A Roadmap to Sustainability Evaluation: a System Approach from Evaluation Theories

Sustainability evaluation has been widely applied as a tool to manage the relationship between humans and the Earth to avoid human activities that jeopardise the survival of all lives and subsequent implementations have been improving sustainability within certain times and regions. However, consequently, many measures have proved unsustainable outside suitable spatio-temporal scales. While abundant research attempted this issue by developing sustainability frameworks that apply wider systems as evaluation subjects or designing compound indexes, limited work recognise the evaluation nature and analyse from the evaluation theories perspective where the issue could be the consequences of having implicit elements in sustainability evaluation.

The issue is attempted following three key research objectives. First, determine the characterisation of evaluation elements by embedding sustainability. Critical literature on evaluation theories, sustainability, and sustainable development (SD) from nearly all fields of study are collected, screened, and analysed. A group of fundamental evaluation elements are summarised to be applicable for this thesis, as a reflection of evaluation theory basis. Proper evaluation should explicitly characterise this group of evaluation elements by decision makers (DMs) and evaluators. Sustainability objectives, where certain criteria should be defined specifying the sustainable state, would influence the characterisation of all evaluation elements. Thus, we state, in practice, that sustainability evaluation is done for a group of necessary conditions towards planet sustainability during which values of key stakeholders including human and non-human lives require demonstration.

Second, construct a framework that could develop explicit sustainability evaluation elements with applicable metrics and measurements. Critical literature of sustainability evaluation and key heuristic studies are reviewed and a systemic review of 118 sustainability evaluation empirical studies in the energy sector is conducted. It is confirmed the causes of implicitly unsustainable measures from the evaluation perspective are that sustainability evaluations often implicitly place human values in centre but hold shifting stakeholder stances between human-central or universal values, and many evaluation elements are implicit, especially the evaluation objectives and subject when they are not mutually suitable. Noticing that based on stakeholder connections and criteria of sustainability the evaluation objectives and subject would be explicitly developed, an evaluation framework for sustainability enabling developing of explicit and suitable evaluation elements is constructed, forming a roadmap to sustainability evaluation. The roadmap demonstrates a process of explicitly forming an apposite system for sustainability evaluation objectives that is used as the evaluation subject. The sustainability evaluation framework concludes with metrics of material and energy, structure, and value (MSV). Evaluation results are produced for the apposite system and implementations for the initial system. For cross-system evaluation, a group of suitable, EEV, measurements are proposed. Material metric could be treated as classifying renewable or non-renewable materials. Energy metric could be measured by emergy that traces system energy hierarchy with unified unit. Structure metric could be measured by Shannon entropy. The value measurement could be compensated by human pricing while considering the survival of weak stakeholders.

Lastly, the applicability of the roadmap is tested based on the electricity systems of 28 European countries, including the production system and consumption structures. Suggested by the country sustainability objectives of carbon neutrality and targetting energy security, a CO2 sustainable electricity production system targetted for 2005 country sustainability evaluation objectives including 10 electricity production technology subsystems is constructed as a sustainable reference system. Country peer ranking is calculated by individual indexes of energy, entropy, and electricity prices, and compound scores by data envelopment analysis (DEA). It is revealed that the evaluation framework, especially following the proposed protocol, would require mass high-quality data and information for linkages of subsystems, providing directions to refine the framework and evaluation results.