Alternate Fuel Vehicles

Zero-Emission Bus Implementation Guidebook for California Transit Fleets

Tim Lipman
Emily Rogers
2023

Transit bus operations in California are experiencing new challenges due to economic conditions and the ongoing global pandemic. A confluence of factors has created a focus on this critical public-needs serving industry, due to state and local efforts to reduce emissions of pollutants and climate-changing gases. Transit bus operations in California provide essential and additional useful services that offer critical mobility to needy populations (elderly and handicapped) as well as many other groups for whom transit buses provide the most economical, convenient, and low-emission options....

Comprehensive Review of California's Innovative Clean Transit Regulation: Phase I Summary Report

Matthew Jeffers
Kenneth Kelly
Tim Lipman
Andre Fernandes Tomon Avelino
Caley Johnson
Mengming Li
Matthew Post
Yimin Zhang
2022

This report–prepared by NREL and UC Berkeley for the California Air Resources Board (CARB)–provides a comprehensive review conducted for implementation of the Innovative Clean Transit (ICT) regulation and deployment of zero-emission transit buses in California. The ICT regulation requires California transit agencies to begin transitioning to zero-emission vehicle technologies, defining an increasing percentage of new bus purchases that must be zero-emission buses (ZEBs) each year. The purchase requirements begin in 2023, increasing to a 100% ZEB purchase requirement beginning in 2029. This...

Hydrogen Can Have a Much Lower Carbon Intensity than Fossil Fuels But This Largely Depends on How It Is Produced and Distributed

Tim Lipman
Arpad Horvath
Stephanie Collins
Allisa Kendall
Lewis Fulton
Pablo Busch
2022

As interest in hydrogen as an energy carrier has increased, the various ways that hydrogen is made are being categorized as “green,” “blue,” “gray,” and other colors in relation to their environmental impact. While these categorizations are somewhat useful to indicate the environmental and climate change impacts of different production pathways, they are not especially useful for policy making or industry decisionmaking purposes because they are subjective. For example, most definitions of green pathways for hydrogen production only include electrolysis from renewable electricity sources;...

Advanced Materials Supply Considerations for Electric Vehicle Applications

Tim Lipman
Petra Maier
2021

Electric vehicles are now proliferating based on technologies and components that in turn rely on the use of strategic materials and mineral resources. This review article discusses critical materials considerations for electric drive vehicles, focusing on the underlying component technologies and materials. These mainly include materials for advanced batteries, motors and electronics, lightweight structures, and other components specific to each vehicle type. Particularly strategic and widely used minerals and elements/structures for electric vehicles include nickel, cobalt, rare-earth...

The Rise of Electric Vehicles—2020 Status and Future Expectations

Matteo Muratori
Marcus Alexander
Doug Arent
Morgan Bazilian
Pierpaolo Cazzola
Ercan Dede
John Farrell
Chris Gearhart
David Greene
Alan Jenn
Matthew Keyser
Tim Lipman
Sreekant Narumanchi
Ahmad Pesaran
Ramteen Sioshansi
Emilia Suomalainen
Gil Tal
Kevin Walkowicz
Jacob Ward
2021

Electric vehicles (EVs) are experiencing a rise in popularity over the past few years as the technology has matured and costs have declined, and support for clean transportation has promoted awareness, increased charging opportunities, and facilitated EV adoption. Suitably, a vast body of literature has been produced exploring various facets of EVs and their role in transportation and energy systems. This paper provides a timely and comprehensive review of scientific studies looking at various aspects of EVs, including: (a) an overview of the status of the light-duty-EV market and current...

Charging Infrastructure Demands of Shared-Use Autonomous Electric Vehicles in Urban Areas

Hongcai Zhang
Colin Sheppard
Tim Lipman
Teng Zeng
Scott Moura
2020

Ride-hailing is a clear initial market for autonomous electric vehicles (AEVs) because it features high vehicle utilization levels and strong incentive to cut down labor costs. An extensive and reliable network of recharging infrastructure is the prerequisite to launch a lucrative AEV ride-hailing fleet. Hence, it is necessary to estimate the charging infrastructure demands for an AEV fleet in advance. This study proposes a charging system planning framework for a shared-use AEV fleet providing ride-hailing services in urban area. We first adopt an agent-based simulation model, called BEAM...

Joint Fleet Sizing and Charging System Planning for Autonomous Electric Vehicles

Hongcai Zhang
Colin Sheppard
Tim Lipman
Scott Moura
2020

This paper studies the joint fleet sizing and charging system planning problem for a company operating a fleet of autonomous electric vehicles (AEVs) for passenger and goods transportation. Most of the relevant published papers focus on intracity scenarios and adopt heuristic approaches, e.g., agent based simulation, which do not guarantee optimality. In contrast, we propose a mixed integer linear programming model for intercity scenarios. This model incorporates comprehensive considerations of 1) limited AEV driving range; 2) optimal AEV routing and relocating operations; 3) time-varying...

Emerging Technologies for Higher Fuel Economy Automobile Standards

Tim Lipman
2017

Transportation systems contribute significantly to air pollution and ∼15% globally and ∼25% in the United States to emissions climate-changing gases. In the United States, the Corporate Average Fuel Economy (CAFE) standards for motor vehicles were significantly raised in 2012 for the first time in almost three decades. The standards now call for an average across manufacturers of 54.5 miles per gallon (mpg) for new passenger cars by 2025, or 163 grams per mile (g/mi) of greenhouse gas (GHG) emissions, and of 47 mpg (196 g/mi) by 2021. The light truck standards, which include minivans and...

Wind-Assist Marine Demonstration for San Francisco Bay Ferry Districts: Prospects for Saving Diesel Fuel with Wind Power

Tim Lipman
2015

This sailing vessel testing, data collection and analysis project examined the “real world” potential for a novel carbon-fiber “wingsail” technology to reduce fuel use in potential passenger ferryboat applications. In the study, a series of controlled tests were performed, accomplished by using a wingsail wind-assist technology developed by Wind+Wing Technologies. The project involved building a carbon fiber wingsail that was then mounted on a 42-foot (14-meter) trimaran test vessel. The test vessel was outfitted with a complete instrumentation package with data-recording capability. The...

Driver Response to Hydrogen Fuel Cell Buses in a Real-World Setting: Study of a Northern California Transit Bus Fleet

Tim Lipman
Ananda Gray-Stewart
Jeffrey Lidicker
2015

This study examined bus drivers' acceptance of fuel cell electric buses in Alameda–Contra Costa Transit in the San Francisco Bay Area of California. Of the 145 surveys issued, 47 drivers completed a written survey, for a 32% response rate. The study focused on a key attribute for potential success of alternative urban bus technology: the driver acceptance factor. Technology performance flaws that are undesirable or annoying to the bus drivers may also be disruptive to passengers. Furthermore, because of using the buses throughout their full duty cycle, drivers are in a unique position to...