Tag: biomass energy

Giving up coal

Tony Juniper at Drax Power Station between coal stock and biomass wood pellet storage domes

Tony Juniper* is an environmental campaigner, author and director at Robertsbridge, a consultancy helping advise Drax on its sustainability programmes

Back in 2006 while working as Director at Friends of the Earth I approved a new report to be published in support of our then campaign for a new Climate Change Act. We wanted to show UK government ministers how it would indeed be possible to make cuts in emissions so that by 2050 the UK could progressively have reduced greenhouse gas pollution by 80 per cent compared with emissions in 1990. It was a radical and demanding agenda that we’d adopted and it was important to show the practical steps that could be made in achieving it.

The analysis we presented was based on an electricity sector model that we had developed. Different data and assumptions could be inputted and using this we set out six possible lower carbon futures.

In our best case scenario we foresaw how it would be feasible to slash emissions by about 70 per cent by 2030.

This was based on an ambitious energy efficiency programme and a shift away from fossil energy and toward renewables, including wind and solar power. In that renewables mix was also an important role for biomass to replace coal in the country’s largest power station – Drax.

This was not only crucial for backing up intermittent renewable sources but also a key piece in a future electricity sector that we believed should avoid the construction of new nuclear power stations. In November 2008 our campaign succeeded and the UK was the first country in the world to adopt a new national law for the science-based reduction of greenhouse gas emissions. Since then I’ve been working as an independent sustainability advisor, including with the advisory group Robertsbridge, of which I was a co-founder.

My work has included assisting various companies in meeting the targets set out in that new law. For example, I was the Chair of the industry campaign Action for Renewables which sought government and public support for the large-scale expansion of wind, tidal and wave power.

Different campaigners tried to stop the expansion of these renewable sources of electricity, however, and succeeded in derailing support for on-shore wind power developments.

Although in its infancy, concerns were also raised about proposals for different kinds of tidal power.

In the years after the Climate Change Act I was encouraged to see that Drax began to switch over to wood pellets to generate power but concerned to see that this too had come under attack. The broadly agreed view that sustainable biomass could have a role in the phase out of coal had gone, and in its place were claims  that it was actually worse than burning coal. It was against this backdrop of changed perspectives that myself and Robertsbridge colleagues were pleased to be invited to help Drax in devising a new sustainability plan.

Early on in our conversations with Drax it became clear that part of the challenge with biomass — deciding the extent to which it is a rational choice to help with the process of decarbonisation, is how the answer to that touches so many different issues.

For example, when it comes to the exit from coal, cleaner alternatives must be brought forward to replace it, including wind and solar power.

But although these sources of renewable energy are growing rapidly, they still come with their own challenges, especially because wind can’t generate on still days and solar ceases at night. This intermittency raises issues about what the best electricity storage or complementary clean power sources might be to back them up when needed.

There are important questions about the best sources of biomass and the extent to which long-distance transport of that fuel is desirable. On top of that are issues linked with the management of the forests from which the raw material is sourced, and whether the extraction of wood to generate power can be compatible with carbon neutrality. There is the matter of nature conservation and the extent to which wood fuel demand will affect the status of species and habitats of conservation concern. For example, to what extent might the wood pellet industry be driving the conversion of semi-natural woodlands to plantations?

All of this is bound up with the economic and social conditions prevailing in the landscapes from which the wood is derived and the extent to which those buying wood fuel can pursue positive outcomes for the environment, even when carbon and wildlife are at best of marginal concern to the local forest owners growing the wood.

Then there is the extent to which economic incentives might be linked with the carbon stocks held in the forest. For example, strong demand for wood is held to be the main reason why since the 1950s the volume of carbon stored in standing timber in the forests of the US South has increased by over 100%.

Demand for wood might seem counter-intuitive as a positive factor in maintaining tree cover, but in the US South it has been a big part of the picture.

On top of all this is the question of what would happen if there were no demand for wood fuel. In landscapes that have seen volatility in demand arising from the decline in newsprint in favour of digital devices and the slowdown in US house building following the 2008 financial crisis, this is not easy to answer.

Although seeking answers is a complex task, our advice to Drax was that it should work with its many stakeholders in finding the best possible fit between its business planning and these and other questions.

One way of doing that would be to set out the different issues in an accessible manner and hence the production of the film that can be seen here.

It’s called ‘The biomass sustainability story And while most of us can agree with the basic idea that we have to stop burning coal, it seems the big questions are about what might be the best ways to do it? Might biomass have a role? I believe it does.

Have a look at the film and see what you think, especially if you feel as though you’ve already made up your mind.

The people-powered renewables revolution

For decades the electricity system was relatively straightforward. Power was generated by utility companies, then sold and supplied to consumers and businesses. But this is changing and the power industry may be on the verge of a revolution.

The falling costs and ongoing innovation around technologies like rooftop solar panels and domestic battery storage is enabling the rise of so-called ‘prosumers’ – individuals, businesses or institutions who not only consume electricity, but produce it too.

According to the National Grid’s 2017 Future Energy Scenarios report, this could lead to an almost entirely decentralised, cleaner energy system.

But for this to happen, prosumerism needs to be adopted at scale, and this relies on technological innovation and changes to attitudes and behaviours.

The technology powering prosumers

The biggest barrier to large-scale adoption of prosumerism is technology. Although research and innovation pounds, dollars and euros have been pouring into the technologies that make decentralised power generation possible, there are still developments to be made.

Solar is one of the most prominently used renewables by prosumers thanks to the relative affordability of rooftop solar systems. Even home-interior giant IKEA now offers solar panels and battery systems through a partnership with the UK’s largest solar company, Solarcentury.

But like wind turbines (a more cost-prohibitive solution) solar is an intermittent energy source, which means domestic users may still need to access the grid to fill gaps in their own generation. That is, unless battery technology advances to a point where it can store enough solar- or wind-generated electricity to fully power homes and businesses affordably – all-year round, including in the dark, still days of midwinter.

Until then, a prosumer who wants to have a reliable, flexible self-supply of energy needs to be able to call on a mix of renewable technologies – just as the national system does. Hamerton Zoo in Cambridgeshire, for example, generates its own energy via a mix of solar, wind and biomass. It then sells its excess electricity to an energy supplier.

There are signs that battery technology is starting to take off as an option for powering homes and businesses. Tesla’s Powerwall is currently the closest home battery system to breaking through to mainstream consumers and many firms are following its lead. For example, in the UK, Elon Musk’s company faces new competition from Nissan, which is partnering with US power firm Eaton to build and sell home batteries in the UK. That two electric car manufacturers are in on the act is no surprise – it will be another revolution, that of electric vehicles (EVs) usurping the dominance of petrol and diesel models that is set to bring the boon that batteries need to become a popular choice for prosumers.

The government is also pushing innovation in the space with business and energy secretary Greg Clark announcing plans to invest £264 million into research in the sector over the next four years.

Energy ownership

But what could this mean for the business of electricity? The National Grid report suggests multiple ‘commercial models’ will operate together to facilitate a decentralised, prosumer-based energy system.

These would include homes and businesses who wholly own their energy systems, as well as systems owned and operated by third parties such as aggregators managing energy or solar-rental schemes.

Community-owned projects could also play a role, with small renewable energy facilities supplying residents, such as the wind turbine in the Cambridgeshire village of Gamlingay. Excess energy could also be sold back to the grid with any money earned reinvested in the community, or in its renewable infrastructure.

Similar schemes are already in place in both the business and consumer retail markets. In 2016, for example, Opus Energy – a Drax Group company supplying energy to UK businesses – bought almost 1 TWh of power from over 2,000 small renewable generators who use technologies such as anaerobic digestion, solar, onshore wind and hydro. Opus Energy then sells that power onto its predominantly small and medium-sized enterprise (SME) customer base. This allows it to offer innovative tariffs such as the 100% solar power deal enjoyed by restaurant chain LEON this summer.

Haven Power, the Drax retail business specialising in electricity supply for large corporate and industrial clients, sells on power from over 20 small renewable generators – and it has a number of large clients such as water utilities who self-generate a lot of their own power and work with Haven Power to help manage their self-supply against their demand from regional electricity distribution networks (and further upstream, National Grid and power stations).

For large power generators, an increase in prosumerism in the energy sector could mean likely overall demand may decrease, which would mean a scaling back of operations. However, the increased volatility of the grid will give rise to the need for flexibility and for additional ancillary services like frequency response, which ensures the country’s electricity is all operating at the same frequency.

This would most likely be delivered by flexible generators (such as gas and biomass), which would also be required for winter demand, when more electricity is required and there is less wind and solar generation.

The role of government incentives

Another key part of the rise of consumer generated power will be government regulation and incentive schemes. In the UK, new measures have been put in place to encourage individuals to generate their own electricity.

These intend to make it easier for prosumers to generate their own power through solar, store it in batteries and sell it back to the National Grid, something which regulator Ofgem claims could save consumers between £17 billion and £40 billion by 2050. This isn’t the only scheme of its kind currently in action.

The UK’s Renewable Heat Incentive (RHI) encourages homeowners and businesses to adopt low-carbon heating, offering to pay a certain amount for every kWh of renewable heat generated. Feed-in tariffs, on the other hand, also offer financial incentives, with electricity suppliers paying prosumers for the energy they produce themselves.

Is my home or business big enough?

The prosumer revolution will not happen overnight. Self-generation and self-storage of power and the installation of renewable heat systems are more suited to larger properties or those linked up to community-based projects, so for many people living in properties they own, rent or in social housing the idea of becoming a prosumer could right now be a little far-fetched.

And although there is evidence that the national transmission grid is already decentralising, nor will this revolution mean the complete eradication of all centralised utilities.

Through gradual improvements in small-scale energy generation, power storage, smart technology and government policies, it will become an increasingly affordable and efficient way for communities, businesses and institutions to go green.

Active management of forests increases growth and carbon storage

A study on the historical trends in the forest industry of the US South, carried out by supply chain consultancy Forest2Market, and commissioned by Drax Group, the National Alliance of Forest Owners and the U.S. Endowment for Forestry and Communities, found that over the last 60 years, as demand for forestry products has increased, the productivity of the area’s forests has increased too. In short, the more we’ve come to use them, the more forests have grown.

A forest is not like a mine – there is not a finite amount of wood in the ground that disappears when it is extracted, never to return. Forests are a renewable resource that can be replanted, improved, and harvested for as long as the land is managed responsibly.

What’s more, landowners have a strong financial incentive to not only maintain their holdings but to improve their productivity – after all, the more of something you have, the more of it you have to sell. It is an economic incentive that works.

Six decades of growth

The Forest2Market report found that increased demand for wood is statistically correlated with more annual tree growth, more wood volume available in the forest, and more timberland.

For example, between 1953 and 2015, tree harvests increased by 57%, largely driven by US economic growth and increased construction. Over the same period, annual wood growth increased by 112%, and inventory increased by 108%. In total, annual growth exceeded annual removals by 38% on average.

Annual forest growth in the US South increased from 193 million cubic metres in 1953 to 408 million cubic metres in 2015. Inventory increased from 4 billion to 8.4 billion cubic metres.

The forest products industry funded private-public research projects to enhance the quality and performance of seedlings and forest management practices to ensure a stable supply of wood. Because of these efforts, landowners saw the value of active management techniques, changing their approach to site preparation, fertilization, weed control, and thinning, and the use of improved planting stock. Healthy demand made it easy for landowners to take a long-term view, investing in more expensive management practices up front for greater returns in the future. And the results were extraordinary: seedlings established in the last 20 years have helped plantations to become nearly four times as productive as they were 50 years ago.

A changing market

Markets for wood have changed over the last two decades, precipitated by decreased demand for writing paper and newsprint, increased demand for absorbent hygiene products and containerboard and increased demand for biomass. These changes in demand have not impacted the way that landowners manage timberland, however. As sawtimber (the largest trees in the forest) remains the most valuable timber crop, it also remains the crop the landowners want to grow. Pulpwood is harvested from the forest only when the forest is being thinned to create optimal conditions for growing sawtimber or when sawtimber is harvested and the forest is being cleared for replanting.

Pellet production has expanded rapidly in the US South, though its overall footprint is still small in comparison to more traditional forest product industries.

In some local wood basins, however, like the one surrounding Bastrop, Louisiana (the location of one of Drax’s US production facilities), the use of biomass to create pellets has filled a gap left by the closure of an 80-year old paper mill. Drax’s decision to locate in this area is integral to supporting forest industry jobs and landowners who carefully consider local demand when deciding whether to continue growing trees.

According to Tracy Leslie, Director of Forest2Market’s biomaterials and sustainability practice, “As history has shown, forests in the US South have benefitted from increased demand for all types of wood. The rise of the pulp and paper industry did not detract from landowner objectives to maximize production of higher value sawtimber nor did it result in a shift in focus to growing only pulpwood. This new demand did, however, provide landowners with important interim and supplemental sources of income. Forest2Market’s research shows that an increase in demand for pellets will have the same effect, incentivizing landowners to grow and re-grow forests, increasing both forest inventory and carbon storage.”

The real threat to forests

Not only does demand for forest products increase the productivity and carbon storage of forests and provide an incentive for landowners to continue growing trees, but it also helps counter factors that irrevocably destroy this natural resource. The real threat to forests in the US is not demand for wood, but urbanisation. Nearly half of all US forestland that converted to another use between 1982 and 2012 was cleared for urban development.

Commercial forestry protects forested lands from development; between 1989 and 1999, just 1% of managed pine plantations in the US South were cleared for non-forest development compared to 3% of naturally-regenerated forest types.

Urbanisation, not the forest products industry, places the most pressure on forests in the US South. Forest2Market’s findings demonstrate that demand associated with healthy timber markets promotes the productivity of forests and mitigates forest loss by encouraging landowners to continue to grow, harvest, and regenerate trees.

Read the full report: Historical Perspective on the Relationship between Demand and Forest Productivity in the US South. An At A Glance version plus an Executive Summary are also available as a separate documents.

 

This is how you unload a wood chip truck

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.”

How many homes can we power with renewables?

Terraced houses at night time on portland dorset

More of Britain’s electricity is coming from renewables than ever before. New offshore wind farms, solar capacity hitting double figures and the reliability of biomass are having a marked effect on the country’s power.

Our electricity make up is more diverse than ever. More than this, it is cleaner. During the first three months of 2017, emissions from power generation were 10% lower than the same period last year and 33% lower than the first quarter of 2015.

And while this is a huge and necessary step in the UK’s efforts towards slowing global warming, it would mean little if renewables weren’t also keeping our lights on. That’s exactly what they are doing – powering businesses, industries and homes across the country. But how many, exactly?

The scale of renewables

In 2015 the total electricity consumption of the UK was 303 TWh. To put that into perspective, that’s roughly enough power to boil 121.1 billion kettles. A quarter of the 360 TWh of electricity generated that year  came from renewables – 84 TWh – a massive 29% increase over 2014. Of that figure, Drax’s biomass units contributed 11.5 TWh, approximately 3% of that year’s total power generation.

So, renewables are big, but how big?

Panoramic photo of modern house with outdoor and indoor lighting, at night

According to the 2011 Census there are 26.4 million households in the UK. Ofgem, the energy regulator, says the average UK household uses roughly 3.1 MWh of electricity a year (the average US household uses approximately 10.8 MWh).

If we were to hypothesise that all the renewable power generated in 2015 had been consumed by UK households, there would be enough to power every single one. And there’d be enough left over to power 600,000 more.

Using just the power generated thanks to sustainably sourced compressed wood pellets at Drax Power Station would be enough to satisfy the equivalent of 4.1 million homes – nearly twice the number of households in Scotland or 800,000 more homes than in the whole of London. 15% of all UK homes could have been powered by just half that one station in Selby, North Yorkshire.

Finding the right mix for the future

Electricity is used to power more than just homes. It powers businesses, transport and infrastructure – almost all parts of our lives are fuelled by electricity. While there may be the hypothetical equivalent to power every single household in the UK with renewables (with room to spare), the reality is there is a far larger nationwide demand that needs to be fulfilled. And this means we can’t rely on renewables alone. Instead, what’s required is an energy mix that also includes other low carbon sources of electricity – backed up by a new fleet of gas power stations and storage that can respond rapidly to changes in demand.

While we’re not yet in a position where we can power all homes all the time using renewables, that day could well be coming. A new report from the International Renewable Energy Agency (IREA) suggests a mix of renewable technologies including biomass and bioenergy with carbon capture and storage (BECCS) could meet the majority of global energy demand across all sectors of the world economy by 2050 – while helping to keep the rise in global temperatures to under two degrees celsius above 1990 levels.

Everything you ever wanted to know about cooling towers

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.

Why you shouldn’t be surprised by another record-breaking quarter for renewable energy

Field of solar panels shot from above

It’s been another record-breaking quarter for Britain’s power system. During the first three months of 2017, biomass, wind and hydro all registered their highest energy production ever, while solar recorded its highest ever peak output.

And while this is all worth celebrating, it shouldn’t come as a surprise – the last few years have seen Britain’s power system take several significant steps toward decarbonisation and this year is no different. Electric Insights, the quarterly report on Britain’s power system by Dr Iain Staffell from Imperial College London, commissioned by Drax via Imperial Consultants, documents the new gains and confirms the trend: renewables are fast becoming the new norm and in 2017 they continued their growth.

Biomass domes at Drax Power Station

The renewable record breakers

Over this quarter biomass electricity generation hit a record production figure of 4.4 TWh, which means that biomass generators ran at 95% of full capacity – higher than any other technology has achieved over the last decade.

Hydro went 4% better than its previous energy production best by generating 1.6 TWh, while Britain’s wind farms produced 11.3 TWh (10% higher than the previous record, set in 2015). This was helped in part by several new farms being built which increased installed capacity by 5% over last year, but it was also indebted to the mild, windy weather.

Wind farms produced more electricity than coal, 57 days out of 90 during the first three months of 2017

Solar hit a new record peak output at the end of March, when it generated 7.67 GW – enough to power a fifth of the country. In fact, during the last weekend of March, for the first time ever, the country’s demand for electricity from the national grid was lower during an afternoon than during the night. This was because solar panels, which only generate power when the sun is up, tend to sit outside of the national high voltage transmission grid.

Understanding how this happened is to understand how solar energy is changing our national power system.

A reverse of the trend

Electricity demand on the national grid – think of it as the power system’s motorways – is typically higher during the day and early evening (when people are most active, using lights and gadgets) than overnight. However, on the last weekend in March 2017, the opposite was true because of how much solar energy was generated.

Solar panels and some smaller onshore windfarms are ‘invisible’ – they don’t feed into the national grid. Instead, these sources either feed into the regional electricity distribution networks – the power system’s A and B roads – or, as many of them are on people’s roofs and used in their own homes or business premises, it never gets down their driveway. This can mean when solar panels are generating a lot of electricity, there is a lower demand for power from the grid, making it appear that less of the country is using electricity than it actually is.

This was the case during the last weekend of March, when solar generated enough power to satisfy a large part of Britain’s demand. And while this is another positive step towards a lower carbon energy mix, it is about to change the way our power system works, particularly when it comes to the remaining coal power stations.

What the power system needs to provide, today and in the future, is flexibility – to ramp up and down to accommodate for the shifting demand based on supply of intermittent – weather dependent – renewables. Thermal power stations such as gas, coal and biomass can meet much of this demand, but even more rapid response from technologies such as the Open Cycle Gas Turbines that Drax is developing and batteries could fulfil these needs quicker.

Today’s dirty is yesterday’s clean

The record breaking and increased renewable generation of the period from January to March 2017 would mean nothing if it wasn’t matched by a decrease in emissions. During the first three months of 2017, emissions dropped 10% lower than the same period in 2016 and a massive 33% lower than 2015. Coal output alone fell 30% this quarter compared to Q1 2016.

To put the scale of this progress into context we need only look at the quarter’s ‘dirtiest hour’ – the hour in which carbon intensity from electricity generation is at its highest. Between January and March, it peaked on a calm and cold January evening with 424 grams of CO2 released per kWh (g/kWh). The average for generation between 2009 and 2013 was 471 g/kWh. In short, this quarter’s dirtiest hour was cleaner than the average figure just four years ago – yesterday’s average is today’s extremity.

If we want to continue to break records and further progress towards a fully decarbonised power system, this needs to be a consistent aim: making the averages of today tomorrow’s extremes.

Top line stats

Highest energy production ever

  • Wind – 11.3 TWh
  • Biomass – 4.4 TWh
  • Hydro – 1.6 TWh

Record peak output

  • Solar – 7.67 GW
  • Enough to power 1/5 of the country

Yesterday’s average is today’s extremity

  • Average carbon emissions per kWh – 2009-2013
    • 471 g/kWh
  • Average carbon emissions per kWh – Q1 2017
    • 284 g/kWh
  • Peak carbon emissions per kWh – 2009-2013
    • 704 g/kWh
  • Peak carbon emissions per kWh – Q1 2017
    • 424 g/kWh

 

Explore the data in detail by visiting ElectricInsights.co.uk

Commissioned by Drax, Electric Insights is produced independently by a team of academics from Imperial College London, led by Dr Iain Staffell and facilitated by the College’s consultancy company – Imperial Consultants.

How space tech helps forests

Satellite view of the Earth's forests

Can you count the number of trees in the world? Accurately, no – there are just too many, spread out over too vast an area. But if we could, what would we gain? For one, we would get a clearer picture of what’s happening in our planet’s forests.

They’re a hugely important part of our lives – not only for the resource they provide, but for their role in absorbing carbon dioxide (CO2). So properly understanding their scale and what is happening to them – whether increasing or decreasing – and designing strategies to manage this change is hugely important.

The trouble is, they exist on such a vast scale that we traditionally haven’t been able to accurately monitor them en masse. Thanks to space technologies, that’s changing.

A working forest

The view from up there

As far back as World War II, aerial imaging was being used to monitor the environment. In addition to using regular film cameras mounted to aeroplanes to follow troops on the ground, infrared film was used to identify green vegetation and distinguish it from camouflage nets.

As satellite and remote sensing technology developed through the 20th century, so too did our understanding of our planet. Satellites were used to map the weather, monitor the sea, and to create topological maps of the earth, but they weren’t used to track the Earth’s forests in any real detail.

But in 2021 the European Space Agency (ESA) will launch Biomass, a satellite that will map the world’s forests in unprecedented detail using the first ever P-band radar to be placed in Earth orbit. This synthetic aperture radar penetrates the forest canopy to capture data on the density of tree trunks and branches. It won’t just be able to track how much land a forest covers, but how much wood exists in it. In short, the Biomass will be able to ‘weigh’ the world’s forests.

Over the course of its five-year mission, it will produce 3D maps every six months, giving scientists data on forest density across eight growth cycles.

The satellite is part of ESA’s Earth Explorers programme, which operates a number of satellites using innovative sensor technology to answer environmental questions. And it’s not the only entity carrying out research of this sort.

California-based firm Planet has 149 micro-satellites measuring just 10cm x 30cm in orbit around the Earth, each of which beams back around three terabytes of data every day. To put it another way, each satellite photographs about 2.5 million square kilometres of the Earth’s surface on a daily basis.

The aim of capturing this information is to provide organisations with data to help them answer the question: what is changing on Earth? When it comes to forests, this includes identifying things like illegal logging and forest fires, but the overall aim is to create a searchable, expansive view of the world that enables people to generate useful insights.

Rocket flying over the earth

Keeping the world green

All this data is not only vital for developing our understanding of how the world is changing, it is vital for the development of responsible, sustainable forestry practices.

From 2005 to 2015, the UN rolled out the REDD programme (Reducing Emissions from Deforestation and forest Degradation), which, among other functions, allows countries to earn the right to offset CO2 emissions – for example through forestry management practices. Sophisticated satellite measurement techniques not only let governments know the rate of deforestation or afforestation in their respective countries, it can also help them monitor, highlight and encourage responsible forestry.

Satellite technology is increasingly growing the level of visibility we have of our planet. But more than just a clearer view on what is happening, it allows us the opportunity to see why and how it is happening. And it’s with this information that real differences in our future can be made.