Biomass

DEFINITION: Organic matter, such as timber and crops, that can be converted to fuel and is generally regarded as a renewable fuel source. Biomass is sustainable and generally carbon-neutral because the carbon released in the combustion process is offset by the carbon trapped in the organic matter by photosynthesis during its growth. In biomass power plants or boilers, wood waste or other waste is burned to produce stream that runs a turbine to make electricity.

Biomass is considered by many companies and governments to be a renewable and sustainable source of energy, but its use is somewhat dividing the sustainability sector.

Biomass as a sustainable energy source

Biomass has long divided the sustainability sector, with one camp stating it is a renewable source of energy that prevents waste ending up in landfill, while its opponents suggest it is little better than fossil fuel use.

Proponents of biomass say it is a renewable source of energy, because:

• Waste residues will always exist – for instance scrap wood, mill residuals, forest resources – and to burn these prevents them ending up in landfill sites.
• Managed forests will always have more trees, and we will always grow crops, offering an endless source of residual biological matter for biomass.

However, opponents of biomass as a sustainable energy source point out that:

• CO2 is released into the atmosphere when wood or gas biomass is burnt in a power station, just as it is with fossil fuels.
• Biomass contributes to climate change, so it is argued that should not be included in sustainability targets, and renewable energy companies and governments should focus on “true” renewables like solar and wind.

Types of biomass

Wood and agricultural products

Most biomass used today is plant-based. Wood - logs, chips, bark, and sawdust - accounts for about 44% of biomass energy, while other biomass sources include agricultural waste products like fruit stones and corncobs. Currently, a great deal of the electricity and heat generated is used onsite by the industries creating the waste.

Solid biomass for use in power plants is sometimes dried and pelletised for easier transport and cleaner burning, and sometimes co-fired with other fuels. Alternatively, they may be used for heat or combined heat and power (CHP) production.


Solid waste (waste-to-energy)

Burning our rubbish turns waste into a usable form of energy, with 2,000 pounds of average household refuse containing about as much heat energy as 500 pounds of coal.
However not all refuse is biomass, with perhaps half of its energy content coming from plastics. In current refuse disposal systems, separating this plastic would be extremely costly. This, coupled with more general concerns over fuel-based power generators, means the use of solid waste causes a great deal of controversy in the sustainability sector.

Gas biomass (methane)

Methane can be collected from landfill sites, plant matter (silage), or animal manure. Gas biomass is increasingly being produced in specially designed airtight digesters, and the gas enriched to provide a cleaner burn to produce electricity, or for cooking and lighting.
There is also increasing usage of specially-grown energy crops such as elephant grass, which are often mixed with other waste products with a low energy content such as some manures and spoiled grain to boost gas yields.

Ethanol gasoline and biodiesel

As all brewers, wine makers and distillers know, virtually any organic materials containing cellulose, starch, or sugar can be fermented, producing ethanol. Most of the ethanol produced in the US comes from corn, and nearly all the gasoline sold contains 10%-15% ethanol, while fuel containing 85% ethanol is available for adapted vehicles.
Biodiesel is mostly made from soybean oil, and mixes of up to 20% can be used in unmodified vehicles. Biodiesel has become especially popular in South America in countries looking to reduce their dependence on oil-based gasoline.

Co-firing coal power plants with biomass

One of the biomass uses currently attracting a lot of interest is the use of biomass fuel – usually dry wood pellets – in co-firing coal power stations. This offers two key benefits in reducing carbon emissions while lowering reliance on fossil fuels.
However, experts are divided on the net effect of co-firing. One study has suggested that if 5% of coal burned were replaced with biomass pellets, it would reduce CO2 releases by 16%. Others say co-firing has the potential to make coal power stations carbon-neutral, but this would necessitate much greater ratio of biomass to coal.
A key concern of co-firing is that biomass does not have the same ‘heat content’ as coal, meaning it takes a lot more energy to operate the systems and to produce a viable fuel. Therefore, carbon emissions may actually be greater than from burning pure coal.
But co-firing is being developed in countries that traditionally have a high dependence on coal power. 

So, is biomass green?

The pros of biomass

Supporters of biomass as a sustainable energy source say it is carbon neutral, since it is generated from renewable organic waste that would otherwise be dumped in landfills, openly burned or left as fodder for forest fires.
New technologies such as pollution controls and combustion engineering have advanced so biomass emissions now generally produce less emissions than comparable fossil fuel use.
Unlike other renewable power sources – such as solar and wind – a biomass power plant can operate 24/7, at any time of the year. Combined with new advancements such as battery storage, supply management and demand response, biomass can offer a more consistent and reliable renewable stream of energy.

The cons

Environmental groups including Friends of the Earth challenge the biomass “carbon neutral” claim, indicating that when wood and crops are harvested and burnt, they emit CO2 into the atmosphere and create a “carbon debt”. This debt may be repaid by recapture of carbon from growth and regrowth of crops and forests, but it could take many decades for the emissions to be neutralised.

Wood biomass is also highly dependent on proper management of forest resources, and there is always a risk that burned virgin forests will be replaced by faster-growing trees or even crops (such as palm oil), reducing the carbon capture potential and irrevocably damaging ecosystems.
There are also other factors to consider in the biomass supply chain. All biomass fuels need to be acquired, prepared, and transported. Preparation and transportation can add costs to an otherwise negative value fuel of biomass or other wastes.

The biomass subsidy question

In the UK, the government has recently been attacked for subsidising biomass development, with experts suggesting that solar, wind and energy efficiency upgrades to buildings could be boosted by re-aiming the subsidy streams.
Government bodies are currently at odds over the labelling of biomass as carbon neutral. The European Environment Agency (EEA) says biomass is not always carbon neutral and must follow EU resource efficiency principles.
But there is no question that ‘true’ renewable sources like solar and wind will not be able to replace coal, oil and natural gas use, at least in the short- to medium-term. More research is needed, but biomass has a role to play in reducing dependency on fossil fuels.

Related items

More than 78% of the packaging on all Tesco-branded products is recyclable Image: Tesco

Tesco supports deposit return scheme for plastic packaging

Following Theresa May's declaration that all avoidable plastic waste will be eliminated in the next 25 years, UK supermarket retailer Tesco has announced its support for a "cost-effective" deposit return scheme on packaging.

edie Explains: The green office

The purpose of a green office programme is to enable a business to improve the efficiency of its everyday operations by taking practical steps to reduce office resource consumption and implement more sustainable practices that benefit both the organisation and its employees.

Towards a sustainable economy

CISL and its recently formed Rewiring the Economy Inquiry Group published its latest report ‘Towards a sustainable economy’, to identify new business approaches that can drive progress towards the SDGs.

To date, 868 tonnes of coffee has been collected through the initiative to be transformed into biomass pellets

In practice: Network Rail's closed-loop partnership to recycle waste coffee grounds

Striking a partnership with coffee waste collectors Bio-Bean enabled Network Rail to make steps in reducing waste at its station, and also got retailers and staff to boost coffee collection to be used for renewable power.

The Waterside campus will have 100% of its heating and hot water needs served by the new energy centre by using woodchip biomass and gas

In practice: University of Northampton's onsite biomass energy centre

A state-of-the-art new campus at the University of Northampton has embraced a renewable energy solution through a £6.5m energy centre which incorporates woodchip biomass boilers and a combined heat and power (CHP) system.

Drax has previously suggested that the biomass conversion of three of its power plant units will cut 12mtCO2e per year from the power station's operations

Drax eyes battery storage to accompany gas and biomass conversions

UK power station operator Drax plans to complement its ongoing biomass conversions with gas and battery storage options at two coal power units, although new research that wind and solar are a more cost-effective solution has reignited the debate over biomass use.

Stora Enso expects two-thirds of energy consumption at its mills to come from biomass derived from burning wood bark

In practice: Stora Enso's cost-effective move to champion cross laminated timber

A new multi-million-euro investment looks set to transform packaging firm Stora Enso into a renewable materials company and the largest global producer of a low environmental impact timber solution to replace steel and concrete in construction projects.

Onsite generation can help businesses save money on energy bills and even generate income by selling surplus energy back into the grid

edie publishes free business guide to onsite energy generation

Organisations and professionals with an interest in producing and consuming energy at a particular location away from the grid now have access to a free, comprehensive 'edie explains' guide which answers all of the key questions surrounding onsite generation.

edie explains: Onsite generation

This edie explains business guide, produced in association with E.ON, provides an in- depth summary of onsite generation, which allows businesses to make and use their own energy at a particular location, rather than buying that energy through the grid.

ETI argues that delivery of energy crops must be balanced with the demand for land use from other agricultural sectors

ETI: UK-grown biomass can support farmers and deliver carbon savings

Planting 1.4m hectares of non-food crops dedicated to the production of bioenergy can deliver "genuine" emissions savings and provide a degree of income security for UK farmers, according to new research from ETI.

The UK is the biggest importer of wood pellets in the European Union (EU), shipping in more than seven million tonnes from the US and Canada in 2015

UK's biomass ambition: Low-cost solution or forest full of loopholes?

A new report has outlined that using waste and biomass for gasification can help the UK meet its 2050 carbon targets at a lower cost to the economy, on the same day that research condemned a biomass standard used by Drax, E.ON and DONG as a "forest of loopholes".

Wind energy output peaked at 9.5GW on Wednesday 7 June

Windy weather brings new renewable energy record

Windy weather brought with it a new renewable record on Wednesday lunchtime as output from wind, solar, biomass and hydro peaked at 19.3GW - more than half of all demand.

While poultry litter biomass has received a boost across the country, using ground coffee waste for a similar purpose is expanding outside of London

Coffee grounds and poultry litter proving a viable biomass option in the UK

As innovative waste coffee recycling firm bio-beans expands its collection service across the University of Birmingham, the UK Government has revealed that Combined Heat and Power (CHP) plants using poultry litter will receive the highest tariffs under the Renewable Heat Incentive (RHI).

Energy Transitions Commission: Better energy, greater prosperity

The Energy Transitions Commission’s flagship report sets out achievable pathways to limit global warming to well below 2C while stimulating economic development and social progress.

The risks and rewards of brokers

As the non-domestic retail water market opens on April 1, brokers are anticipating a boom in business. edie sister title Utility Week has provided an in-depth guide to the utility broker market as it stands, and considers how it is likely to change after market opening.

SDGs mean business: How credible standards can help companies deliver the 2030 Agenda

This new report published by WWF and ISEAL indicates how businesses can contribute strongly to the 2030 Agenda for Sustainable Development and unlock new market opportunities by using credible voluntary sustainability standards to transform entire sectors and supply chains.

The UK is the biggest importer of wood pellets in the European Union (EU), shipping in more than seven million tonnes from the US and Canada in 2015

Biomass 'carbon neutrality' debate continues to divide opinion

Using biomass, specifically energy derived from burning wood, as a crux in the UK's effort to transition towards a low-carbon economy has come under scrutiny again, after the former secretary for energy and climate change and his ex-special advisor clashed over its use.

10 top tips to drive engagement with your CSR report

What are the key components required to produce a sustainability report which drives engagement on a range of CSR issues among key stakeholders? edie brings you the secrets to sustainability reporting success with this latest top-tips guide for businesses.

Warwickshire's Upton House is now fuelled by two wood-pellet boilers, saving £6,000 a year on energy bills and 55 tonnes of carbon emissions. Photo: National Trust

National Trust champions on-site solutions in renewables revolution

EXCLUSIVE: The National Trust is continuing its march towards self-sufficient energy generation, having produced 12% of its heat from on-site renewable energy sources in 2016 – four years ahead of Britain's national renewable heat targets.

First Mile's chief commercial officer Joe Allen (left) and Caffè Nero's commercial director Matt Spencer (right) are pleased by the success of the ongoing partnership

Caffé Nero reports coffee-waste-to-biofuel success, plans expansion

Italian-style coffee shop chain Caffé Nero is looking to extend an innovative coffee-to-biofuel recycling scheme beyond greater London after a successful partnership with recycling company First Mile and technology firm Bio-Bean.

Birmingham Town Hall. A series of workshops will provide Midlands businesses with specialist expertise about advanced thermal technologies and biological conversion processes

UK businesses to accelerate bioenergy opportunities through EU grant

A European Union (EU) funded project is set to support firms across the West Midlands to reap the economic and environmental benefits from bioenergy and thermal technologies.

Sustainability Leaders Awards 2017: meet the winners!

Welcome to the winners report for the 2017 Sustainability Leaders Awards. Organised by edie, these awards recognise excellence across the spectrum of sustainable business; from the best efficiency programmes through to product innovation, from stakeholder engagement and CSR initiatives to the people making it happen.