Author: admin

Securing reliable and flexible energy this winter

20 October 2017

Power generation

Preparing for winter is one of the UK power system’s biggest challenges. Shorter days and falling temperatures ramp up demand for electricity and gas to power lights and heating across the country. This can put strain on the grid, even leading to blackouts if not carefully managed.

In anticipation of potentially difficult times, National Grid assesses Britain’s winter energy system to determine how much power we’re going to need, and more importantly, to ensure generators can produce enough to meet demand.

In its most recent report looking at winter 2017/18, National Grid’s take is a positive one: there will be enough power to meet demand. More than that, it has the potential to be cleaner than ever before.

What to expect from electricity this winter

In the report, National Grid forecasts a surplus power margin (how much generation capacity will exceed estimated demand) of 10.3% – a significant increase from last year’s 5.7% margin.

What does this mean in real terms? The report predicts a peak electricity demand of nearly 51 GW during the darkest, coldest days of mid-December. By contrast, the total possible capacity of the UK’s energy system during winter is 101.2 GW, not including interconnectors importing power from abroad.

It is important to note, however, that 101.2 GW is more a theoretical number than an expected one. Considering normal occurrences such as planned outages, breakdowns, or other operational issues that prevent power stations generating their usual output, a more accurate estimate is 66.1 GW.

But electricity isn’t the only resource put under strain in the winter months – gas is also in high demand for heating and for electricity generation. In the report, National Grid predicts this winter to have a lower gas demand than last year, owing largely to a decrease in gas-fuelled electricity generation. However, where gas-fired electricity is likely to remain integral is in plugging the gaps in electricity supply left by intermittent renewables.

The system under stress

Weather plays a huge part in both the consumption and generation of power. During the winter, when days are shorter and darker, and the wind calmer, solar and wind cannot generate and feed into the power grid as they normally would.

This means when there are sudden spikes in demand (such as in a cold snap), National Grid must secure other sources to avoid disruption, which can sometimes include carbon-intensive coal, diesel generators, or importing power from Europe.

This growing pressure on the system requires flexible and reliable sources of energy that can quickly react to these sudden surges.

“Biomass is a reliable, flexible renewable and available at scale. It’s able to provide the full range of support services the grid needs to retain stable supplies – whatever the weather,” says Drax Power CEO, Andy Koss.

Drax Power Station’s south cooling towers recycle water and feed it back into the boilers, where 17% of the UK’s renewable electricity is generated

Low-carbon winter energy

The ability to secure sufficient, reliable and lower-carbon power over the winter months is key to the ongoing decarbonisation of the UK. Biomass and gas will play an important role in allowing the country to operate with less dependence on fossil fuels.

We’ve already made significant headway in this field. Last year, Christmas Day was powered by more renewable electricity than ever before, while each quarter of 2017 has seen new clean energy records broken.

As we move into another winter, it’s imperative generators and operators focus on the security of supply. That the stability of our power system will be secured by lower carbon sources is an added – and much needed – bonus.

Keeping the options open

19 October 2017

Sustainable bioenergy

Roughly 750 million acres of the US is covered in forestland – an area nearly 12 times the size of the UK. Approximately two-thirds of that land is working timberland, producing wood used for construction and furniture. In short, US forestry is a massive industry.

Enviva is the world’s largest wood pellet producer and biggest biomass supplier to Drax Power Station, but in the context of the US forestry industry in which it operates, Enviva does things differently.

“We’re leading the industry in sustainability and transparency in our sourcing practices,” says Jennifer Jenkins, Vice President and Chief Sustainability Officer at Enviva. “We’ve created unique tracking systems and we conduct science-based sourcing, both of which encourage sound forest stewardship.”

Specifically, Enviva draws on best practices to make decisions about which areas it sources from and how it protects the areas it doesn’t.

Protecting bottomland forests

A bottomland forest is an area of low-lying marshy area near rivers or streams that can be home to unique tree and wildlife species. These forests are flooded periodically and they can be ecologically important. However, they’re also a part of south-eastern America’s working forest landscape.

In fact, Enviva sources 3-4% of its wood from these areas, but only where harvesting improves the life of the forest. For example, in some cases, harvesting mimics naturally occurring storms, clearing the canopy so young seedlings and forest floor species thrive. More than that, harvesting can also help keep forests as forests.

“In the areas where we work, one of the biggest threats to forests is being converted to another use – specifically to developed or agricultural land,” explains Dr. Jenkins. “Our goal is to keep forests as forests. We want to preserve those with the highest risk of being converted for another use.” If landowners can gain a steady income from regular harvests, they’re likely to keep their land as working forests.

However, this is only true for carefully assessed forests where harvesting is deemed safe. Any land that doesn’t meet Enviva’s set of strict criteria means Enviva won’t source from it – it can simply walk away. The landowners, on the other hand, don’t have that luxury.

“Isn’t it our responsibility to provide another option for a landowner who might not want to facilitate a harvest?” asks Dr. Jenkins. “Maybe they recognize its value. Maybe they would prefer to conserve it instead. In recognition of our responsibility, we made a commitment.”

A fund that keeps forests as forests

Enviva’s commitment was to partner with the US Endowment for Forestry & Communities to set up the Enviva Forest Conservation Fund, a $5 million, 10-year programme designed to protect tens of thousands of acres of sensitive bottomland forests in the Virginia-North Carolina coastal plain.

It works by inviting submissions from projects looking to protect areas of high conservation value. Last year it awarded its first round of funding to four projects. More recently, in June 2017, the Enviva Forest Conservation Fund announced a total of $500,000 to go toward a second round of projects with partners such as Ducks Unlimited, an organization which – with the grant – plans to acquire more than 6,000 acres of wetlands to operate as a public Wildlife Management Area.

The Fund follows a history of proactive sustainability programmes, including a strict supplier assessment process and the company’s Track & Trace tool, a one-of-a-kind publicly-accessible system that tracks every ton of primary wood Enviva purchases back to the forest from which it was sourced. It is entirely transparent and is a testament to Enviva’s commitment to sustainability and doing things differently.

As Dr. Jenkins explains, this approach stems back to the origins of the company in 2004: “As a company that makes wood pellets, Enviva’s reason for being is to help lower greenhouse gas emissions. An emphasis on sustainability has always been a part of Enviva’s DNA.”

7 things to see at Drax Power Station

4 October 2017

Power generation

Chimneys taller than the London Eye, domes bigger than the Albert Hall and enough steel tubing to run the length of the UK twice, Drax Power Station is a structure of superlatives. But it’s visiting the site that truly drives home the scale of the electricity generating process.

From tiny biomass pellets to landscape-shaping cooling towers, here are seven of the most-impressive and interesting parts of Drax Power Station.

Cooling towers

Arguably the power station’s most recognisable landmarks, Drax’s 12 giant cooling towers each measure 114 metres tall. To put that in perspective, each is large enough to fit the entire Statue of Liberty inside it – with room to spare.

These massive concrete structures cool the water used as part of the generation process. Water is pumped into the tower at roughly 40 degrees Celsius and is cooled by air naturally pulled into the structure by its unique shape. Once the water is cooled it is safely returned to the River Ouse.

So, what’s coming out the top of a cooling tower? Water vapour, and it only accounts for roughly 2% of all the water pumped into the tower.

Biomass domes

Standing 65 metres tall, Drax’s four biomass domes are each larger than the Royal Albert Hall and between them hold approximately 300,000 tonnes of compressed wood pellets – enough to power Leeds, Manchester, Sheffield and Liverpool for more than 12 days.

Each dome was constructed by inflating a massive PVC dome, coating its inside with a layer of polyurethane foam, and then adding steel and concrete reinforcements. Because of the sensitive nature of compressed wood pellets, the environment inside each dome must be very carefully monitored. One of the measures to keep the biomass inert is to feed in nitrogen (extracted from the air) into the dome.

Rail unloading bay

Coal’s days traversing the UK by train are almost numbered – biomass is taking over its routes. Compressed wood pellets arrive to English shores at the ports of Liverpool, Hull and Immingham and are then transported across the country in specially designed trains. Roughly 14 arrive every day, collectively unloading about 20,000 tonnes of pellets.

Drax’s bespoke wagons ensure the wood pellets are kept dry during transportation and unloaded as efficiently as possible. This includes a hatch on the bottom of the wagons that is opened magnetically to drop the pellets down into the collection area as they arrive.

Turbine hall

Here’s where the magic happens – it’s in the turbine hall that electricity is generated. Biomass is fast replacing coal to be combusted to produce steam, which is used to spin massive electromagnets at 3,000 rpm inside copper windings, which in turn generates electricity.

With each of the six turbines capable of exporting over 600 megawatts (MW) into the National Grid, the total capacity of Drax Power Station sits just shy of 4,000 MW, 70% of which now comes from sustainable biomass – an impressive 17% of Great Britain’s renewable electricity from this one, epic site.

Control room

The nerve centre of the power station, data from across the plant is fed into the control room, giving engineers a view of every stage of the generation process. The information displayed across the web of dials and screens around the room shows data on temperatures, levels or positioning of equipment, and enables operators to monitor and adjust activity around the plant.

This command and control centre at the heart of Drax Power Station is off the beaten track of most tours – so if seeing it is top of your list, please say-so on the tour booking form. As impressive as the control room and on the regular tour is the Queen’s Gallery, giving a birds-eye view over the turbine hall.

Visitor centre 

First port of call on a tour of Drax Power Station, the visitor centre offers an interactive history of Drax, from when construction began in the 1960s, via coal’s decline as a fuel source and through to the modern, predominantly-biomass power plant of today.

It’s here that visitors can step inside the electricity generation process and learn from Drax’s experienced guides about what happens at the heart of the UK’s largest power plant.

The Skylark Centre and Nature Reserve

Away from the noise of the turbine hall, a weekend trip to Drax also offers the chance to enjoy a peaceful walk through a unique natural environment. The Skylark Centre and Nature Reserve, Drax is home to more than 100 species of wildlife, including rare and endangered varieties guests might encounter along the reserve’s nature walks.

The centre offers the chance to learn more about this environment, its inhabitants and the unique story of its creation. The reserve is spread across Barlow Mound, a structure created as a means of safely storing the ash created in burning coal at the power station. More than 301 million m3 of ash is safely stored in the current site, on top of which grasses and trees have been planted to allow nature to thrive.

Its reinvention into an area of natural beauty reflects the power station’s own transformation away from coal.

Public tours of and visits to Drax Power Station are currently suspended. The suspensions are to reduce the risk to business-critical areas of our operation. We are planning to resume tours and visits in 2021, but we cannot guarantee this at the present time. Please check our website for the latest information and virtual tours.

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.

Longleaf Pine: how wood product markets help to conserve a protected species

22 September 2017

Sustainable bioenergy

Longleaf pine forests were once a dominant ecosystem across the Southern US’ Gulf and Atlantic states, spanning from the east coast in Virginia as far west as Texas. However, centuries of overuse and conversion to agriculture and to faster growing pine species mean today less than 5% of the estimated 90 million acres remain.

Restoration of the longleaf pine savanna is now underway and the careful management of both public and private forests is key to preserving this ecosystem. Wood product and biomass markets play an important role in this, ensuring there is an economic incentive for landowners to plant high-value longleaf pines and manage them in a way that promotes conservation.

An ecosystem shaped by fire

The ancient abundance of longleaf pines across the southern US owes to their highly pyrophytic nature, meaning they are resistant to fire. This allowed the trees to survive both the naturally occurring forest fires from summer thunderstorms and those started as land management by native Americans. These regular fires help give the longleaf savanna its distinctive features, with a limited canopy providing ample sunlight and allowing grasses and herbs to grow in the nitrogen-rich soil.

As colonial settlements expanded across North America, the long straight timber offered by the pines, as well as the resin and turpentine, made these forests a valuable resource. Longleaf pine ecosystems reached a depleted state.

The restoration push

Today, America’s Longleaf Restoration Initiative (ALRI) is taking strides to restore the species. The collaborative effort between public and private sector partners has set a 15-year goal of increasing longleaf acreage from 3.4 million to 8.0 million acres by 2025. 

These ecosystems are currently home to an estimated 900 endemic plants and 29 federally listed species including the red-cockaded woodpecker, gopher tortoise and indigo snake.

Restoring the environment in which the flora and fauna can flourish is not as simple as planting large numbers of longleaf pine trees.

“Conservation efforts must focus on not only the planting of the pine, but also the restoration, development, and maintenance of the pine savanna ecosystem,” says Kyla Cheynet, a forest ecologist at Drax Biomass. “This system requires predictable disturbance to maintain the open canopy and rich herbaceous vegetation.”

The role of the wood product market

These disturbances include prescribed fires and the careful harvesting of trees to ensure the landscape maintains its open canopy that allows plenty of sunlight to reach the grasses and other vegetation along the forest floor.

The ALRI’s 2016 report highlighted the importance of thinning and prescribed fires in conserving longleaf savanna. It found that while new planting of longleaf pines declined slightly (8%) from 2015, the wildlife quality, plant diversity and overall health of forests improved by removing competing tree species and allowing more sunlight to enter the forest.

Harvesting or thinning longleaf pine forests provides a small percentage of the fibre used to manufacture compressed wood pellets used at Drax Power Station, but these markets help to incentivise responsible forest management and offer a source of profit for landowners. These revenue-generating practices are crucial to ensuring the continued survival of longleaf pine forests by preventing them from being converted to agricultural land or lost to development.

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.

The silent force that moves electricity

31 August 2017

Power generation

In the early evening of 14th August 2003, New York City, in the midst of a heatwave, lost its power. Offices, stores, transport networks, Wall Street and the UN building all found their lights and phones cut off. Gridlocked streets and a stalled subway system forced millions to commute home on foot while those unable to make it back to the suburbs set up camp around the city.

It wasn’t just the Big Apple facing blackout – what had started with several power lines in Northern Ohio brushing against an overgrown tree had spread in eight minutes to affect eight US states and two Canadian provinces. In total, more than 50 million people were impacted, $6 billion was lost in damages and 12 deaths were reported.

While a software glitch and the outdated nature of the power system contributed to the disaster, the spread from a few high-voltage power lines to the entire North West was caused by a lack of reactive power.

The pump powering electricity

Electricity that turns on light bulbs and charges phones is what’s known as ‘active power’ — usually measured in Watts (W), kilowatts (kW), megawatts (MW) or in even higher units. However, getting that active power around the energy system efficiently, economically and safely requires something called ‘reactive power’, which is used to pump active power around the grid. Reactive power is measured in mega volt amps reactive (MVAr).

It’s generated in the same way as active power by large power stations, but is fed into the system in a slightly different manner, which leads to limitations on how far it can travel. Reactive power can only be effective locally/regionally – it does not travel far. So, across the country there are regional reactive power distributors servicing each local area (imagine a long hose pipe that needs individual pumps at certain points along the way to provide the thrust necessary to transport water).

But power stations aren’t the only source of reactive power. Some electronic devices like laptops and TVs actually produce and feed small amounts of reactive power back into the grid. In large numbers, this increases the amount of reactive power on the grid, and when this happens power stations must absorb the excess.

This is because, although it’s essential to have reactive power on the grid, it is more important to have the right amount. Too much and power lines can become overloaded, which creates volatility on the network (such as in the New York blackout). Too little and efficiency decreases. Think, once again, of the long hose pipe – if the pressure is too great, the hose is at risk of bursting. If the pressure is too low, water won’t travel through it properly.

This process of managing reactive power is, at its heart, one of ensuring active power is delivered to the places it needs to be. But it is also one of voltage control – a delicate balancing act that, if not closely monitored, can lead to serious problems.

Keeping volatility at bay

Across Britain, all electricity on the national grid must run at the same voltage (either 400kV or 275kV – it is ‘stepped down’ from 132kV to 230V when delivered to homes by regional distribution networks). A deviation as small as 5% above or below can lead to equipment being damaged or large scale blackouts. National Grid monitors and manages the nationwide voltage level to ensure it remains within the safe limit, and doing this relies on managing reactive power.

Ian Foy, Head of Ancillary Services at Drax explains: “When cables are ‘lightly loaded’ [with a low level of power running through them], such as overnight when electricity demand is lower, they start emitting reactive power, causing the voltage to rise.”

To counter this, generators such as Drax Power Station, under instruction from National Grid, can change the conditions in their transformers from exporting to absorbing reactive power in just two minutes.

This relies on 24-hour coordination across the national grid, but as our power system continues to evolve, so do our reactive power requirements. And this is partly down to the economy’s move from heavy industry to business and consumer services.

The changing needs for reactive power

“Large industrial power loads, such as those required for big motors, mills or coal mines, bring voltage down and create a demand for more reactive power,” explains Foy. “Now, with more consumer product usage, the demand for active power is falling and the voltage is rising.”

The result is that Drax and other power stations now spend more time absorbing reactive power rather than exporting it to keep voltage levels down. In the past, by contrast, Foy says the power plant would export reactive energy during the day and absorb it at night.

As Britain’s energy system decarbonises, the load on powerlines also becomes lighter as more and more decentralised power sources such as wind and solar are used to meet local demand, rather than large power plants supplying wider areas.

This falling load on the power system increases the voltage and creates a greater need for generators to absorb reactive power from the system. It highlights that while Drax’s role in balancing reactive power has changed, it remains an essential service.

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, system inertia, frequency response 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.