Green Principles, Parametric Analysis, and Optimization for Guiding Environmental and Economic Performance of Grid-scale Energy Storage Systems

The development and deployment of grid-scale energy storage technologies have increased recently and are expected to grow due to technology improvements and supporting policies. While energy storage can help increase the penetration of renewables, reduce the consumption of fossil fuels, and increase the grid sustainability, its integration into the electric grid poses unique sustainability challenges that need to be investigated through systematic sustainability assessment frameworks. The main objective of this dissertation is to develop principles and models to assess the environmental and economic impacts of grid-scale energy storage and guide its development and deployment. The first study of this dissertation is an initial case study of energy storage to examine the role of cost-effective energy storage in supporting high penetration of wind energy and achieving emissions targets in an off-grid configuration. In this study, the micro-grid system includes wind energy integrated with vanadium redox flow battery (VRFB) as energy storage, and natural gas engine. Life cycle greenhouse gas (GHG) emissions and total cost of delivered electricity are evaluated and generation mixes are optimized to meet emissions targets at the minimum cost. The results demonstrate that while incorporating energy storage consistently reduces life cycle GHG emissions in the system by integrating more wind energy, its integration is cost-effective only under very ambitious emission targets. The insights from this case study and additional literature review led to the development of a set of twelve principles for green energy storage, presented in the second study. These principles are applicable to the wide range of energy storage technologies and grid applications, and are developed to guide the design, maintenance, and operation of energy storage systems for grid applications. The robustness of principles was tested through a comprehensive literature review and also through in-depth quantitative analyses of the VRFB off-grid system. An in-depth parametric analysis is developed in the third study to evaluate the impacts of six key parameters (e.g. energy storage service-life) that influence the environmental performance of six energy storage technologies within three specific grid applications (including time-shifting, frequency regulation, and power reliability). This study reveals that round-trip efficiency and heat rate of charging and displaced generation technologies are dominant parameters in time-shifting and regulation applications, whereas energy storage service life and production burden dominate in power reliability. Finally, an optimization model is developed in the fourth study to examine the real-world application of energy storage in bulk energy time-shifting in California grid under varying renewable penetration levels. The objective was to find the optimal operation and size of energy storage in order to minimize the system total costs (including monetized GHG emissions), while meeting the electricity load and systems constraints. Simulations were run to investigate how the operation of nine distinct storage technologies impacted system cost, given each technology’s characteristics. The results show that increasing the renewable capacity and the emissions tax would make it more cost-effective for energy storage deployment. Among storage technologies, pumped-hydro and compressed-air energy storage with lower capital costs, are deployed in more scenarios. Overall, this research demonstrates how sustainability performance is influenced by storage technology characteristics and the electric grid conditions. The systematic principles, model equations, and optimizations developed in this dissertation provide specific guidance to industry stakeholders on design and deployment choices. The targeted audience ranges from energy storage designers and manufacturers to electric power utilities.PHDNatural Resources & EnvironmentUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/143942/1/marbab_1.pd

Plausible Energy Futures: A Framework for Evaluating Options, Impacts, and National Energy Choices.

The global energy system is undergoing major transformations. The world faces a dual challenge of meeting increasing energy demand while reducing greenhouse gas emissions. This change is characterized by the convergence of power, transportation, industrial, and building sectors, and the surge of multi-sectoral integration. Such transformation of energy systems requires a combination of technology selection and policy choices to ensure providing reliable and clean energy. Understanding the implications of these dynamics is challenging and requires a holistic approach to provide systems level insights. In this working paper, we provide an overview of energy transformation analysis and projection tools and discuss the use of quantitative methods to examine possible future energy pathways. This is done to facilitate achieving decarbonization goals by providing thought leaders and policy makers with a robust framework in which energy choices and decarbonization goals can be made based on lifecycle analyses. We synthetize our findings applicable to modeling tools based on discussions with colleagues in other academic institutions and government labs and provide a summary of a wide range of lifecycle assessment (LCA) and energy modeling tools. Our assessment shows that although there is considerable related research work emerging, there is a lack of readily available or generally accepted quantitative models and tools that consider a broad and robust lifecycle analysis approach for a range of plausible energy futures at regional and national levels. Such a tool is needed to help policy makers, industry, investors, and the financial sector to better understand and make decisions on energy choices and energy transitions, and avoid narrowly framed and advocacy-driven pathways. We at MIT have substantial experience in building and maintaining energy system assessment tools: i) A comprehensive system-level and pathway-level lifecycle assessment model, which is called the Sustainable Energy Systems Analysis Modeling Environment (SESAME). SESAME is a publicly available, open access model with multi-sector representation. ii) The Integrated Global System Modeling framework (IGSM), which combines an economy-wide, multi-sector, multi-region computable general equilibrium (CGE) model (The MIT Economic Projection and Policy Analysis model, EPPA) with a natural systems component (The MIT Earth System model, MESM). The IGSM is an integrated assessment model (IAM). To quantify additional environmental impact categories such as air pollutants and water footprint, we develop an expanded SESAME platform. For an economy-wide scenario analysis, we use the MITEI Energy Choice Program Working Paper 3 modeling results from our EPPA model. The expanded SESAME version will be a publicly available technology options and scenario analysis tool that can use input information from any economy-wide system (or use the default settings that represent our base-case values). The tool will evaluate options, impacts, and national energy choices for exploring the impacts of relevant technological, operational, temporal, and geospatial characteristics of the evolving energy system. It focuses on lifecycle analysis with high technology resolution (linked with the existing MIT energy-economic models) that provides economic information and quantifies lifecycle GHG emissions, as well as impacts related to criteria pollutants and water. Such analysis highlights how effective policy choices and technology selection can reduce such environmental impact

The overlooked environmental footprint of increasing Internet use

often recognized too late, typically when changing the adopted technologies and behavioral norms is difficult. A similar story may unfold if society continues to blindly transition to an unregulated and environmentally unaudited digital world, a transition path that has been facilitated by the fourth industrial revolution and is now accelerated by the global COVID-19 crisis. The newly developed digital lifestyle has major environmental benefits, including the reduction of travel-related CO2 emissions. Yet, increased Internet use has some hidden environmental impacts that must be uncovered (Fig. 1a) to make the transition to a lowcarbon and green economy successful. The data centers’ electricity consumption accounts for 1% of the global energy demand (Masanet et al., 2020), more than the national energy consumption of many countries. Depending on the energy supply mix and use efficiency, Internet traffic contributes differently to negative environmental impacts and climate change. As the number of Internet users increases, the number of online services and applications they use grow. This trend exacerbates the environmental footprint of the Internet, despite the many successful and significant efforts to improve the efficiency of data centers (Masanet et al., 2020) and reduce their reliance on fossil energy. In order to build a sustainable digital world, it is imperative to carefully assess the environmental footprints of the Internet and identify the individual and collective actions that most affect its growth

Twelve Principles for Green Energy Storage in Grid Applications

The introduction of energy storage technologies to the grid could enable greater integration of renewables, improve system resilience and reliability, and offer cost effective alternatives to transmission and distribution upgrades. The integration of energy storage systems into the electrical grid can lead to different environmental outcomes based on the grid application, the existing generation mix, and the demand. Given this complexity, a framework is needed to systematically inform design and technology selection about the environmental impacts that emerge when considering energy storage options to improve sustainability performance of the grid. To achieve this, 12 fundamental principles specific to the design and grid application of energy storage systems are developed to inform policy makers, designers, and operators. The principles are grouped into three categories: (1) system integration for grid applications, (2) the maintenance and operation of energy storage, and (3) the design of energy storage systems. We illustrate the application of each principle through examples published in the academic literature, illustrative calculations, and a case study with an off-grid application of vanadium redox flow batteries (VRFBs). In addition, trade-offs that can emerge between principles are highlighted