse engineer a replacement set of governor relays (components that help regulate the flow of steam going into the turbines) for one of Drax’s steam turbines. Today, it’s a thriving centre of activity filled with heavy-duty machinery and ingenious engineers.

A look inside the workshop

“When you’re manufacturing spares it’s not a matter of going down to our machine shop and just saying ‘make one of those’. You’ve got to have the correct grade of material, the correct size, the correct certification for the material – you can’t just have a scrappy piece of steel that you find. It’s got to have paperwork with it to say it’s certified up to whatever it’s supposed to be,” says Storr.

Turbine bearings need to be bored to size using a horizontal borer that very accurately shaves out the lining of the inner bearing. Getting it right is incredibly important, explains Storr: “If it’s made too large it causes the turbine shaft to vibrate. If it’s made too small the bearing becomes too hot and the white metal will melt and pour out the bearing. We need to avoid both of these issues at all cost.”

The inside of the turbine blading needs to have seal strips administered by hand as they’re delicately made to limit any damage to the spinning shaft should they touch each other. Despite the wealth of equipment at the disposal of the team in the shop, success depends on the skill of the engineers using it.

There are three 160-tonne cranes in the turbine hall, each installed before the turbines were built. This meant the construction companies who erected the turbines could lift all heavy components into place with ease. “Due to their size they move slowly. It takes approximately 20 minutes for the largest hook to travel from the ground all the way to the top,” says Storr.

“In mechanical engineering it’s sometimes necessary to fit one part inside another, and once these parts are assembled they must stay locked together and not come apart,” Storr says. One way the team does this is by shrinking some components, and for this they use liquid nitrogen.

The team places the component that needs to fit inside another into a bath of liquid nitrogen and shrink it at -190 degrees Celsius. Once shrunk, the team assembles the two, placing the now smaller component into the larger one. “Eventually the inner part warms up to ambient temperature and grows in size, making the fit very tight and preventing them from coming apart,” explains Storr.

In the past, Drax would send the work they now do in the machine shop to companies off site. And because all other power stations in the area would do the same thing, wait times would often be long and the quality of the output could vary.

“When we do it in-house I can keep my eye on it,” says Storr. “I can re-prioritise things depending on what is going to be needed back on the turbine first – we’ve got 100% control over it. We can make sure everything’s hunky-dory.”