Decision Making methods for Sustainable Energy

Contemporary energy issues urge decision makers to plan and select among energy alternatives. Typical for these issues is their complexity with divergent consequences on different dimensions. In order to choose the best solution, decision-makers use methodological tools. An literature review of these tools shows that analysis that take into account multiple criteria are popular. Also subjectivity appears an important factor weighing these criteria. The results of their research elicits which criteria are seen as important by decision-makers.

The authors looked at the multi-criteria decision analysis (MCDA) that are undertaken while deciding between energy alternatives. Besides a focus on the goal of sustainability, these criteria reflect the technical (dis)advantages of these energy alternatives and their socio-economic and environmental implications. In their literature review they researchers looks at: (a) which criteria were selected; (b) what weighting methods were use, and; (c) with with methods the results were aggregated. The sample of reports under study applied MDCA on different energy issues diverging from planning to selection, resource allocation exploitation, transportation, etc. Notwithstanding, the focus was primarily aimed at the energy supply systems which ranged from combined (cooling) heating and power (CCHP) systems to renewable energy systems.
Criteria Selection
The criteria that were selected could be classified in four categories (1) Technical; (2) Economic; (3) Environmental, and; (4) Social. The ten most popular criteria were Technical (efficiency, safety, and reliability), Economical (investment costs, operation and maintenance cost, fuel costs), Environmental (CO2- emission, NOx Emission, Land Use) and Social (Job creation).

Criteria Weighting
Also the researchers looks at the way the criteria where weighted. The most popular methods were of subjective nature. With the AHP, Pair-wise comparison an ‘priority given to one indicator with others bing the same. The objective method (or a combination) was less popular than treating all criteria as equally important.The most popular way to subjectively selected the weights is by pair-wise comparison and AHP (which builds on the same principle). Another popular method is by giving one indicator more weight to protrude the outcome. Analysis of the results is done with different methods from elementary methods, to synthesize uniqueness of the criteria, and outranking methods. For example the elementary ‘weighted sum’ is most commonly used  in sustainable energy systems. Synthesizing happens commonly with the AHP method or the Fuzzy method. The latter focuses on fuzzy rather than crisp values, outputting outcomes which are more understandable for the decision-maker. Also outranking is frequently used when alternatives cannot be compared and require to be expressed in binary relations.

Aggregating results
The final aggregation may be based on the ranking order of the alternatives. But in some cases multiple MCDA methods are used. If this is the case, voting is a popular method.


Summary of ‘Review on Multi-criteria decision analysis aid in sustainable energy decision-making’, by Jiang-Jiang Wang, You-Yin Jing, Chun-Fa Zhang, Jun-Hong Zhao,
As published in Renewable and Sustainable Energy Reviews 13 (2009) 2263-2278