Introduction to Bioenergy

Biomass is all organic material, an example being plant matter. It is either:

• the direct product of photosynthesis (for example plant matter – leaves, stems, etc.) or
• the indirect product of photosynthesis (for example animal mass resulting from the consumption of plant matter).

'Biomass' shall mean the biodegradable fraction of products, waste and residues from agriculture (including vegetal and animal substances), forestry and related industries, as well as the biodegradable fraction of industrial and municipal waste.

EU Directive 2001/77/EC (RES-E) - promotion of electricity produced from renewable energy sources

Types of biomass that are used to provide bioenergy include:

• wastes streams, including residues from forestry and related industries
• recycled wood
• agricultural residues and agrifood effluents
• manures
• the organic fraction of municipal solid waste
• separated household waste and sewage sludge
• purpose grown energy crops including short rotation forestry, miscanthus grass, etc.

For more information download the SEAI Briefing Document on Biomass (.pdf, 150kb) or Biomass Factsheet (.pdf, 2082kb)

Biofuel is a term used for biomass which has been prepared/upgraded to provide bioenergy. Biofuel can be either:

• solid biofuel, e.g. wood pellets (see Wood energy) straw (www.videncenter.dk/uk/index.htm) publications - Straw for Energy Production - Technology - Environment - Economy
• liquid biofuel e.g. biodiesel, which can be used as a vehicle fuel (see Liquid biofuels).

Bioenergy, or energy from biomass, supports a wide range of national policy goals:

• Key energy goals including security and diversity of supply and the development of indigenous renewable energy sources
• Key environmental goals such as greenhouse gas emissions reduction* and waste management
• Key agricultural goals offering new opportunities for farmers in the context of CAP reform
• Key social goals such as employment generation in rural areas and enhancement of local economies

*Note 1:  The carbon dioxide (CO₂) emitted on combustion of biomass is taken up by new plant growth, resulting in zero net emissions of CO₂ – bioenergy is considered to be carbon neutral. However, it should be remembered that there are some net CO₂ emissions associated with bioenergywhen looked at on a life cycle basis – emissions from fossil fuels used in cultivation / harvesting / transport of the biomass. These are generallysmall compared to the CO₂ avoided by displacing fossil fuels with energy from biomass.