Integrating Plug-in Electric Vehicles into California’s Grid System: Policy Entrepreneurship and Technical Challenges

The deployment of large numbers of plug-in electric vehicles (PEVs), in order to satisfy zero-emission-vehicle (ZEV) goals in the State of California, brings both potential benefits and costs for the electric grid. Since early 2009, the issue of so-called vehicle-grid integration (VGI) has become a center-stage policy discussion among the electricity and transportation sectors. This dissertation encompasses three studies related to VGI. By conducting a policy process analysis, the first study addresses the questions of how the policy process for VGI regulations has been formed in California, and what have been the major challenges in policy-making. The results show that a policy window for VGI was opened for the first time by the political stream, through State Senate Bill 626 in 2009, and later, supported by the Governor’s ZEV action plan in 2012. These legislations gave California Public Utilities Commission (CPUC) the authority to implement regulations on enabling PEV load management systems and PEV-based grid services. In response, Energy Division Staff at CPUC became a policy entrepreneur, and has adopted an incremental policy-making strategy targeting investor-owned utilities (IOUs). The two largest barriers facing an effective policy solution are identified as; (1) the complexities involved in quantifying economic value from VGI; and (2) the feasibility concerns about adopting VGI enabling technologies on the grid. The second study focuses on the VGI feasibility issues mentioned above. This study provides a feasibility assessment, focusing on technical and market challenges in VGI. The results show that both, technical and market challenges exist in each of the load management strategies. The findings feature a list of technical and market challenges that need to be taken into consideration by stakeholders in VGI-related decision-making. Finally, the third study develops a stochastic-systems approach to VGI modeling where PEV load management strategies are compared for their economic value to PEV consumers and their local utility companies. The proposed methodology provides several improvements to the VGI modeling literature. These improvements include combining assessments for generation and distribution systems in the same model, and advancing uncertainty analysis for PEV consumer behavior considering real-world data sets

Quantifying the Economic Value of Vehicle-Grid Integration: A Case Study of Dynamic Pricing in the Sacramento Municipal Utility District

This study develops a stochastic-systems approach in modeling vehicle-grid integration (VGI), where load management strategies can be compared in terms of their economic value to plug-in electric vehicle (PEV) consumers and their local utility companies. The proposed methodology is demonstrated in an assessment of VGI for the Sacramento Municipal Utility District (SMUD) in California. Monte-Carlo simulations have been performed to randomly assign PEV charging characteristics of the households based on given statistical distributions. Consumer adoption of time-of-use (TOU) rates is modeled as an optimization problem where consumers seek the earliest PEV charge start time among the charge schedules resulting lowest cost and satisfying their transportation needs. The preliminary results show that, considering today’s grid system, the deployment of 60,000 PEVs in Sacramento Region will have significant but manageable impacts. These impacts included increasing annual peak demand by 86MWs (5%), and overloading up to 101 neighborhood transformers in the distribution system. On the other hand, adopting proper TOU rates presents a high potential for minimizing these negative impacts of widespread PEV deployment on the grid. The proposed methodology provided several improvements to the VGI modeling literature. These improvements included combining assessments for generation and distribution systems in the same model, and advancing uncertainty analysis for the PEV consumer behavior with considering real world data sets

PHEV-EV Charger Technology Assessment with an Emphasis on V2G Operation

More battery powered electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) will be introduced to the market in 2011 and beyond. Since these vehicles have large batteries that need to be charged from an external power source or directly from the grid, their batteries, charging circuits, charging stations/infrastructures, and grid interconnection issues are garnering more attention. This report summarizes information regarding the batteries used in PHEVs, different types of chargers, charging standards and circuits, and compares different topologies. Furthermore, it includes a list of vehicles that are going to be in the market soon with information on their charging and energy storage equipment. A summary of different standards governing charging circuits and charging stations concludes the report. There are several battery types that are available for PHEVs; however, the most popular ones have nickel metal hydride (NiMH) and lithium-ion (Li-ion) chemistries. The former one is being used in current hybrid electric vehicles (HEVs), but the latter will be used in most of the PHEVs and EVs due to higher energy densities and higher efficiencies. The chargers can be classified based on the circuit topologies (dedicated or integrated), location of the charger (either on or off the vehicle), connection (conductive, inductive/wireless, and mechanical), electrical waveform (direct current (dc) or alternating current (ac)), and the direction of power flow (unidirectional or bidirectional). The first PHEVs typically will have dedicated, on-board, unidirectional chargers that will have conductive connections to the charging stations or wall outlets and will be charged using either dc or ac. In the near future, bidirectional chargers might also be used in these vehicles once the benefits of practical vehicle to grid applications are realized. The terms charger and charging station cause terminology confusion. To prevent misunderstandings, a more descriptive term of electric vehicle supply equipment (EVSE) is used instead of charging station. The charger is the power conversion equipment that connects the battery to the grid or another power source, while EVSE refers to external equipment between the grid or other power source and the vehicle. EVSE might include conductors, connectors, attachment plugs, microprocessors, energy measurement devices, transformers, etc. Presently, there are more than 40 companies that are producing EVSEs. There are several standards and codes regarding conductive and inductive chargers and EVSEs from the Society of Automotive Engineers (SAE), the Underwriter Laboratories (UL), the International Electrotechnical Commission (IEC), and the National Electric Code (NEC). The two main standards from SAE describe the requirements for conductive and inductive coupled chargers and the charging levels. For inductive coupled charging, three levels are specified: Level 1 (120 V and 12 A, single-phase), Level 2 (208 V-240 V and 32 A, single-phase), and Level 3 (208-600 V and 400 A, three-phase) . The standard for the conductive-coupled charger also has similar charging ratings for Levels 1 and 2, but it allows higher current ratings for Level 2 charging up to 80 A. Level 3 charging for this standard is still under development and considers dc charging instead of three-phase ac. More details in these areas and related references can be found in this Oak Ridge National Laboratory (ORNL) report on PHEV-EV charger technology assessment

Integrating Plug-in Electric Vehicles into California’s Grid System: Policy Entrepreneurship and Technical Challenges

The deployment of large numbers of plug-in electric vehicles (PEVs), in order to satisfy zero-emission-vehicle (ZEV) goals in the State of California, brings both potential benefits and costs for the electric grid. Since early 2009, the issue of so-called vehicle-grid integration (VGI) has become a center-stage policy discussion among the electricity and transportation sectors. This dissertation encompasses three studies related to VGI. By conducting a policy process analysis, the first study addresses the questions of how the policy process for VGI regulations has been formed in California, and what have been the major challenges in policy-making. The results show that a policy window for VGI was opened for the first time by the political stream, through State Senate Bill 626 in 2009, and later, supported by the Governor’s ZEV action plan in 2012. These legislations gave California Public Utilities Commission (CPUC) the authority to implement regulations on enabling PEV load management systems and PEV-based grid services. In response, Energy Division Staff at CPUC became a policy entrepreneur, and has adopted an incremental policy-making strategy targeting investor-owned utilities (IOUs). The two largest barriers facing an effective policy solution are identified as; (1) the complexities involved in quantifying economic value from VGI; and (2) the feasibility concerns about adopting VGI enabling technologies on the grid. The second study focuses on the VGI feasibility issues mentioned above. This study provides a feasibility assessment, focusing on technical and market challenges in VGI. The results show that both, technical and market challenges exist in each of the load management strategies. The findings feature a list of technical and market challenges that need to be taken into consideration by stakeholders in VGI-related decision-making. Finally, the third study develops a stochastic-systems approach to VGI modeling where PEV load management strategies are compared for their economic value to PEV consumers and their local utility companies. The proposed methodology provides several improvements to the VGI modeling literature. These improvements include combining assessments for generation and distribution systems in the same model, and advancing uncertainty analysis for PEV consumer behavior considering real-world data sets

Quantifying the Economic Value of Vehicle-Grid Integration: A Case Study of Dynamic Pricing in the Sacramento Municipal Utility District

This study develops a stochastic-systems approach in modeling vehicle-grid integration (VGI), where load management strategies can be compared in terms of their economic value to plug-in electric vehicle (PEV) consumers and their local utility companies. The proposed methodology is demonstrated in an assessment of VGI for the Sacramento Municipal Utility District (SMUD) in California. Monte-Carlo simulations have been performed to randomly assign PEV charging characteristics of the households based on given statistical distributions. Consumer adoption of time-of-use (TOU) rates is modeled as an optimization problem where consumers seek the earliest PEV charge start time among the charge schedules resulting lowest cost and satisfying their transportation needs. The preliminary results show that, considering today’s grid system, the deployment of 60,000 PEVs in Sacramento Region will have significant but manageable impacts. These impacts included increasing annual peak demand by 86MWs (5%), and overloading up to 101 neighborhood transformers in the distribution system. On the other hand, adopting proper TOU rates presents a high potential for minimizing these negative impacts of widespread PEV deployment on the grid. The proposed methodology provided several improvements to the VGI modeling literature. These improvements included combining assessments for generation and distribution systems in the same model, and advancing uncertainty analysis for the PEV consumer behavior with considering real world data sets

Coexistence of Granular Cell Tumor with Squamous Cell Carcinoma on the Tongue: A Case Report

Introduction: Granular cell tumors (GCTs) are rare and mostly benign soft tissue tumors. Though they have been reported in all parts of body, they are generally located in the head and neck region, especially on the tongue. Some malign forms exist, but these have been rarely reported. Granular cell tumors have a neural origin and, in immunohistochemical evaluations, they express S-100 and neuron specific enolase (NSE). The treatment of these tumors is bulky surgical excision.   Case Report:   In this case, a cauliflower shaped lesion with a 1 cm diameter was excised from the midline tongue of a 65 year old woman. The histopathological evaluation indicated that it was squamous cell carcinoma (SCC) covering GCT. Herein, the coexistence of GCT and SCC we describe on the same region of the tongue, in accordance with literature review, since this is a very rare condition.   Conclusion: Pseudoepitheliomatous hyperplasia may accompany GCTs on the tongue and this condition may mimic well-differentiated SCC. For this reason, with the help of Ki-67 and p63 expression, in addition to immunohistochemical markers, well-differentiated SCC should be differentiated from pseudoepitheliomatous hyperplasia through careful investigation

Coexistence of Granular Cell Tumor with Squamous Cell Carcinoma on the Tongue: A Case Report

Introduction: Granular cell tumors (GCTs) are rare and mostly benign soft tissue tumors. Though they have been reported in all parts of body, they are generally located in the head and neck region, especially on the tongue. Some malign forms exist, but these have been rarely reported. Granular cell tumors have a neural origin and, in immunohistochemical evaluations, they express S-100 and neuron specific enolase (NSE). The treatment of these tumors is bulky surgical excision.   Case Report:   In this case, a cauliflower shaped lesion with a 1 cm diameter was excised from the midline tongue of a 65 year old woman. The histopathological evaluation indicated that it was squamous cell carcinoma (SCC) covering GCT. Herein, the coexistence of GCT and SCC we describe on the same region of the tongue, in accordance with literature review, since this is a very rare condition.   Conclusion: Pseudoepitheliomatous hyperplasia may accompany GCTs on the tongue and this condition may mimic well-differentiated SCC. For this reason, with the help of Ki-67 and p63 expression, in addition to immunohistochemical markers, well-differentiated SCC should be differentiated from pseudoepitheliomatous hyperplasia through careful investigation

Developing Strategies for Plug-in Electric Vehicle and Smart Grid Integration in California: A Qualitative Analysis of Expert Opinions

This empirical study first identifies vehicle-grid integration (VGI) strategies as discussed by stakeholders in California, then, provides a feasibility assessment for these strategies focusing on technical and market challenges. VGI strategies presented in this paper include four components: (1) plug-in electric vehicle (PEV) load identification and tracking; (2) choice of a load management strategy, (3) deployment of enabling technologies, and, finally, (4) providing grid services and compensating participants. The assessment is performed based on a qualitative analysis of expert opinions gathered by a series of stakeholder interviews. These interviews were conducted with representatives of 18 organizations from the government, electric utility, and PEV sectors. The participants expressed their opinions about potential VGI strategies based on personal or company experiences. The qualitative data is analyzed under three categories of load management, which include dynamic pricing, demand response, and energy storage. The results show that both, technical and market challenges exist in each of the load management strategies, except the most basic dynamic pricing strategy. This strategy, which provides special time-of-use rates for PEV-owner households, is currently being implemented by all major utilities in California. The findings also feature a list of technical and market challenges that need to be taken into consideration by stakeholders in VGI-related decision-making

PHEV-EV Charger Technology Assessment with an Emphasis on V2G Operation

More battery powered electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) will be introduced to the market in 2011 and beyond. Since these vehicles have large batteries that need to be charged from an external power source or directly from the grid, their batteries, charging circuits, charging stations/infrastructures, and grid interconnection issues are garnering more attention. This report summarizes information regarding the batteries used in PHEVs, different types of chargers, charging standards and circuits, and compares different topologies. Furthermore, it includes a list of vehicles that are going to be in the market soon with information on their charging and energy storage equipment. A summary of different standards governing charging circuits and charging stations concludes the report. There are several battery types that are available for PHEVs; however, the most popular ones have nickel metal hydride (NiMH) and lithium-ion (Li-ion) chemistries. The former one is being used in current hybrid electric vehicles (HEVs), but the latter will be used in most of the PHEVs and EVs due to higher energy densities and higher efficiencies. The chargers can be classified based on the circuit topologies (dedicated or integrated), location of the charger (either on or off the vehicle), connection (conductive, inductive/wireless, and mechanical), electrical waveform (direct current (dc) or alternating current (ac)), and the direction of power flow (unidirectional or bidirectional). The first PHEVs typically will have dedicated, on-board, unidirectional chargers that will have conductive connections to the charging stations or wall outlets and will be charged using either dc or ac. In the near future, bidirectional chargers might also be used in these vehicles once the benefits of practical vehicle to grid applications are realized. The terms charger and charging station cause terminology confusion. To prevent misunderstandings, a more descriptive term of electric vehicle supply equipment (EVSE) is used instead of charging station. The charger is the power conversion equipment that connects the battery to the grid or another power source, while EVSE refers to external equipment between the grid or other power source and the vehicle. EVSE might include conductors, connectors, attachment plugs, microprocessors, energy measurement devices, transformers, etc. Presently, there are more than 40 companies that are producing EVSEs. There are several standards and codes regarding conductive and inductive chargers and EVSEs from the Society of Automotive Engineers (SAE), the Underwriter Laboratories (UL), the International Electrotechnical Commission (IEC), and the National Electric Code (NEC). The two main standards from SAE describe the requirements for conductive and inductive coupled chargers and the charging levels. For inductive coupled charging, three levels are specified: Level 1 (120 V and 12 A, single-phase), Level 2 (208 V-240 V and 32 A, single-phase), and Level 3 (208-600 V and 400 A, three-phase) . The standard for the conductive-coupled charger also has similar charging ratings for Levels 1 and 2, but it allows higher current ratings for Level 2 charging up to 80 A. Level 3 charging for this standard is still under development and considers dc charging instead of three-phase ac. More details in these areas and related references can be found in this Oak Ridge National Laboratory (ORNL) report on PHEV-EV charger technology assessment

Integrating Plug-in Electric Vehicles into the Grid: Policy Entrepreneurship in California

The deployment of large numbers of plug-in electric vehicles (PEVs), in order to satisfy zero-emission-vehicle (ZEV) goals in California, brings both potential benefits and costs for the electric grid. Since early 2009, the issue of so-called vehicle-grid integration (VGI) has become a center-stage policy discussion among the electricity and transportation sectors. By conducting a policy process analysis, this research addresses the questions of how the policy process for VGI regulations has been formed in California, and what have been the major challenges in policy-making. A series of interviews were conducted between with representatives of 18 organizations from the government, electric utility, and PEV sectors. The qualitative data is analyzed under the three dimensions of policy process; problem, politics, and policy as suggested by Multiple Streams framework (Kingdon, 1995). The results show that a policy window for VGI regulations was opened for the first time by the political stream, through State Senate Bill 626 in 2009, and later, supported by the Governor’s ZEV action plan in 2012. In response, the California Public Utility Commission became a policy entrepreneur, and has adopted an incremental policy-making strategy targeting investor-owned utilities (IOUs). The two largest barriers facing an effective policy solution are identified as the complexities involved in quantifying economic value from VGI and the feasibility concerns about adopting VGI enabling technologies on the grid