Tag: investors

How lasers reduce emissions

25 July 2017

Power generation
Drax laser

Of the air that makes up our atmosphere, the most abundant elements are nitrogen and oxygen. In isolation, these elements are harmless. But when exposed to extremely high temperatures, such as in a power station boiler or in nature such as in lightning strikes, they cling together to form NOx.

NOx is a collective term for waste nitrogen oxide products – specifically nitric oxide (NO) and nitrogen dioxide (NO2) – and when released into the atmosphere, they can cause problems like smog and acid rain.

At a power station, where fuel is combusted to generate electricity, some NOx is inevitable as air is used in boilers to generate heat. But it is possible to reduce how much is formed and emitted. At Drax Power Station, a system installed by Siemens is doing just that.

It begins with a look into swirling clouds of fire.

Not your average fireplace

“Getting rid of NOx is, at heart, a problem of getting combustion temperatures to a point where they are hot enough to burn fuel effectively. Too hot and the combustion will form excess amounts of NOx gases. Too cool and it won’t combust efficiently,” says Julian Groganz, a Process Control Engineer who helped install the SPPA-P3000 combustion optimisation system at Drax. “Combustion temperatures are the result of the given ratio of fuel and air in each spot of the furnace. This is our starting point for optimisation.”

An industrial boiler works in a very different way to your average fireplace. In Drax’s boilers, the fuel, be it compressed wood pellets or coal, is ground up into a fine powder before it enters the furnace. This powder has the properties of a gas and is combusted in the boilers.

“The space inside the boiler is filled with swirling clouds of burning fuel dust,” says Groganz. Ensuring uniform combustion at appropriate temperatures within this burning chamber – a necessary step for limiting NOx emissions – becomes rather difficult.

Heat up the cold spots, cool down the hotspots

If you’re looking to balance the heat inside a boiler you need to understand where to intervene.

The SPPA-P3000 system does this by beaming an array of lasers across the inside of the boiler. “Lasers are used because different gases absorb light at different wavelengths,” explains Groganz. By collecting and analysing the data from either end of the lasers – specifically, which wavelengths have been absorbed during each beam’s journey across the boiler – it’s possible to identify areas within it burning fuel at different rates and potentially producing NOx emissions.

For example, some areas may be full of lots of unburnt particles, meaning there is a lack of air causing cold spots in the furnace. Other areas may be burning too hot, forcing together nitrogen and oxygen molecules into NOx molecules. The lasers detect these imbalances and give the system a clear understanding of what’s happening inside. But knowing this is only half the battle.

A breath of fresher air

“The next job is optimising the rate of burning within the boiler so fuel can be burnt more efficiently,” explains Groganz. This is achieved by selectively pumping air into the combustion process to areas where the combustion is too poor, or limiting air in areas which is too rich.

“If you limit the air being fed into air-rich, overheated areas, temperatures come down, which reduces the production of NOx gases,” says Groganz. “If you add air into air-poor, cooler areas, temperatures go up, burning the remaining particles of fuel more efficiently.”

Drax Laser 2

It’s a two-for-one deal: not only does balancing temperatures inside the boiler limit the production of NOx gases, but also improves the overall efficiency of the boiler, bringing costs down across the board. It even helps limit damage to the materials on the inside the boiler itself.

Thanks to this system, and thanks to its increased use of sustainable biomass (which naturally produces less NOx than coal), Drax has cut NOx emissions by 53% since the solution was installed. More than that, it is the first biomass power station to install a system of this sophistication at such scale. This means it is not just a feat of technical and engineering innovation, but one paving the way to a cleaner, more efficient future.

What’s next for bioenergy?

11 July 2017

Sustainable bioenergy
Morehouse BioEnergy in Louisiana

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

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

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

Future one: Failure to act on climate change

Dams on river

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

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

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

Future two: Growing a stable, centralised bioenergy

Rows of saplings ready for planting

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

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

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

Future 3: The right mix bioenergy

Modern house with wind turbine

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

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

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

4 of the most exciting emerging technologies in electricity generation

6 July 2017

Power generation
Petri dish with microbe colony

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

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

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

Microbial fuel cells – harnessing the power of bacteria

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

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

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

Building with sun shining through glass windows

Solar – a new dawn

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

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

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

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

Nuclear reactor hall in a power plant

Betavoltaics – nothing wasted from nuclear waste

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

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

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

Ocean wave crashing at shore

Tidal power – changing tides

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

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

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

This is how you unload a wood chip truck

30 June 2017

Sustainable bioenergy
Truck raising and lowering

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

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

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

What is a tipper?

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

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

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

close-up of truck raising and lowering

How does it work?

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

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

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

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

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

Efficiency benefits

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

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

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

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

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.

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.

How space tech helps forests

20 April 2017

Sustainable bioenergy
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.

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.

The biomass carbon story

Matthew Rivers, Director of Corporate Affairs, Drax, Group Special Advisor

23 February 2017

Sustainable bioenergy

There is an important difference between carbon dioxide (CO2) emitted from coal (and other fossil fuels) and CO2 emitted from renewable sources. Both do emit CO2 when burnt, but in climate change terms the impact of that CO2 is very different.

To understand this difference, it helps to think small and scale up. It helps to think of your own back garden.

One tree, every year for 30 years

Imagine you are lucky enough to have a garden with space for 30 trees. Three decades ago you decided to plant one tree per year, every year. In this example, each tree grows to maturity over thirty years so today you find yourself with a thriving copse with 30 trees at different stages of growth, ranging from one year to 30 years old.

At 30 years of age, the oldest has now reached maturity and you cut it down – in the spring, of course, before the sap rises – and leave the logs to dry over the summer. You plant a new seedling in its place. Through the summer and autumn the 29 established trees and the new seedling you planted continue to grow, absorbing carbon from the atmosphere to do so.

Winter comes and when it turns cold and dark you burn the seasoned wood to keep warm. Burning it will indeed emit carbon to the atmosphere. However, by end of the winter, the other 29 trees, plus the sapling you planted, will be at exactly the same stage of growth as the previous spring; contain the same amount of wood and hence the same amount of carbon.

As long as you fell and replant one tree every year on a 30-year cycle the atmosphere will see no extra CO2 and you’ll have used the energy captured by their growth to warm your home. Harvesting only what is grown is the essence of sustainable forest management.

If you didn’t have your seasoned, self-supplied wood to burn you might have been forced to burn coal or use more gas to heat your home. Over the course of the same winter these fuels would have emitted carbon to the atmosphere which endlessly accumulates – causing climate change.

Not only does your tree husbandry provide you with an endlessly renewable supply of fuel but you also might enjoy other benefits such as the shelter your trees provide and the diversity of wildlife they attract.

Mushroom - Brown cap boletus in autumn

No added carbon

This is a simplified example, but the principles hold true whether your forest contains 30 trees or 300 million – the important point is that with these renewable carbon emissions, provided you take out less wood than is growing and you at least replace the trees you take out, you do not add new carbon to the atmosphere. That is not true with fossil fuels.

It is true that you could have chosen not to have trees. You could instead build a wind turbine or install solar panels on your land. That would be a perfectly reasonable choice but you’ll still need to use the coal at night when the sun doesn’t shine or when the wind isn’t blowing. Worst of all you don’t get all the other benefits of a thriving forest – its seasonal beauty and the habitat that’s maintained for wildlife.

Of course, the wood Drax needs doesn’t grow in our ‘garden’. We bring it many miles from areas where there are large sustainably managed forests and we carefully account for the carbon emissions in the harvesting, processing and transporting the fuel to Drax. That’s why we ‘only’ achieve more than 80% carbon savings compared to coal.