Assessing Vehicle Electricity Demand Impacts on California Electricity Supply
Assessing Vehicle Electricity Demand Impacts on California Electricity Supply

Author: Ryan William McCarthy

Publisher:

Published: 2009

Total Pages:

ISBN-13: 9781109662078

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Achieving policy targets for reducing greenhouse gas (GHG) emissions from transportation will likely require significant adoption of battery-electric, plug-in hybrid, or hydrogen fuel cell vehicles. These vehicles use electricity either directly as fuel, or indirectly for hydrogen production or storage. As they gain share, currently disparate electricity and transportation fuels supply systems will begin to "converge." Several studies consider impacts of electric vehicle recharging on electricity supply or comparative GHG emissions among alternative vehicle platforms. But few consider interactions between growing populations of electric-drive vehicles and the evolution of electricity supply, especially within particular regional and policy contexts. This dissertation addresses this gap. It develops two modeling tools (EDGE-CA and LEDGE-CA) to illuminate tradeoffs and potential interactions between light-duty vehicles and electricity supply in California. Near-term findings suggest natural gas-fired power plants will supply "marginal" electricity for vehicle recharging and hydrogen production. Based on likely vehicle recharging profiles, GHG emissions rates from these plants are more than 40% higher than the average from all generation supplying electricity demand in California and 65% higher than the estimated marginal electricity emissions rate in California's Low Carbon Fuel Standard. Emissions from power plants supplying vehicle recharging are usually highest from 5pm-8pm, when they are 20% higher than their typical low value, from 2am-4am. Plug-in hybrid vehicles are 25-42% more efficient than conventional, gasoline hybrids, but reduce GHG emissions by less than 5%, because marginal electricity is currently much more carbon-intensive than gasoline in California (based on likely recharging profiles). Over the long term, adding vehicle recharging or renewable generation to the grid can have important impacts on how electricity is supplied. Vehicle recharging shifts capacity and generation from poorly-utilized peaking power plants to more highly-utilized baseload plants with lower operating costs. Adding renewable generation has the opposite effect, which may be partially mitigated if vehicle recharging can be made to follow renewable generation. Achieving long-term targets for deep reductions in electricity sector GHG emissions requires significantly increasing renewable or nuclear generation and reducing per-capita electricity demand or avoiding new capacity from fossil power plants without carbon capture and sequestration.

Electric Vehicle Charging and the California Power Sector
Electric Vehicle Charging and the California Power Sector

Author: Julia Meagher Sohnen

Publisher:

Published: 2013

Total Pages:

ISBN-13: 9781303540691

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This thesis explores the implications of the increased adoption of plug-in electric vehicles in California through its effect on the operation of the state's electric grid. The well-to-wheels emissions associated with driving an electric vehicle depend on the resource mix of the electricity grid used to charge the battery. We present a new least-cost dispatch model, EDGE-NET, for the California electricity grid consisting of interconnected sub-regions that encompass the six largest state utilities that can be used to evaluate the impact of growing electric vehicle demand on existing power grid infrastructure system and energy resources. This model considers spatiality and temporal dynamics of energy demand and supply when determining the regional impacts of additional charging profiles on the current electricity network. Model simulation runs for one year show generation and transmission congestion to be reasonable similar to historical data. Model simulation results show that average emissions and system costs associated with electricity generation vary significantly by time of day, season, and location. Marginal cost and emissions also exhibit seasonal and diurnal differences, but show less spatial variation. Sensitivity of demand analysis shows that the relative changes to average emissions and system costs respond asymmetrically to increases and decreases in electricity demand. These results depend on grid mix at the time and the marginal power plant type.In minimizing total system cost, the model will choose to dispatch the lowest-cost resource to meet additional vehicle demand, regardless of location, as long as transmission capacity is available. Location of electric vehicle charging has a small effect on the marginal greenhouse gas emissions associated with additional generation, due to electricity losses in the transmission grid. We use a geographically explicit, charging assessment model for California to develop and compare the effects of two charging profiles. Comparison of these two basic scenarios points to savings in greenhouse gas emissions savings and operational costs from delayed charging of electric vehicles. Vehicle charging simulations confirm that plug-in electric vehicles alone are unlikely to require additional generation or transmission infrastructure. EDGE-NET was successfully benchmarked against historical data for the present grid but additional work is required to expand the model for future scenario evaluation. We discuss how the model might be adapted for high penetrations of variable renewable energy resources, and the use of grid storage. Renewable resources such as wind and solar vary in California vary significantly by time-of-day, season, and location. However, combination of multiple resources from different geographic regions through transmission grid interconnection is expected to help mitigate the impacts of variability. EDGE-NET can evaluate interaction of supply and demand through the existing transmission infrastructure and can identify any critical network bottlenecks or areas for expansion. For this reason, EDGE-NET will be an important tool to evaluate energy policy scenarios.

The Development and Evaluation of a Highly-resolved California Electricity Market Model to Characterize the Temporal and Spatial Grid, Environmental, and Economic Impacts of Electric Vehicles
The Development and Evaluation of a Highly-resolved California Electricity Market Model to Characterize the Temporal and Spatial Grid, Environmental, and Economic Impacts of Electric Vehicles

Author: Ghazal Razeghi

Publisher:

Published: 2013

Total Pages: 334

ISBN-13: 9781303462061

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Drastic changes need to occur in the electricity generation and transportation sectors in order to address environmental concerns that have attracted attention in recent years. These concerns, combined with increasing energy prices, have led to elevated interest in alternative, and low to non-carbon technologies in both sectors from both researchers and policymakers. In the state of California, integration of renewable resources, and switching to more environmental-friendly transportation options, have been mandated by stringent environmental regulations such as AB 32, AB 118, and RPS goals. A spatially and temporally resolved resource dispatch model is developed that simulates the operations of an electricity market while taking into account all the physical constraints associated with various components of an electricity grid such as transmission system constraints. Multiple modules are also developed to provide inputs to the model and also determine the interaction between electricity generation and transportation sectors. This dispatch model and its modules are used to assess a selected set of future transportation and electricity generation scenarios. These scenarios include various dispatch strategies, integration of renewables, and deploying plug-in electric vehicles. The results show that with appropriate planning, the generation, transmission, and distribution sectors will be able to accommodate a high penetration of plug-in vehicles, and they will result in an overall reduction in criteria pollutant and greenhouse gas emissions. With vehicle smart charging, the need for planning in the generation sector is minimized and the installed generators will be able to handle the extra load caused by the vehicles. Different dispatch strategies are developed and results indicate that the best approach to reduce emissions while keeping the system's costs at acceptable levels is a combination of economic and environmental dispatch strategies. This strategy can also be used to dispatch renewable resources as a part of the market instead of using the current must-take strategy. The methodology and the tools developed provide a means to examine various aspects of future scenarios and their impacts on different sectors, and can be used for decision making and planning purposes.

Role of Electric Vehicles in the U.S. Power Sector Transition: A System-Level Perspective
Role of Electric Vehicles in the U.S. Power Sector Transition: A System-Level Perspective

Author:

Publisher:

Published: 2020

Total Pages: 0

ISBN-13:

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After over a century of petroleum dominance many anticipate that electrification could disrupt the transportation energy landscape. At the same time, the electric power systems are undergoing profound changes: variable renewables are displacing conventional generation sources; distributed generation is disrupting utility business models; energy storage and other new technologies are emerging; and the traditional system based on the premise that generation is dispatched to match an inelastic demand is evolving to create a system with greater participation in power system planning and operations from traditionally passive consumers. In this context, it is important to understand how transportation electrification will impact electricity demand and in turn electricity supply, including changes in the load shapes that characterize the system and the opportunity to leverage flexible electric vehicle (EV) charging to better integrate demand and supply. Assessing the impacts of electrification on the energy system requires an understanding of how it might impact the amount and shape of electricity consumption, and how this electricity can be supplied. In particular, increased adoption of electric vehicles introduces a new source of demand altogether, potentially very flexible. Moreover, electrification could shift the consumption of natural gas between sectors, thereby affecting the economics for natural gas-fired generation relative to other electricity generation options. Several factors will impact the evolution of the power system under a widespread electrified future, which, in turn, could have far-reaching effects on future energy costs and emissions.