York, 16th November 2017 - Successful
collaboration between North Energy, Forest Research and NNFCC Ltd has seen
completion of the “Carbon Life Cycle Assessment Evidence Analysis” project for
the Energy Technologies Institute.
Starting in July 2016, this project has evaluated the total greenhouse
gas emissions associated with potential relevant future bioenergy value chains
for the United Kingdom.
Careful
definition of the clear and detailed goal and scope of this work established
the need to apply consequential life cycle assessment. Following appropriate screening of 147
potentially-relevant bioenergy life cycle assessment studies, 49 full critical
reviews were conducted. This revealed a lack
of transparency and inadequate coverage which demonstrated the basic
limitations of any meta-analysis for the valid comparison of LCA results.
Instead,
suitable workbooks were developed for calculating greenhouse gas emissions
consistently and comprehensively for 510 possible bioenergy value chains
consisting of the production of heat and/or electricity, hydrogen and ethanol
from pellets derived from conventional forests, short rotation forests, short
rotation coppice, miscanthus and straw.
These workbooks were supported by a compendium of 7,518 individual
values of data compiled from 176 original sources. They were used to generate 2,385 comparable results,
in the form of estimated total greenhouse gas emissions, all calculated using
consistent methodology and emissions factors. They were then used to examine the effects of
variability and to provide 19,462 results for analysing sensitivities,
including modelling uncertainties.
Important
knowledge gaps, consisting of choices of forest management scenarios and
practices, wood products, counterfactuals, and waste management; emissions from
biomass storage; indirect land use change; and non-carbon dioxide emissions
from biomass feedstock combustion and conversion, were identified and practical
means for addressing them were prescribed.