Application of Multi-Criteria Decision Analysis (MCDA) for assessing the location of energy options: A literature review on the use of GIS-MCDA to inform the Master Plan

Abstract

BACKGROUND Information gathering about likely environmental and social impacts can play a major role in assuaging public concerns about the location of energy infrastructure, particularly when such data is used to enlighten developers about the optimal location of onsite infrastructure (Kazak et al., 2017; Sliz-Szkliniarz et al., 2019). As such a determination depends on many factors, the use of Multi-Criteria Decision Analysis (MCDA) has become increasingly popular in energy planning (Kazak et al., 2017). MCDA constitutes a type of Multi-Criteria Decision-Making (MCDM) support system, which can model social, economic and environmental factors, helping to provide a broad perspective on the overall merits of energy projects and diminishing the risk that interests specific to one or two social groups could carry overwhelming weight in decision-making (Harper et al., 2019; McKenna et al., 2022). A broad variety of criteria can be incorporated into MCDA methods for comparing the characteristics of energy projects, including but not limited to land uses, distances to ports, urban areas and distribution and transmission systems, wind speed, slope, air density, and ecological impacts (Tahri, et al., 2015; Villacreses et al., 2017). The quality of environmental information provided to inform MCDAs is a significant issue. In recent years, an increasing number of studies have utilised Geographic Information System (GIS) mapping in tandem with MCDA to enrich the data pool available to decision-makers. The aim of GIS mapping is to store, retrieve, manipulate, analyse and map geographical data (Church, 2002). The application range of GIS mapping is considerable, including but not limited to the mapping of landslide hazards (Carrara et al., 1995), health impacts (Brewer, 2006), ecosystem services (Troy and Wilson, 2006), place values (Brown et al., 2020), mineral prospectivity (Zuo et al., 2021), and solar radiation (Choi et al., 2019). MCDA operates via several approaches, which are commonly divided into two categories (i) multi-objective decision-making (MODM), and (ii) multi-attribute decision-making (MADM) (Ho, 2008; Pohekar and Ramachandran, 2004). MODM is a systematic process that aims to identify conflicts and trade-offs, reconciling these in a transparent manner through compromise and incorporating indicators of the strength of various preferences for specific objectives (Roijers, 2017). MADM involves the undertaking of preference decisions (including evaluation, prioritisation, and selection) concerning the available project alternatives that are typically characterized by multiple, conflicting attributes (Xu, 2015). The Analytic Hierarchy Process (AHP) has become one of the most applied approaches within MCDA. It compares multiple alternatives, each with several criteria to help identify the best option via pairwise comparisons (Vaidya and Kumar, 2006). This contrasts with approaches that utilise numerical values directly. OBJECTIVES AND METHODS Despite the increasing deployment of GIS approaches to inform MCDA in the context of various energy projects, the literature is scattered and, thus far, devoid of a review and synthesis of the main analytical approaches. Scrutinising the literature will help to identify the criteria in MCDA that are currently being informed by GIS mapping and the different types of MCDA platforms that are being used by decision-makers specific to energy projects. This information will be particularly useful for decision-makers who are considering the breadth of criteria that could make use of GIS-based information within MCDA, especially when such platforms are already applied and continuing to evolve. This is the case with respect to Iceland’s Master Plan for Nature Protection and Energy Utilisation (hereafter referred to simply as the ‘Master Plan’), which is a complex decision-support tool with a national scope and based on MCDA principles. It endeavours to reconcile the frequently competing interests of nature conservation and energy utilisation during the earliest planning stages. First commenced in 1999, the Master Plan became enshrined in Icelandic law in 2013 and is shortly entering its fifth evaluative phase. The first two evaluative phases of the Master Plan only evaluated the merits of potential geothermal and hydropower projects in Iceland, however, the third phase also encompassed wind farms. All energy projects subject to the Master Plan’s assessment are evaluated following consideration of multiple different interests, many of which are allocated weightings in the assessment process. This leads to an eventual ranking and the classification of all power plant options into one of three categories: utilisation, on hold, or protection. This report conducts a Systematic Literature Review (SLR) to fulfil its objectives. A combination of the Search, Appraisal, Synthesis and Analysis (SALSA), together with the snowballing method, is used in this SLR. These methods have been widely adopted in SLRs in a broad variety of decision-making contexts, including in Arctic ecosystem services (Malinauskaite et al., 2019), MCDA studies on geothermal power projects (Cook et al., 2019), sustainable energy development (Gunnarsdóttir et al., 2020), and the systemic risk issues pertaining to the COVID-19 pandemic (Cook and Jóhannsdóttir, 2021). STRUCTURE This report commences in Section 2, where further background material is provided concerning how MCDA studies are typically structured and operate in a renewable energy project context. Section 3 articulates the history of the Master Plan in Iceland and its structure, including its overarching Steering Committee and four Working Groups, is set out. The remit of each Working Group is described, together with the main criteria under evaluation. Section 4 outlines the SALSA method used to conduct the systematic literature review and provides the main results specific to each of the energy generating technologies under study – geothermal power, hydropower, and onshore wind. Section 5 discusses the relevance of the outcomes for the Master Plan, and the main practical and decision-making implications of the GIS-MCDA studies reported in the examined literature. Section 6 provides a brief conclusion and outlines potential areas for future research.