The impacts of climate change—including rising temperatures, changing precipitation patterns, declining snowpack, and more frequent extremes—are already occurring, and are projected to intensify, around the world. As both a source of greenhouse gas (GHG) emissions and an infrastructure system vulnerable to such climate change impacts, the electricity sector faces a dual mitigation and adaptation challenge: decarbonizing generation with renewable sources, while also adapting to changing resource availability and demands under climate change. Long-term electricity resource planning—which has historically focused on minimizing the cost of building and operating the grid to maintain reliability—must therefore shift to plan for climate resilience. Climate-resilient electricity systems are flexible, efficient, diverse, and redundant to be able to respond to climate stressors and maintain clean, reliable, cost-effective electricity. Further, climate change does not affect the electricity system in isolation. Failing to account for cross-sectoral interactions in planning may overlook cascading vulnerabilities, and lead to unintended consequences that jeopardize system resilience. Therefore, grid planners must also account for interactions with other sectors and their feedbacks on electricity supply and demand. However, methods for considering cross-sectoral interdependencies and resilience under climate change are both understudied in the literature and not part of electricity system planning in practice. To address these challenges, in this dissertation I study the electricity systems of the Western United States (WUS), and the case of California—a state that is the world’s sixth largest economy, the 12th largest source of GHG emissions, and one of North America’s most “climate-challenged” regions in terms of impacts such as water stress and extreme heat. In my dissertation chapters, I focus on the cross-sectoral interactions between the electricity and transportation systems, and between the electricity and water systems. Grounded in systems thinking, I uniquely tie together transportation, water, and energy resource operations and planning methods, in consideration of sectoral differences in management and modeling. My research is informed by both academic literature and engagement with key stakeholders through co-production to improve the decision-relevance of the results. Overall, by evaluating how climate mitigation strategies, climate impacts, and adaptation measures across sectors affect grid outcomes, I aim to demonstrate the value of, and necessity for, modernizations to the electricity system planning paradigm to increase climate resilience and account for cross-sectoral dynamics.
In Chapter 1, I analyze the interplay between electricity decarbonization and transportation electrification, otherwise known as vehicle-grid integration. These energy transitions require planners to consider how electric vehicle (EV) charging can complement, rather than challenge, grid operations. However, there is no consensus on the value and feasibility of EV charge management strategies for a highly renewable grid, such as that of California, because electricity markets and charging behaviors are often inadequately represented in the literature. Through a novel linkage of an agent-based mobility model and a high-resolution electricity dispatch model, this chapter quantifies the achievable benefits, in terms of avoided grid operating costs and renewable curtailment, of managed charging compared to the unmanaged charging alternative.
In Chapter 2, I study the interactions between electricity and water systems, commonly referred to as the energy-water nexus. Electricity is used to power all stages of the managed water cycle including water extraction, conveyance, treatment, distribution, use, and disposal. However, the implications of evolving water and electricity systems on the energy usage and GHG associated with California’s water are not clear. Chapter 2 forecasts the energy and GHG footprint related to urban and agricultural water in California out to 2035, given recent trends in declining water demand, shifts to local water sources, and increasing renewable energy on the grid. By evaluating different water sector pathways, the analysis demonstrates the energy and GHG savings co-benefits of water conservation across different regions, which can help in achieving state climate mitigation goals.
Climate change is likely to stress the interactions between electricity and water resources highlighted in Chapter 2. However, the ways and extent that such cross-sectoral interdependencies may exacerbate or offset climate change impacts and related adaptation strategies are unclear. Chapter 3 synthesizes the fragmented literature and develops a generalized framework for understanding how climate change may affect the energy-water relationship. A case study of California by the end-century—when climate impacts on water supply, air-conditioning demand, and hydropower are expected to be greatest—finds that energy requirements of some water sector adaptation strategies may exceed the direct climate impacts on the energy system, demonstrating the value of cross-sectoral coordination to ensure efficient and reliable energy and water provision.
Despite the compounding risk of climate change on coupled energy-water systems shown in Chapter 3, most electricity planning models omit these interactions, which could result in future capacity shortfalls from unanticipated resource changes. Chapter 4 fills this gap with a novel model linkage that evaluates the range of climate impacts on water resources across the WUS, and how the buildout of the region’s electricity system may subsequently need to change to account for, and maintain resilience in the face of, changes in hydropower availability and energy use related to water. The results quantify the additional redundancy and diversity, in terms of generation and transmission capacity resources, needed to make the grid resilient to both water-related climate change impacts and decarbonization.
While many benefits of coordination have been demonstrated in the literature, in the independently managed energy and water sectors, cross-sectoral interactions are still not typically or explicitly operationalized into decision-making. One possible explanation for this gap between the theory and practice of the nexus is that scientists working at the nexus may not be engaging directly with stakeholders to understand and adjust their research based on the kind of information, norms, and methods used by practitioners. Chapter 5 uses a co-production approach through a focus group and surveys with water managers to improve the decision-relevance of Chapter 4 modeling efforts. The results highlight the climate impacts of concern to WUS water managers for providing reliable water services, the explicit and implicit ways that energy interactions affect water management decisions, the diverse tradeoffs managers consider when weighing decisions, and the metrics they use to evaluate the tradeoffs.
I conclude the dissertation with a summary of ongoing work as well as recommendations for both policy-makers and researchers on ways to evaluate and plan for cross-sectoral dynamics and climate resilience for the electricity system.
