Energy aspects in LCA of forest products

Abstract

This paper outlines guidelines for the treatment of energy in LCAs of forest products. The paper is a result of the Cost Action E 9 ‘Life cycle assessment of forestry and forest products’ and reflects the experience of Cost E9 delegates, contributing to Working Group ‘End of life — recycling, disposal and energy generation’. After overviewing different aspects of energy in LCA of forest products, the most important aspects are identified: 1) energy and carbon balance, 2) energy generation, 3) energy substitution and 4) comparison with other waste management options. For these aspects, guidelines are developed and examples are given to demonstrate the practical application of recommended guidelines. Beside the proper treatment of the above mentioned aspects, the following conclusions for the LCA practitioners are given: 1) Draw attention to losses of potential energy in carbon flows. 2) Compared to heating value of biomass the auxiliary energy need is low (<10%). 3) The substitution rate (bioenergy for fossil fuel) might be lower than 100%, depending on technical systems available. 4) A high substitution rate might be an optimisation criterion for LCA. 5) A sensitivity analysis of different substitution criteria should be made. 6) Compare energy generation to other waste management options. 7) Use of bioenergy might be ‘CO2-neutral’, but not ‘CO2-free’. 8) Most important benefit of bioenergy is greenhouse gas reduction by substituting fossil energy.