Author: David Drummond

What is biomass?

21 August 2020

Sustainable bioenergy
Illustration of a working forest supplying biomass

What is biomass?

In ecological terms, biomass refers to any type of organic matter. When it comes to energy, biomass is any organic matter that can be used to generate energy, for example wood, forest residues or plant materials.

How is biomass used?  

Biomass used and combusted for energy can come in a number of different forms, ranging from compressed wood pellets – which are used in power stations that have upgraded from coal – to biogas and biofuels, a liquid fuel that can be used to replace fossil fuels in transport.

The term biomass also refers to any type of organic material used for energy in domestic settings, for example wood burned in wood stoves and wood pellets used in domestic biomass boilers.

Biomass is organic matter like wood, forest residues or plant material, that is used to generate energy.

Where does biomass come from?

Biomass can be produced from different sources including agricultural or forestry residues, dedicated energy crops or waste products such as uneaten food.

Drax Power Station uses compressed wood pellets sourced from sustainably managed working forests in the US, Canada, Europe and Brazil, and are largely made up of low-grade wood produced as a byproduct of the production and processing of higher value wood products, like lumber and furniture.

Biomass producers and users must meet a range of stringent measures for their biomass to be certified as sustainable and responsibly sourced.

Key biomass facts

Is biomass renewable?

 Biomass grown through sustainable means is classified as a renewable source of energy because of the process of its growth. As biomass comes from organic, living matter, it grows naturally, absorbing carbon dioxide (CO2) from the atmosphere in the process.

It means when biomass is combusted as a source of energy – for example for heat or electricity production – the CO2 released is offset by the amount of CO2 it absorbed from the atmosphere while it was growing.

Fast facts

  • In 2019 biomass accounted for 6% of Great Britain’s electricity generation, more than 1/6 of the total generation of all renewable sources
  • There is about 550 gigatonnes of biomass carbon on Earth in total. Humans make up around 1/10,000th of that mass.
  • Modern biomass was first developed as an alternative for oil after its price spiked as a result of the 1973 Yom Kippur War
  • The International Energy Agency (IEA) estimates bioenergy accounts for roughly 1/10th of the world’s total energy supply

Biomass is a renewable, sustainable form of energy used around the world.

How long has biomass been used as a source of energy?

Biomass has been used as a source of energy for as long as humans have been creating fire. Early humans using wood, plants or animal dung to make fire were all creating biomass energy.

Today biomass in the form of wood and wood products remains a widely used energy source for many countries around the world – both for domestic consumption and at grid scale through power stations, where it’s often used to replace fossil fuels with much higher lifecycle carbon emissions.

Drax Power Station has been using compressed wood pellets (a form of biomass) since 2003, when it began research and development work co-firing it with coal. It fully converted its first full generating unit to run only on compressed wood pellets in 2013, lowering the carbon footprint of the electricity it produced by more than 80% across the renewable fuel’s lifecycle. Today the power station runs mostly on sustainable biomass.

Go deeper

Read next: What is reforestation and afforestation?

How sustainable biomass crosses the Atlantic to power the nation

21 June 2017

Sustainable bioenergy

In the UK, we’re so accustomed to using electricity we rarely think of the journey it takes from power station to plug.

In fact, electricity must travel across a network of cables, wires and substations before it makes it from the power stations generating it to the homes and businesses using it. At Drax Power Station, which supplies 16% of Great Britain’s renewable power, there’s another journey that takes place even before the electricity leaves the power station.

This journey – the journey of more than half of the compressed wood pellet fuel Drax uses to generate electricity – has its origins in the expanse of forestland in the southern USA.

From forest to fuel

The journey starts in the huge, working forests of the southern states of the USA where low value wood – such as the thinnings cleared as part of a forests’ growing cycle – is collected in a responsible and sustainable way to make high density wood pellets, which Drax Power Station uses to produce more than 60% of its electricity.

Drax Group’s own pellet manufacturer, Drax Biomass, produces around 15% of the power station’s renewable fuel. After pelletisation locally at its Amite and Morehouse facilities, located in Louisiana and Mississippi respectively, the biomass is transported to Drax Transit at the Port of Greater Baton Rouge, on the Mississippi River. From Morehouse, trains made up of closed-top grain cars, each capable of carrying 120 tonnes, transport the pellets 221 miles to Baton Rouge. At Amite, just 60 miles from Baton Rouge, fuel-efficient trucks carry 25-tonne loads between plant and port.

Once at the port, the truck and train cargoes are unloaded into one of two biomass storage domes – each holding 40,000 tonnes of biomass – before being loaded into the ships for their transatlantic journey.

A boat arrives at Peel Ports in Liverpool

From port to port

Drax uses a range of ships to carry the pellets on their 8,000-mile journey to the UK, ranging from big ‘Coastal’ ships, capable of hauling 20,000 tonnes, to truly massive Panamax ships, more than a quarter of a kilometre in length and capable of carrying up to 80,000 tonnes.

The ships leave the port and spend 24 hours travelling the 200 miles down the Mississippi River into the Gulf of Mexico, around Florida, and into the Atlantic. From here, it’s a 19-day voyage to reach ports in the UK. To put that into perspective, it took Columbus more than two months to make his first trip across the Atlantic.

The ships pull into ports in Tyne, Hull, Immingham and Liverpool, where they are unloaded. At the bespoke biomass port facility at Peel Ports in Liverpool an Archimedean screw removes the pellets from the ship’s holds and transports them onto a conveyer belt, which loads them onto trains. These four ports can process up to 12 million tonnes of biomass every year, combined.

From port to power station

Like the stateside journey, Drax uses trains to carry its cargo from port to power plant. The difference on the UK side, however, is that the UK trains were designed specifically to carry biomass wood pellets. Clever design and engineering was used to maximise the space inside each carriage and ensure the trains carry large loads despite UK rail restrictions.

These trains carry the pellets across the country (and even over the Pennines for trains coming from Liverpool) to Drax Power Station in Selby, North Yorkshire. Roughly 14 trains arrive at the plant every day and collectively unload about 20,000 tonnes of pellets every day, from Monday to Saturday. A system of conveyor belts carry these pellets to one of Drax’s four giant biomass storage domes, each capable of housing about 80,000 tonnes of pellets.

Then, when needed, the conveyor system takes the pellets on their final journey: into the furnace. The pellets are combusted, which boils water to create steam, which turns a turbine connected to a generator, which then feeds electricity to the national grid. The electricity travels across miles of cables, and wires, through substations and transformers, and finally into your power socket.

An engineer looking into a Drax furnace

Long journey, low emissions

Despite the number of miles travelled, the journey of biomass is tracked and managed to ensure the Drax Power Station supply chain is as low-carbon as possible. The result is that, even with all supply chain emissions considered, the power generated has a carbon emissions profile that is more than 80% lower than coal.

It might be one of the most impressive supply chains involved in powering this island – but it’s not the only one to travel thousands of miles. The journey of biomass to England joins liquefied natural gas (LNG) shipped from the Middle East, coal from Colombia and solar panels manufactured in China – imports that ensure we have readily available access to power on our shores.

How many homes can we power with renewables?

25 May 2017

Power generation
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.

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.