This approach is employed to evaluate selected individual and multiple distributed energy resources (DERs) in the UK context on a life-cycle ("full fuel cycle") basis. Thermodynamic, environmental and economic appraisal techniques are applied.

The thermodynamic analysis accounts for the quantity of energy consumed and its inherent quality (encapsulated in a property known as "exergy"). DER-specific LCA methods encompass various pollutant emissions (with a focus on carbon) and their eco-toxicology. This work can also make use of a peer-reviewed inventory of embodied carbon to yield estimates of carbon footprints on a short timescale. These two analyses are interrelated in that life-cycle energy analysis (EA) was one of the precursors for environmental life-cycle assessment (LCA), and is typically performed in parallel with environmental appraisal in most LCA software packages. Both EA and LCA may be employed to estimate impact inventories that can be coupled with environmental cost-benefit analysis (CBA) to produce environmental costs (the ‘external’ costs imposed on the wider economy) for particular energy systems. More limited financial costs and benefits are also being determined in the manner employed for project investment appraisal, yielding the financial metrics applicable to DER manufacturers or to householders.

LCA provides an evaluation of emissions applicable within a global context. However, local impacts are often important. Likewise, there are some environmental burdens that are difficult to quantify and require a qualitative approach. It is therefore important to supplement the integrated appraisal methods described above with a wider portfolio of qualitative tools, including risk assessment and stakeholder mapping and engagement. This constitutes the elements of a “sustainability assessment framework”.  

For further information please contact the Sustainable Energy Research Team (SERT) at the Dept. Mechanical Engineering, University of Bath http://www.bath.ac.uk/mech-eng/sert/