TODAY’S STUDY: TRANSMISSION AND THE EV

The thing that makes change most challenging is that it is layered. Take, for instance, the transition from the internal combustion engine (ICE) powered by gasoline to the plug-in electric vehicle (PEV) powered by batteries charged from the transmission system.

Making high-quality, practical and affordable battery-powered vehicles has been difficult enough. But seeing modern society from the nozzle to the plug goes far beyond making the right cars. As detailed in the study highlighted below, an infrastructure with which to charge the vehicles and many more changes will also be necessary.

Most charging is expected to take place at home but an infrastructure that provides for charging at the work place and at the many public places where cars go must be available if drivers are to enjoy the flexibility and freedom they have grown used to with ICE-powered personal transport.

The nation’s transmission system must also be ready to face change. Demands on it could accelerate. If vehicle charging is allowed to follow a pattern like prime time television viewing or rush hour commuting, the grid could be put under serious duress. If a peak charging period happens from the end of the evening rush hour to the end of the evening’s prime time TV viewing, new supplies of New Energy may not be serviceable because that would be just after the sun goes down to just before most winds pick up.

Change, though, also offers opportunities. Planners and entrepreneurs have already begun seizing them. Competition between makers and providers of home and public charging stations is robust.

Smart grid and smart meter technologies are being built into grid operations, home electrical systems and vehicle controls. They will support power-price schedules and and automation designed to shift PEV charging to off-peak times when winds are high, excess electricity is common and grids could benefit from more demand. Entrepreneurs in these areas are now earning billions and the sector is expected to expand exponentially.

Cost-effective energy storage systems are being built into existing New Energy generating plants. Less expensive, more capable systems are being designed for bigger New Energy power plants. Stored solar power may soon join high morning winds in making the the bulk of the electricity driving PEVs emissions-free.

Even with its inherent opportunities, change is challenging. It is comforting to know the burden of it is not imaginary and it is exciting to know it also brings opportunities but there is something else.

Change is one of the most essential attributes of life. It is not necessarily typified by outward turmoil. Many living creatures – some who are reading these words – may be going through profound and exciting change without manifesting anything more dramatic than a slightly depressed demeanor or a slightly anxious manner.

Others, of course, are filled with sound and fury.

Either way, life generates changes. Change can create anything.

The transition to the plug-in vehicle promises to facilitate nothing less than a new modernity. It promises lower cost personal transport. It will likely decentralize the vehicle fueling system. It could very well be pivotal in an even more important transition to a New Energy economy.

These benefits or unexpected consequences may come instead or may follow.

Only one thing is certain:

From BlackAsWhite1

Transportation Electrification; A Technology Overview
M. Duvall, M. Alexander, et. al., July 2011 (Electric Power Research Institute)

Abstract

This report provides a detailed status on the commercial rollout of plug-in vehicles. It describes the key vehicle and infrastructure technologies and outlines a number of potential roles for electric utilities to consider when developing electric transportation readiness plans. These roles have been formulated with the objectives of enabling utilities to demonstrate regional leadership in planning for transportation electrification, to support customer adoption of plug-in vehicles and their supporting charging infrastructure, and to understand and minimize the system impacts from vehicle charging.


Executive Summary

Introduction

A new era of Plug-In Electric Vehicles (PEVs) has begun. Nissan and General Motors have each launched a production plug-in electric vehicle in December, 2010. They will be followed by Ford, Mitsubishi, Toyota, Tesla, and others, all of whom have announced the introduction of plug-in vehicles to the U.S. market by 2011 or 2012. The rapidly approaching commercialization of plug-in hybrid and electric vehicles has created an urgent need for utilities to support the adoption of electric vehicles by their customers, to prepare for the installation of residential, commercial, and private infrastructure in their service territories, and to manage the impact of these new loads on the electric distribution system.

This purpose of this report is to provide a detailed status on commercial rollout of plug-in vehicles, to describe the key vehicle and infrastructure technologies, and to outline a number of potential roles for electric utilities to consider when developing electric transportation readiness plans. These roles have been formulated with the objective of enabling utilities to demonstrate regional leadership in planning for transportation electrification, to support customer adoption of plug-in vehicles and supporting charging infrastructure, and to understand and minimize the system impacts from vehicle charging.

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Market Status of Plug-In Electric Vehicles

Plug-In Electric Vehicle Technologies

Plug-in electric vehicles are a family of electric-drive vehicles…with the capability to recharge using grid electricity. PEVs generally include battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs). A BEV’s sole source of energy is the electricity contained in the battery system and must be recharged when depleted to continue operating the vehicle. A PHEV adds a combustion engine to allow extended driving even with a fully depleted battery. One type of PHEV, the Extended Range Electric Vehicle (EREV), operates in similar fashion to a BEV, fully using battery energy before switching to hybrid operation where gasoline is the primary source of energy.

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Commercial Availability of Plug-In Vehicles

Large scale commercial production of plug-in vehicles has only just begun in the United States. Prior to the commercial release of the Chevrolet Volt and Nissan Leaf, there were only a few thousand highway-capable electric vehicles in the United States. This existing fleet includes legacy electric vehicles from the 1990s, limited production Tesla Roadsters and BMW Mini-E electric vehicles, aftermarket conversions of hybrid vehicles to plug-in hybrids, and homebuilt or recreational electric vehicles. The first mass produced consumer vehicles began delivery in December 2010—the Chevrolet Volt extended range electric vehicle (a type of plug-in hybrid) and the Nissan Leaf battery electric vehicle. As of May 31st, 2011, Chevrolet had delivered 2,510 Volts and Nissan 2,186 Leafs…Introduction of plug-in vehicles into automotive product lines will likely happen relatively quickly as most major manufacturers have announced production plans for one or more vehicle models.

For medium and heavy-duty commercial vehicles, there are a number of development and limited production programs building light, medium, and heavy-duty commercial fleet vehicles for on-road use. These include delivery vans, small and large transit buses, utility service vehicles, and urban delivery trucks. Non-road electric transportation—which includes electric lift trucks and material handling equipment, airport ground support equipment, truckstop electrification, port electrification, and mining and overland conveyors—has a large inventory of available products that are generally cost competitive with internal combustion equipment at significantly lower greenhouse gas and criteria emissions.

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Charging Infrastructure

Charging infrastructure is a crucial aspect of PEV operation. Virtually all PEVs require at least one readily available EVSE at their ‘home’ parking location—at a residence, parking facility, fleet yard, etc. Residential EVSE infrastructure is the highest priority—national travel survey data shows that vehicles spend 66% of their time parked at home. Employer-provided workplace is also important as vehicles spend 14% of their time parked at work. A public infrastructure is required to provide for the safe recharge and reliable operation of battery electric vehicles. Public infrastructure also increases the electric utility of plug-in hybrids, allowing them to travel greater distances on electricity.

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Overview of Charging Equipment

There are a number of different ways to recharge PEVs at power levels ranging from less than one kilowatt (kW) to as much as 250 kW at charging times of less than 30 minutes to more than 24 hours. Most residential and public charging will occur at power levels ranging from less than 1 kW to as much as 19.2 kW and full charge times of 3 – 8 hours. Charging is grouped into two classifications based whether the electricity delivered to the charge port on the vehicle is alternating current (AC) or direct current (DC). With AC charging, an on-board charger (an AC-DC converter) transforms the supply into DC electricity for storage in the battery. In all cases control systems on board the vehicle have ultimate control over the charging process.

AC charging is governed by SAE Recommended Practice J1772 (SAE J1772). Devices called Electric Vehicle Supply Equipment (EVSE) are used to safely control the delivery of AC electricity to the vehicle.

There are currently two classifications, referred to as levels for AC charging in North America. Level 1 charging delivers 120 volts AC (VAC) and the EVSE generally consists of a self-contained cordset that terminates in a standard NEMA 5-15R plug compatible with any standard 120 volt household outlet. Level 2 charging delivers 208 – 240 VAC and requires a permanently connected EVSE. The EVSE is typically hard-mounted, either to a wall or a pedestal and supplied by a dedicated circuit. Both Level 1 and Level 2 charging utilize the same connector design at the vehicle and most vehicles can charge at either voltage through the same charge port. Level 1 AC charging is generally limited to 1.44 kW. Level 2 can reach 19.2 kW, with most vehicles and installations using a more modest 3.3 – 6.6 kW.

DC charging, often referred to as ‘fast charging,’ uses an off-board charging station to convert AC electricity to DC and directly charge the vehicle battery without the need for an onboard charger. Its primary purpose is to enable the rapid recharge of battery electric vehicles. The maximum charging power for a vehicle depends on the battery chemistry and system design. BEVs have already been designed and tested for DC charging at rates of 50 – 60 kW.

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Infrastructure Costs

The initial installation of an EVSE can be a significant cost of PEV ownership. Current costs for Level 2 EVSE equipment range from just under $500 to several thousand dollars, depending on the design and capabilities of the equipment. Costs are declining rapidly and most manufacturers indicate nearterm availability of Level 2 EVSE at unit prices approaching $1000. Historical installation data indicates that a typical residential EVSE installation will cost approximately $1,500. Commercial installation cost estimates vary considerably, from $2,500 to $6,000 per EVSE. Installation costs are also likely to decrease as familiarity with the charging infrastructure improves.

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Infrastructure Ownership Models

Outside personally owned residential charging infrastructure (a home EVSE) there are roughly five models of ownership for charging infrastructure:

1. Municipally owned and operated for public benefit, similar to traffic signals, street lights, etc. Supported through municipal budgets.

2. Utility owned and operated for public benefit. Supported in the utility rate base.

3. Employer owned and operated as an employee Benefit

4. Privately owned primarily to enhance an unrelated business—retail shopping, hotels, restaurants, private parking facilities, etc.

5. Privately owned and operated for the sole purpose of providing charging services to PEV owners.

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Plug-In Electric Vehicle Adoption Forecasting – Energy and Climate Impacts

PEV Market Adoption Forecasting

Attempting to forecast the rate of adoption of PEVs is a difficult, highly uncertain task. It is also a necessary step towards understanding and preparing for the grid impacts of PEV charging, estimating the positive energy, climate, and other environmental benefits, and planning infrastructure.

EPRI has developed a PEV adoption model consisting of two primary components, preliminary PEV adoption scenarios out to 2030 and a regional (county-specific) model based on vehicle miles traveled (VMT) data.

This model enables forecasting of the impacts if PEV adoption at the county, state, or national level. It is important to note that our understanding of rate of PEV adoption will change frequently as this new market developed—therefore PEV adoption scenarios must also change continually to reflect new information as it becomes available.

EPRI developed three scenarios to forecast the impacts of low, medium, and high projected rates of PEV adoption between 2010 and 2030. The low scenario is primarily patterned after HEV sales performance from 2000 to 2008 and predicts total PEV sales in the United States of 600,000 vehicles in 2015, 3.1 million by 2020, and slightly fewer than 15 million by 2030.

The medium scenario is based on HEV sales combined with announced manufacturer plans for PEV models and production volume. The medium scenario projects 1.2 million PEVs by 2015, 5.8 million by 2020, and nearly 35 million by 2030. The high scenario is an optimistic view of PEV adoptions and forecasts 2.4 million PEVs by 2015, 12 million by 2020, and over 65 million by 2030. Regardless of scenario, the electrification of the passenger vehicle fleet in the U.S. is a long-term event.

As an example of regionally specific analyses, the results for several states are included in the report.

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Energy and Climate Impacts of PEV Adoption

The results of PEV adoption forecasting can be used to also project energy and climate impacts. This report shows electricity consumption, gasoline savings, and CO2 reduction for each of the adoption scenarios. The regional nature of this model allows for the incorporation of regionally specific data or forecasts for the environmental, energy, or economic characteristics of electricity, gasoline, and other fuels.

For the medium scenario, electricity consumption from PEV adoption is forecasted at 4.4 terawatt-hours (TWh) in 2015, rising to 16 TWh in 2020 and nearly 80 TWh in 2030. This electricity displaces about 380 million gallons of gasoline in 2015, 1.4 billion in 2020 and 7.0 billion in 2030. CO2 emissions decrease due to this net change in energy consumption—electricity is a lower carbon transportation fuel than gasoline. The net reduction is 2.1 million metric tons in 2015 and increases by approximately 2 million metric tons per year, to nearly 48 million metric tons per year in 2030.

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Grid Impacts of Plug-In Electric Vehicles

The charging of PEVs has the potential for both positive and negative impacts to the electric grid. Understanding and addressing potential PEV impacts to the electric grid is a critical role for the electric utility and a key enabler of both widespread PEV adoption and maximizing the benefits of transportation electrification.

PEV Charging Patterns and Load Shapes

The timing of PEV charging is a key determining factor of the grid impacts. It is important to understand the statistical driving patterns that are likely to impact charging behavior. This includes both the time a vehicle arrives home and the distance it drove, which will govern its total electricity demand. For residential charging, the general case is that a PEV will begin charging after is arrives at home and is plugged in.

National Personal Transportation Survey (NPTS) data indicates that the peak arrival time is 5-6 pm, however only about 12% of vehicles arrive home during this hour, leading to a distribution of charging onset times.

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This results in an effective peak charging load of about 700 watts per vehicle. So while residential charging power levels vary from about 1.4 to 7.7 kW, the average impact of a single vehicle on the electric system is far lower.

There are significant efforts underway to alter the load shape generated by PEV charging, whether by use of electricity pricing incentives, actively managed or ‘smart’ charging, or onboard programming of charging times.

These would have the effect of moving the load off the peak. In an ideal scenario, charging for many PEVs could be delayed until after 9 pm with the expectation that every vehicle must be completely charged by the early morning. In this case, the per vehicle electricity demand is still about 700 watts per vehicle, only it is now relatively steady from about 11 pm to 3 am. So while the demand is roughly the same, it now occurs at a time of much lower total electricity demand.

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Evaluation of PEV Distribution System Impacts

At a system level, due to diversity, the electricity demand of PEVs is relatively low, likely resulting in minimal impacts to utility generation and transmission assets, particularly in the near term. At the distribution level, there are numerous transformers and other assets that are designed to serve only a small number of customers. These assets benefit far less from diversity and should receive greater study and analysis as to how they might be impacted by PEV charging. This is a normal part of the utility distribution planning process. EPRI has conducted numerous detailed and sophisticated studies of the distribution system impacts of PEV charging to enable utilities to understand the impacts of this new load on their systems and to augment their planning processes for the additional demand on their systems.

While there are many different distribution systems design practices among utilities and each distribution circuit is different some conclusions of this analysis are:

 Diversity of vehicle location, charging time, and energy demand will minimize the impact to utility distribution systems

 Level 1 charging generates the fewest distribution system impacts

 Higher power Level 2 charging generates the strongest system impacts and is typically not required for most customer charging scenarios

 Short-term PEV impacts for most utility distribution systems are likely minimal and localized to smaller transformers and other devices where the available capacity per customer is already low

 Controlled or managed charging can defer system impacts for a significant period of time

EPRI believes that potential stresses on the electric grid can be fully mitigated through asset management, system design practices, and at some point, managed charging of PEVs to shift a significant of load away from system peak. A proactive utility approach of understanding where PEVs are appearing in their system, addressing near-term localized impacts, and developing both customer programs and technologies for managing long-term charging loads is most likely to effectively and efficiently enable even very large-scale PEV adoption.

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Electricity Pricing for Plug-In Vehicles

Electricity is a low-cost transportation fuel that has been historically stable in its pricing relative to gasoline.

At current U.S. gasoline prices and average electricity rates, plug-in vehicles can be driven for roughly one-third to one-fourth the cost of a gasoline-powered vehicle. Time-of-use (TOU) electricity pricing is generally seen as an effective way to provide an economic incentive for PEV drivers to charge during off-peak hours, minimizing the cost of electricity and reducing stress on the grid—with the limitation that electricity is so much less expensive than gasoline in most areas that PEV drivers may still choose to charge at peak electricity rates to ensure their vehicle is sufficiently charged. Some consumer research indicates that consumers are generally receptive to the idea of off-peak charging given a reasonable economic incentive.

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Potential Roles for the Electric Utility

There are number of potential roles for an electric utility that can support the commercial introduction of electric vehicles, increase customer adoption, provide support to utility customers, and minimize adverse impacts to the electric grid. Each role described in this report must be considered for its overall feasibility given the utility’s specific objectives and regulatory requirements. These include:

1. Customer outreach and education. The utility leverages its relationship with its customers to educate them and create awareness of the different plug-in vehicle technologies and related charging infrastructure.

2. Development of critical infrastructure and services to support the safe and secure operation of electric vehicles throughout a utility’s service territory.

3. Facilitate the implementation of residential, commercial, and public charging infrastructure throughout a utility service territory.

4. Understand and mitigate potential system impacts—specifically to the distribution system—by analyzing its distribution system and understanding likely rates of PEV adoption and geographic clustering.

5. Adopt plug-in vehicles within the utility fleet and install supporting infrastructure.

6. Conduct an active research, development, and demonstration program to acquire useful knowledge and data of the real-world operation of PEVs and to contribute to and understand the development of new technologies