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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.”

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.

15 words foresters use

16 August 2017

Sustainable bioenergy
Wind-shaped tree in a field

In Japanese, there’s a single word to describe sunlight filtering through the leaves of a tree: komorebi. It’s a poetic term to describe an image almost everyone recognises, however English has no direct translation.

But while English lacks a ‘komorebi’ equivalent, it does contain a significant number of words that speak to the very specific features of the forestry industry – terms that describe the crooked nature of a tree open to the elements on a mountain side, or words for the process of stripping a grown tree of its limbs.

Here, we look at the unusual, the uncommon, and the whimsical words that make up the language of forestry.

Silviculture

Seen as both a science and an art, silviculture is the practice of controlling the establishment, growth, composition, health and quality of forests. This goes beyond just managing working forests for wood products markets, however, and includes those dedicated to everything from leisure to wildlife.

Comminution

One of the first steps in the production of biomass such as wood pellets is reducing down the raw materials like the fresh felled green wood, and this relies on a process known as comminution. This is carried out by a range of specifically designed machinery such as rotary hammer mills, chippers and grinders, but can also be done in the forest using mobile chippers to reduce tops and branches.

Krummholz

From the German word ‘krumm’ meaning crooked, bent or twisted, krummholz is a term for trees that are stunted and sculpted by harsh winds found near the tree line of mountains, or on coastlines where there are large quantities of salt in the air. Exposure to the elements often means these trees are windblown into surreal shapes, while branches on one side are often deformed or dead.

Underdog

A key component of any sports movie, the origins of the word underdog may actually have come from the logging industry.

In pre-mechanised times, logs would be placed over a sawpit and cut up the middle with a long two-handled saw. The unfortunate sawyer working at the bottom, often knee deep in rainwater, under a falling rain of sawdust, was known as an underdog. However, other theories exist which claim the term originates from dog fighting.

A hypsometer

A hypsometer, used to measure angles to determine the height of trees

Hypsometer

A hypsometer is a tool used to measure angles. When used by foresters, it can determine the height of a tree. To use it, foresters measure the top and bottom of the tree from a measured distance away and use trigonometry to calculate the height.

Hoppus foot

The standard measurement of volume used for timber across the British Empire, the hoppus foot was introduced by English surveyor Edward Hoppus in 1736. The imperial measurement was developed to estimate how much squared, useable timber could be converted from a round log, while allowing for wastage.

A mobile wood chipper

A mobile wood chipper in operation in Arkansas

Slash and brash 

Slash and brash are both terms for the woody debris left by logging operations. However, while slash can be chipped and sold as biomass, brash is not normally removed. Instead, it can be spread along routes used by forestry machinery to prevent ground damage in what are known as brash mats.

Leader

The very top stem of a tree. This typically develops from a tree’s ‘terminal bud’, which is the main area of growth in a plant and is found at the end of a limb.

Two men using a cart to transport a log

Foresters using horses and rail carts to transport timber in California, 1904

Hot logging

Hot logging is the process of loading logs onto lorries and removing them from forests immediately after felling – when they’re still hot from the saw. This is in contrast to the more common process of storing or decking logs on site before removing. Hot logging is often used when ‘whole tree harvesting’, as the trees are removed from site and processed at the mill to maximise recovery of high value saw timber material.

Snag  

Dead trees might not seem like the most useful plants in a forest, but snags prove otherwise. Snags are standing dead or dying trees, and they serve an important role in forest ecosystems. Often missing their top or most of their smaller branches, snags provide habitats for wide varieties of birds, mammals and invertebrates, as well as supporting decomposers such as fungi. In fresh water environments snags also make essential shelter for fish spawning sites.

Beating up

Towards the end of the growing season, trees that have died shortly after planting are counted and replanted in what is known as beating up. This process also allows foresters to identify and address any issues that may have affected growth.

Thinning

A staple of responsible forestry, thinning is the practice of periodically removing a proportion of trees from a forest to reduce competition and provide the healthiest, most valuable trees with greater access to water, sunlight and nutrients. As well as opening up more resources for the remaining trees, this process also provides feedstock for the biomass and paper industries.

Rotation

In managed forests, foresters keep a range of different age trees to ensure a constant flow of healthy and mature wood. Rotation is the term for the number of years required between new planting (typically of seedlings) and final harvesting. In the US south rotations of plantation pine are commonly about 25 years, and 45 years for naturally regenerated pine, while in the UK this is closer to 60. For the same species in even more northerly Finland rotations are typically between 80 and 90 years.

Snedding

Coming from the Scandinavian word snäddare, meaning smooth log, snedding is the process of stripping shoots and branches from a branch or felled tree. Known as limbing in US, snedding is carried out with by chainsaws or more heavy-duty harvesters and stroke delimbers.

Mensuration

How to you measure the total wood of a forest? Mensuration, that’s how. Mensuration is a form of mathematics that allows foresters to measure the volume of standing or felled timber. It is an important tool in not only the quantifying of how much product there is to sell, but in monitoring and managing the health and growth of a forest.

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.

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.”

3 ways decarbonisation could change the world

27 June 2017

Sustainable business

Mitigating climate change is a difficult challenge. But it’s one well within the grasp of governments, companies and individuals around the world if we can start thinking strategically.

On the behalf of the German government, The Internal Energy Agency (IEA) and the International Renewable Energy Agency (IRENA) have jointly published a report outlining the long-term targets of a worldwide decarbonisation process, and how those targets can be achieved through long-term investment and policy strategies.

At the heart of the report is a commitment to the ‘66% two degrees Celsius scenario’, which the report defines as, ‘limiting the rise in global mean temperature to two degrees Celsius by 2100 with a probability of 66%’. This is in line with the Paris Agreement, which agreed on limiting global average temperature increase to below two degrees Celsius.

Here are three of the findings from the report that highlight how decarbonisation could change the world.

The energy landscape will change – and that’s a good thing

Decarbonisation will by definition mean reducing the use of carbon-intensive fossil fuels. Today, 81% of the world’s power is generated by fossil fuels. But by 2050, that will need to come down to 39% to meet the 66% two degrees Celsius scenario, according to the report. But, this doesn’t mean all fossil fuels will be treated equally.

Coal will be the most extensively reduced, while other fossil fuels will be less affected. Oil use in 2050 is expected to stand at 45% of today’s levels, but will likely still feature in the energy landscape due its use in industries like petrochemicals.

Gas will likely also remain a key part of the energy makeup, thanks to its ability to provide auxiliary grid functions like frequency response and black-starting in the event of grid failure.

Renewables like biomass will likely play an increasing role here as well, particularly when combined with carbon capture and storage (CCS) technology.

Overall, renewable energy sources will need to increase substantially. In the report’s global roadmap for the future, renewables make up two thirds of the primary energy supply. Reaching this figure will be no mean feat – it will mean renewable growth rates doubling compared with today.

Everyday electricity use will become more efficient 

The report highlights the need for ‘end-use’ behaviour to change. This can mean everyday energy users choosing to use a bit less heat, power and fuel for transport in our day-to-day activities, but a bigger driver of change will be by investment in better, more efficient end-use technology – the technology, devices and household appliances we use every day.

In fact, the study argues that net investment in energy supply doesn’t need to increase beyond today’s level – what needs to increase is investment in these technologies. For instance, by 2050, 70% of new cars must be electric cars to meet decarbonisation targets.

Infrastructure design could also be improved for energy efficiency – smart grids, battery storage and buildings retrofitted with energy efficient features such as LED lighting will be essential. There’s also the possibility of increased use of cleaner building materials and processes – for example, constructing large scale buildings out of wood rather than carbon-intensive materials such as concrete and steel.

Decarbonisation will cost, but not decarbonising will cost more

The upfront costs of meeting temperature targets will be substantial. A case study used in the report estimates that $119 trillion would need to be spent on low-carbon technologies between 2015 and 2050. But it also suggests another $29 trillion may be needed to meet targets.

However, failure to act could mean the world will pay out an even higher figure in healthcare costs, or in other economic costs associated with climate change, such as flood damage or drought. Therefore, the sum for decarbonisation could end up costing between two and six times less than what failing to decarbonise could cost.

On top of this, the new jobs (including those in renewable fuel industries that will replace those lost in fossil fuels) and opportunities that will be created between 2015 and 2050 could add $19 trillion to the global economy. More than that, global GDP could be increased by 0.8% in 2050, thanks to added stimulus from the low carbon economy.

Achieving a cleaner future won’t be easy – it requires planning, effort, and the will to see beyond short-term goals and think about the long-term benefits. But as the report demonstrates, get it right and the results could be considerable.

What is a working forest?

1 June 2017

Sustainable bioenergy
An illustration of a working forest

For centuries, civilizations have relied on forests and forest products. Forests provided fuel, food and construction materials, and there were plenty of them.

But when, in 18th century Europe, the needs of growing industrialisation sent development into overdrive, a problem arose: forests were struggling to meet demand.

In Germany, the problem was acute. The growing steel industry had increased demand for wood to power its smelters and for wood used in mining operations. Large areas of forestland were stripped to meet industry’s needs and overall supply was quickly decreasing.

No one was more acutely aware of the challenge than Hans Carl von Carlowitz, who at the time was the head of the Saxon mining administration.

So, in 1713 he published ‘Silvicultura Oeconomica’, a book which advocated the conservation and management of German forests so they could provide for industries in the long term. Although he drew on existing knowledge from around Europe, it was the first time an important term was used: Nachhaltigkeit, the German word for sustainability.

Carlowitz explained this new term: “Conservation and growing of wood is to be undertaken in order to have a continuing, stable and sustained use, as this is an indispensable cause, without which the country in its essence cannot remain.”

It was arguably the start of the scientific approach to forestry, and although our needs of forests have changed (as have the words we use to describe them – working forest, plantation forest and managed forest all refer to largely the same thing), that same principle is at the heart of how a modern working forest functions: to ensure what exists and is useful today will still be there tomorrow.

This approach relies on responsible forest management, which sets out a few key principles on how a forest should be managed to sustain its life.

Providing room to breathe

Working forests are commonly managed to produced sawlogs – high value wood that can be sawn to make timber for construction or furniture. For a forester to optimise the quality and quantity of sawlogs, regular thinning is required. Thinning is the process of periodically felling a proportion of the forest to aid its overall health and vigour. This means there are fewer trees fighting for the same resources (water, sunshine, soil). More than that, thinning can promote diversity by providing more light and space for other flora.

Thinning can occur several times in a forest’s cycle. It can be used to increase the size and quality of the remaining trees and also to encourage new seedlings to establish in place of the harvested trees when managing for continuous forest cover.

Nothing should be wasted

The roundwood produced by thinning is often too small to be sold as sawlogs, but that doesn’t mean it’s worthless. It can be sold to the pulp industry to make paper, or for particleboard or to the biomass industry to make compressed wood pellets, which can be used to fuel power generation – as is done at Drax Power Station. These industries also provide a market for the lower grade roundwood removed when the more mature trees are finally harvested.

In areas where there was no robust market for this low grade wood, it would often be left on site and become a fire risk or a haven for pest and disease attack. Too much low grade material left on site can also inhibit the regrowth of the next tree crop. So markets for this material are important for the health of the forest and the value of the land to the forest owner. Also in the Baltic countries markets for pulpwood are limited and the energy sector provides a valuable opportunity to clear the site for replanting and provide additional revenue to the forest owner.

This process of utilising all parts of the forest is essential for a healthy working forest. On the one hand, the revenue can cover the cost of thinning. This husbandry enhances the quality of the final tree crop and ensures that money is available to invest in future planting and regeneration, ensuring the forest area is consistently maintained and improved.

Red Pine, Pinus resinosa - thinned plantation with natural seedlings

Young regeneration in a shelterwood system, demonstrating the continuous forest lifecycle

The carbon benefits of a working forest

Rather than diminishing it, actively managing a forest helps its ability to sequester – or absorb and store – more carbon.

Carbon sequestration is directly related to the growth rate of a tree – a young, growing tree absorbs more carbon dioxide (CO2) from the atmosphere than an older one. Older trees will have more carbon stored (after a ‘childhood’ spent absorbing it), but if these are not harvested they are more susceptible to fire damage, pests and diseases and their carbon absorption plateaus.

In an actively managed forest, older trees ready for sawlog production can be harvested and replaced with vigorously growing young trees and in the process maximise the CO2 absorption potential of the forest.

The by-products of this process – the low grade wood and thinnings – can be used for the pulp and biomass industry, which both aids the health of the remaining forest, and provides revenue for the forester to invest in the long term life of his or her forest.

Three centuries of sustainability

In the 300 years since Carlowitz published his book on sustainability a lot has changed. And while it’s unlikely he foresaw forests providing fuel for renewable electricity and renewable heat, the approach remains as relevant.

What is a working forest? It is one that is as productive and healthy tomorrow as it is today. That we’re using the same resource today as we were 300 years ago is evidence to suggest it’s a practice that works.

4 amazing uses of bioenergy

5 April 2017

Sustainable bioenergy
Large modern aircraft view of the huge engine and chassis, the light of the sun

Bioenergy is the world’s largest renewable energy source, providing 10% of the world’s primary supply. But more than just being a plentiful energy source, it can and should be a sustainable one. And because of this, it’s also a focus for innovation.

Biomass currently powers 4.8% of Great Britain’s electricity through its use at Drax Power Station and smaller power plants, but this isn’t the only way bioenergy is being used. Around the world people are looking into how it can be used in new and exciting ways.

algal blooms, green surf beach on the lakePowering self-sufficient robots 

What type of bioenergy?

Algae and microscopic animals

How’s it being used?

To power two aquatic robots with mouths, stomachs and an animal-type metabolism. Designed at the University of Bristol, the 30cm Row-Bot is modelled on the water boatman insect. The other, which is smaller, closer resembles a tadpole, and moves with the help of its tail.

Both are powered by microbial fuel cells – fuel cells that use the activity of bacteria to generate electricity – developed at the University of the West of England in Bristol. As they swim, the robots swallow water containing algae and microscopic animals, which is then used by their fuel cell ‘stomachs’ to generate electricity and recharge the robots’ batteries. Once recharged, they row or swim to a new location to look for another mouthful.

Is there a future?

It’s hoped that within five years the Row-Bot will be used to help clean up oil spills and pollutants such as harmful algal bloom. There are plans to reduce the tadpole bot to 0.1mm so that huge shoals of them can be dispatched to work together to tackle outbreaks of pollutants.

multi-coloured water ketttlesPurifying water

What’s used?

Human waste

How’s it being used?

The Omni Processor, a low cost waste treatment plant funded by the Bill and Melinda Gates Foundation, does something incredible: it turns sewage into fresh water and electricity.

It does this by heating human waste to produce water vapour, which is then condensed to form water. This water is passed through a purification system, making it safe for human consumption. Best of all, it does this while powering itself.

The solid sludge left over by the evaporated sewage is siphoned off and burnt in a steam engine to produce enough electricity to process the next batch of waste.

Is there a future?

The first Omni Processor was manufactured by Janicki Bioenergy in 2013 and has been operating in Dakar, Senegal, since May 2015. A second processor, which doubles the capacity of the first, is currently operating in Sedro-Woolley, Washington, US and is expected to be shipped to West Africa during 2017.

Closer to home and Drax Power Station, a similar project is already underway. Northumbrian Water was the first in the UK to use its sludge to produce renewable power, but unlike the Omni Processor, it uses anaerobic digestion to capture the methane and carbon dioxide released by bacteria in sludge to drive its gas turbines and generate power. Any excess gas generated is delivered back to the grid, resulting in a total saving in the utility company’s carbon footprint of around 20% and also multi-millions of pounds of savings in operating costs.

Jet plane leaves contrail in a sunset beautiful sky, copy space for textFlying across the Atlantic

What’s used?

Tobacco

How’s it being used?

Most tobacco is grown with a few factors in mind – taste and nicotine content being the most important. But two of the 80 acres of tobacco grown at Briar View Farms in Callands, Virginia, US, are used to grow tobacco of a very different sort. This tobacco can power aeroplanes.

US biofuel company Tyton BioEnergy Systems is experimenting with varieties of tobacco dropped decades ago by traditional growers because of poor flavour or low nicotine content. The low-nicotine varieties need little maintenance, are inexpensive to grow and flourish where other crops would fail.

The company is turning this tobacco into sustainable biofuel and last year filed a patent for converting oil extracted from plant biomass into jet fuel.

Is there a future?

In the hope of creating a promising source of renewable fuel, scientists are pioneering selective breeding techniques and genetic engineering to increase tobacco’s sugar and seed oil content.

In 2013, the US Department of Energy gave a $4.8m grant to the Lawrence Berkeley National Laboratory, in partnership with UC Berkeley and the University of Kentucky, to research the potential of tobacco as a biofuel.

Fukushima Japan

Powering repopulation of a disaster zone

What’s used?

Wood exposed to radiation by the Fukushima nuclear meltdowns

How’s it being used?

Last year it was announced that German energy company Entrade Energiesysteme AG, will set up biomass power generators in the Fukushima prefecture that will generate electricity using the lightly irradiated wood of the area.

It’s hoped they will help Japan’s attempts to repopulate the region following the 2011 earthquake, tsunami and nuclear accident. Entrade says its plants can reduce the mass of lightly irradiated wood waste by 99.5%, which could help Japanese authorities reduce the amount of contaminated material while at the same time generating sustainable energy.

Is there a future?

The prefecture aims to generate all its power from renewable energy by 2040 through a mix of bioenergy and solar power.

Sustainability, certified

24 March 2017

Sustainable bioenergy
Drax Morehouse woodchip truck

Of all the changes to Drax Power Station over the last decade, perhaps the biggest is one you can’t see. Since converting three of its six generating units from coal to run primarily on compressed wood pellets, Drax has reduced those units’ greenhouse gas (GHG) emissions by over 80%.

And while this is a huge improvement, it would mean nothing if the biomass with which those reductions are achieved isn’t sustainably sourced.

For this reason, Drax works with internationally-recognised certification programmes that ensure suppliers manage their forests according to environmental, social and economic criteria.

Thanks to these certification programmes, Drax can be confident it is not only reducing GHG emissions, but supporting responsible forestry from wherever wood fibre is sourced.

Sustainability certifications

The compressed wood pellets used at Drax Power Station come from various locations around the world, so Drax relies on a number of different forest certification programmes, the three main ones being the Sustainable Forest Initiative (SFI), Forest Stewardship Council® (FSC®)1 and the Programme for the Endorsement of Forest Certification (PEFC).

The programmes share a common goal of demonstrating responsible forest management, but adoption rates vary by region. European landowners and regulators are most familiar with the FSC and national PEFC standards, while North American landowners generally prefer SFI and American Tree Farm System (also members of the PEFC family). In instances in which Drax sources wood pellets carrying these certifications, or in instances in which Drax purchase pellets sourced from certified forests, these certifications offer an additional degree of assurance that the pellets are sustainable.

Over 50% of the pellets used at Drax Power Station come from the southern USA, where SFI and American Tree Farm System are the most widely implemented certification programmes. Overall adoption levels in this region are relatively modest. However, the SFI offers an additional level of certification that can be implemented by wood-procuring entities, such as sawmills, pulp mills and pellet mills.

This programme is referred to as SFI Fiber Sourcing, and to obtain it, participants must demonstrate that the raw material in their supply chains come from legal and responsible sources. These sources may or may not include certified forests. The programme also includes requirements related to biodiversity, water quality, landowner outreach and use of forest management and harvesting professionals. Together, these certification systems have long contributed to the improvement of forest management practices in a region that provides Drax with a significant proportion of its pellets.

And since the SFI and ATFS programmes are endorsed by PEFC, North American suppliers have a pathway for their region’s sustainable forest management practices to be recognised by European stakeholders.

These certification programmes have been in use for many years. But with recent growth in the market for wood pellets, a new certification system has emerged to deal specifically with woody biomass.

Trees locked up in a bundle

New kid on the block

The Sustainable Biomass Program (SBP) was set up in 2013 as a certification system to provide assurance that woody biomass is sourced from legal and sustainable sources. But rather than replacing any previous forest certification programmes, it builds on them.

For example, SBP recognises the evidence of sustainable forest management practices gathered under these other programmes. However, the PEFC, SFI and FSC programmes do not include requirements for reporting GHG emissions, a critical gap for biomass generators as they are obligated to report these emissions to European regulators. SBP fills this gap by creating a framework for suppliers to report their emissions to the generators that purchase their pellets.

When a new entity, such as a wood pellet manufacturer, first seeks certification under SBP, that entity is required to assess its supply base.

Feedstock which has already been certified by another established certification programme (SFI, FSC®, PEFC or PEFC approved schemes) is considered SBP-compliant.

All other feedstock must be evaluated against SBP criteria, and the wood pellet manufacturer must carry out a risk assessment to identify the risk of compliance against each of the 38 SBP indicators.

If during the process a specific risk is identified, for example to the forest ecosystem, the wood pellet manufacturer must put in place mitigation measures to manage the risk, such that it can be considered to be effectively controlled or excluded.

These assessments are audited by independent, third party certification bodies and scrutinised by an independent technical committee.

In conducting the risk assessment, the wood pellet manufacturer must consult with a range of stakeholders and provide a public summary of the assessment for transparency purposes.

Sustainable energy for the UK

Counting major energy companies including DONG Energy, E.ON and Drax as members, the SBP has quickly become an authoritative voice in the industry. At the end of 2016, the SBP had 74 certificate holders across 14 countries – including Drax’s pellet manufacturing arm, Drax Biomass, in Mississippi and Louisiana.

It’s a positive step towards providing the right level of certification for woody biomass, and together with the existing forestry certifications it provides Drax with the assurance that it is powering the UK using biomass from legal and sustainable sources.

Like the fast-reducing carbon dioxide emissions of Britain’s power generation sector, it’s a change you can’t see, but one that is making a big difference.

Read the Drax principles for sustainable sourcing.

1 Drax Power Ltd FSC License Code: FSC® – C119787