Suchergebnisse

Biomass sustainability criteria were introduced in the UK following the EU Renewable Energy Directive. Criteria are now applicable to solid biomass and biogas, however because it is not mandatory criteria can be adapted by member states with the risk of different interpretation. Operators are required to report greenhouse gas (GHG) emissions for every MJ of energy produced. This paper provides a rigorous analysis of the current GHG emissions accounting methodology for biogas facilities to assess expected compliance for producers. This research uses data from operating CHP and biomethane facilities to calculate GHG emissions using the existing methodology and Government calculator. Results show that whilst many biogas facilities will meet GHG thresholds, as presently defined by Government, several operators may not comply due to methodological uncertainties and chosen operating practices. Several GHG accounting issues are identified which need to be addressed so the biogas industry achieves its reporting obligations and is represented objectively with other bioenergy technologies. Significant methodological issues are highlighted; including consignment definition, mass balance allocation, measurement of fugitive methane emissions, accounting for digestate co-products, fossil fuel comparators, and other accounting problems. Recommendations are made to help address the GHG accounting issues for policy makers and the biogas industry.

This paper takes an integrated analysis approach to explore the options available for a UK homeowner to reduce their domestic emissions to the level advised by the UK governments Committee on Climate Change of 20% of those associated with a typical house in 1990. It uses proven thermal models of a typical house and low carbon heating systems to estimate the emissions associated with domestic heating and electricity consumption from a number of combinations of low carbon micro generation technologies. The amount of additional low carbon electricity needed to offset these emissions to the desired level was then calculated. The capacity of photo voltaic panels needed to generate it was then estimated. This has been done over a range of different grid carbon intensities and the resulting configurations have been subjected to energy analysis and financial appraisal. An environmental life cycle assessment was also undertaken to see if there were any unacceptable environmental consequences of an owner adopting any of the options. The research shows that in all cases operational GHG target can be met, but that emissions associated with the production of the systems is variable, meaning that with current technology a 25% house is more likely. It has also been shown that given current subsidies the installation of some of the proposed systems should be financially attractive to the home owner. ?