Life Cycle Assessment of Renewable Electricity Technologies: equimarginal incremental cost determination of ex-ante targets
: (Alternative Format Thesis)

  • Vahakn Kabakian

Student thesis: Doctoral ThesisPhD


Global concern of climate change has been growing in the past years leading to an accelerated deployment of renewable electricity technologies or plans for deployment thereof, in the form of national renewable electricity targets. Often, national renewable electricity targets are defined using cost-effectiveness analysis, in an effort to determine the cheapest pathway in reaching such targets. The cost-effectiveness analysis however, and as its name indicates, ignores the environmental burden of these technologies, unless monetization of the environmental externalities is conducted. While this allows to provide input into the cost-effectiveness analysis, and therefore allows the integration of environmental costs (or benefits) in the aforementioned analysis, environmental valuations are not universally applicable. This is due to the nature of the available methods (e.g., stated preference method), as the welfare of the society where such values are being generated impacts the results, limiting their geographical relevance. In addition, results of these monetization can vary as much as a factor of 10 in magnitude. In addition, and specifically in developing countries, decision-makers (including developers, appraisers and policymakers) prefer to determine the benefits (or the costs) in monetary terms based on financial indicators, as compared to the indicators applied in environmental valuation (where environmental indicators are used as a basis for monetization).

In parallel, renewable electricity technologies do pose certain environmental challenges, which need to be taken into account when such national targets are being set. Life cycle impact assessment can be used as a tool to evaluate the environmental merits of renewable electricity technologies. Most life cycle impact assessment methods do not “translate” these impacts into monetary values yet can provide additional input to multicriteria analysis. The impact assessment methods which do provide monetization of the environmental burden are faced with the limitations of monetization outlined above.

To address the above, this thesis applies a three-step approach (defined as objectives). First, it develops life cycle impact assessments of renewable electricity technologies (including electricity system and cement production) within the context of the case study. This is needed since life cycle assessment results lack universality in terms of spatial representation of assessments of renewable electricity technologies). This is due to the fact that local parameters (e.g., wind availability and speed, solar irradiation, cement manufacturing, etc.) have a larger bearing on results, which stipulates the need to generate results based on context-specific parameters (Objective 1 – chapters 2, 3, 4, and 5).

Second, the thesis applies the results obtained from the life cycle impact assessments in various multi-criteria analysis methods as well as applies monetization. This allows to demonstrate the applicability of life cycle assessment results in various existing multi-criteria analysis tools yet provides an opportunity to highlight the shortfalls of monetizing externalities (Objective 2 – chapters 3, 4, and 5).

Third, and as a final step, an environmental effectiveness framework is proposed, as alternative approach in generating additional cost incurred of environmental considerations of renewable electricity technologies without the need in monetary valuation of externalities. This is done by first applying the equimarginal principle in determining the cost-effectiveness analysis of the renewable electricity technologies in Lebanon (allowing the generation of the least cost option, and therefore the fleet of renewable electricity technologies needed to meet the ex-ante target and its respective financial cost). Following this, a ranking of these same technologies, based on their environmental performance (from least to most damaging, based on conducted the life cycle impact assessment analysis), and their respective financial costs are used to determine the incremental costs in meeting the ex-ante target, thus avoiding the need of monetary valuation method to internalize the environmental cost (Objective 3 – chapter 6).

Impact of the PhD:
This PhD has had several contributions towards generating life cycle inventory data and results (chapters 2, 3, 4, and 5), in addition to demonstrating the use of life cycle assessment as a tool for decision-making in various multi-criteria methods (chapters 3, 4 and 5). From a broader life cycle assessment perspective, the current PhD populates the literature with results from a region where life cycle assessment studies are absent, within the framework of life cycle assessment of renewable electricity technologies (photovoltaic, concentrated solar power, wind, hydropower), and their respective performance within the local geographical context as well as cement production. Therefore, this PhD contributes to the body of knowledge on the environmental assessment of a country/region electricity mix which could be used in various databases. This is important to overcome the limitation of using generalized meta-data in life cycle assessment (Laurent et al., 2014) since life cycle assessment results are strongly dependent on the context and local specificities which challenges the usefulness and relevance of such generalizations (i.e., reliance on global datasets) (Ripa et al., 2017).

Furthermore, the PhD develops an environmental effectiveness framework based on life cycle assessment results and in combinational of the equimarginality principle, in proposing an alternative approach to avoid internalisation of externalities yet giving due considerations to the environmental merits (and impacts) of renewable electricity technologies (chapter 6). The proposed new approach relies on financial costing. This is done by conducting a cost-effectiveness analysis (least cost – equimarginality principle) of renewable electricity technologies based on the available renewable electricity generation potential; it then introduces the life cycle assessment of renewable electricity technologies and generates a “least-damaging” ranking, thus creating an environmental effectiveness analysis. Finally, the costs (obtained in the cost-effectiveness analysis) are then combined with the results obtained in the life cycle assessment, in order to generate costing of the best environmental performing mix of renewable electricity technologies. This creates what can be considered as an environmental effectiveness analysis framework, which allows the deduction of the financial incremental cost of environmental considerations without the need to internalize externalities.

This thesis resulted in a number of peer reviewed publications: two papers published academic journal articles (chapters 2 and 3), one published as a book chapter (chapter 5). Chapter 4 has been submitted for publication and is currently under review.
Date of Award26 Jul 2023
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorMarcelle McManus (Supervisor)

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