Abstracts

Compressed Air Energy Storage in Salt Caverns: Geomechanical Design Workflow, CAES Siting Study from a Geomechanics Perspective, and Deep Brine Disposal

by Jai Duhan




Institution: University of Waterloo
Department:
Year: 2018
Keywords: salt caverns; brine disposal; compressed air energy storage; geomechanical design workflow; multi-criteria analysis
Posted: 02/01/2018
Record ID: 2206529
Full text PDF: http://hdl.handle.net/10012/12925


Abstract

As agreed in the Paris Agreement, Canada is committed to combat climate change through reducing greenhouse gas (GHG) emissions and keeping the temperature rise well below 2 C above pre-industrial levels. One of the ways to achieve this goal is through replacing high GHG emitting electricity sources with renewables energy, such as wind and solar energy. However, due to their intermittent nature, wind and solar must be paired with energy storage to be a reliable source of electricity. Compressed air energy storage (CAES) in salt caverns is a well-demonstrated and effective grid-scale energy storage technology that can support large-scale integration of renewables. This thesis addresses on three major aspects of implementing CAES in Canada: I) geomechanical design workflow, II) CAES siting in salt caverns across Canada: a geomechanics perspective, and III) potential of deep brine disposal in southwestern Ontario. Part I of the thesis discusses the geomechanical design workflow for CAES in salt caverns. The workflow includes tasks and design decisions that are executed from a CAES projects pre-feasibility period to end of operation period. The major sections of the workflow include geology, data collection and mechanical earth model, constitutive model: creep, geomechanical issues and cavern design decisions, and monitoring. The goal of this section is to identify and investigate high-level geological engineering tasks that should be considered when designing a salt cavern for CAES.Part II of the thesis entails a comprehensive study on the siting of CAES plants in salt caverns across Canada. The objective of the study was to develop an evaluation methodology and use it to determine suitable sites for CAES based on geology, renewable energy potential, energy demand, and existing infrastructure. Multi-criteria analysis was utilized as a tool to compare and evaluate sites. Six criteria are used in the evaluation framework: 1) depth to salt strata, 2) salt strata thickness, 3) renewable energy potential, 4) energy demand, 5) proximity to existing natural gas infrastructure, and 6) proximity to existing electrical infrastructure. The study will be useful to the government in developing energy policies, drafting regulations, and utilized by the industry in deciding the location for front-end engineering and design (FEED) studies. Part III of the thesis comprises of a study on the potential of deep brine disposal in southwestern Ontario. The aim of the study was to develop an evaluation methodology and investigate suitable sites for brine disposal in southwestern Ontario based on geological, geomechanical, and petrophysical parameters. A multi-criteria analysis evaluation system was developed based on relevant disposal parameters and applied to sites throughout southwestern Ontario. Criteria used in the study include permeability, porosity, depth, thickness, disposal formation lithology, and caprock lithology. The study will benefit industrial and academic readers to understand the parameters required for deep brine