Bioenergy

[1] The biomass that is used as input materials consists of recently living (but now dead) organisms, mainly plants.

[3] Bioenergy can help with climate change mitigation but in some cases the required biomass production can increase greenhouse gas emissions or lead to local biodiversity loss.

[5]: 637  Most of the recommended pathways to limit global warming include substantial contributions from bioenergy in 2050 (average at 200 EJ).

[6]: B 7.4 The IPCC Sixth Assessment Report defines bioenergy as "energy derived from any form of biomass or its metabolic by-products".

The term traditional biomass for bioenergy means "the combustion of wood, charcoal, agricultural residues and/or animal dung for cooking or heating in open fires or in inefficient stoves as is common in low-income countries".

Bioethanol is made by fermentation, mostly from carbohydrates produced in sugar or starch crops such as corn, sugarcane, or sweet sorghum.

Biodiesel is produced from the oils in for instance rapeseed or sugar beets and is the most common biofuel in Europe.

[15] Lifecycle surface power density includes land used by all supporting infrastructure, manufacturing, mining/harvesting and decommissioning.

However, BECCS can also result in net positive emissions depending on how the biomass material is grown, harvested, and transported.

Deployment of BECCS at scales described in some climate change mitigation pathways would require converting large amounts of cropland.

[28] However, the establishment and cultivation of bioenergy crops can displace natural ecosystems, degrade soils, and consume water resources and synthetic fertilisers.

[29][30] Approximately one-third of all wood used for traditional heating and cooking in tropical areas is harvested unsustainably.

In some cases, the impacts of land-use change, cultivation, and processing can result in higher overall carbon emissions for bioenergy compared to using fossil fuels.

The low surface power density has the effect that much larger land areas are needed in order to produce the same amount of energy, compared to for instance fossil fuels.

Biomass plant in Scotland.
Wood chips in a storage hopper, in the middle an agitator to transport the material with a screw conveyor to the boiler
Eucalyptus plantation in India.
Example of BECCS: Diagram of bioenergy power plant with carbon capture and storage . [ 18 ]
Alternative system boundaries for assessing climate effects of forest-based bioenergy. Option 1 (black) considers only the stack emissions; Option 2 (green) considers only the forest carbon stock; Option 3 (blue) considers the bioenergy supply chain; Option 4 (red) covers the whole bioeconomy, including wood products in addition to biomass. [ 26 ]