Bioenergy is gas or electricity that comes from renewable sources, such as plant matter or animal waste.
This is known as biomass.
Biomass contains energy stored from the sun. This energy is absorbed during the photosynthesis process.
When biomass is burned, its chemical energy is released as heat.
Biomass is often burned on a local scale to heat homes and to provide heat for cooking (mainly in less developed countries), and as such is an important part of many peoples’ livelihoods.
However, bioenergy is more often spoken about in terms of the large-scale and intensive harvesting and burning of wood from forests in the US, Canada, and Europe. Today, most biomass which is burnt for energy on this scale comes from trees, and more worryingly, from forests.
What is the link between bioenergy and deforestation?
To reduce their carbon emissions, governments are shifting from burning coal for energy, to burning biomass - mostly in the form of wood pellets.
To feed this rising demand for biomass, forests are cleared for wood. This is pulverised into dried pellets, which are then transported and burned in power stations to generate heat and electricity in homes and businesses.
As a result, protected, biodiversed forests have been indiscriminately razed, causing damage to people and wildlife.
Does Europe implement bioenergy?
Yes. A staggering 22 million tonnes of pellets, many of which are imported from the US, are burned in the European Union every year.
This is a direct result of the EU’s Renewable Energy Directive, which first came into force in 2009, and is seen as a central means of helping the EU reach its goal of cutting its carbon emissions by 40 per cent by 2030.
The EU is committed to sourcing 32 per cent of its energy from renewable sources by this year.
Almost 60 per cent of renewable energy consumed in the EU is from biomass, according to the European Commission.
Is bioenergy a renewable source or carbon neutral?
Proponents of burning wood for energy argue that because harvested trees can be replaced with new trees, it is a renewable source of energy.
When wood is burned for energy, it actually emits more carbon on a per-unit-of-energy basis than burning coal.
Burning wood immediately releases carbon dioxide, increasing the amount of CO2 in the atmosphere. When a new, young tree is planted, there is a lag time of decades to centuries before that same amount of CO2 is reabsorbed by new growth.
Intensive forestry might also remove roots from the soil, and remove left-over branches from the forest, rather than allowing stored carbon to remain in the forest in the form of soil and organic matter. Therefore, chopping down trees and burning them for bioenergy reduces the natural carbon sink and increases the world’s “carbon debt”.
This was pointed out in 2018 by 800 scientists, who warned that deliberately harvesting wood for energy “will increase carbon in the atmosphere and warming for decades to centuries – even when wood replaces coal, oil or natural gas.”
Second, when wood is burned for energy, it actually emits more carbon on a per-unit-of-energy basis than burning coal.