100% Renewable Transportation by 2045 – Hawaii is Leading the Charge

by Courtney Murtagh, UMTC Intern


In December 2017 Hawaii’s four Mayors committed to 100% renewable public and private transportation by 2045. Meaning all of Hawaii’s cars, busses, trucks and trains will use renewable energy as fuel.

The four mayors – Honolulu Mayor Kirk Caldwell, Maui County Mayor Alan Arakawa, Kauai County Mayor Bernard Carvalho Jr. and Hawaii County Managing Director Wil Okabe, representing Mayor Harry Kim – signed their respective proclamations, solidifying Hawaii’s status as a nation leader in renewable energy.

Hawaii has always been on the forefront of sustainability and in many ways is leading the nation. In 2015, Hawaii’s Governor David Ige signed into law a bill to reach 100% renewable energy consumption by 2045. In June 2017, another law was passed and Hawaii was once again the first state to commit to the Paris climate accord, despite President Trumps decision to pull the U.S. out of the agreement.

Despite Hawaii being the second in the U.S for electric vehicles sales per capita, Hawaii’s ground transportation still accounts for over a quarter of the states imported fossil fuel consumption as well as a quarter of greenhouse gas emissions.

Exuberant gas prices due to the Islands geography and the high cost of importing oil are the reason many Hawaii citizens are readily accepting this act. Locals and leaders alike are hoping that renewable transportation will reduce the cost of living as well as attract businesses and create jobs.

Hawaii is the first state to commit to this goal, but other states including Massachusetts may not be far behind.

In September 2017, a hearing was held to consider the 100% Renewable Energy Act, which would put Massachusetts on the path to obtain 100% of its electricity from renewable resources by 2035, as well as heating and transportation by 2050.

The Bill (S.1849) passed the House on January 23 and is currently being referred to the joint committee on telecommunication, Utilities and Energy.

More than 40 U.S. cities and 100 global companies have committed to 100% renewable energy.

Uber, Lyft…Impacting Traffic and Economic Development

by Matt Mann, Research Program Coordinator



People are taking Uber, Lyft or Transportation Network Companies (TNCs) more these days and often to avoid both parking and drinking and driving.  Although the majority of users are urban base, demand has been increasing in suburbia for Ubering.  TNCs have changed the way people get around and have impacted traffic in many cities.  If these types of rides are a pre-cursor to autonomous vehicles, the additional passenger trips will continue to increase and will also impact economic development.

A recent U.C. Davis study that included 4,000 users in seven major metro areas—Boston, Chicago, Los Angeles, New York, the San Francisco Bay Area, Seattle, and Washington, D.C., between 2014 and 2016 – points to cities increasing in passenger trips and in population, but transit rides and taxi trips decreasing.  The TNCs are the main source that are accommodating the increase in trips and in-turn causing more urban traffic congestion.

This study also found that around 50% of these trips would not have happened at all or would have been done some other way, via transit, walking etc…This coupled with the dead head time, when no passengers are in the vehicle, the TNCs are having a dramatic impact on vehicle miles traveled and congestion.

Currently New York City is the only major metropolitan city that mandates TNCs to report their travel data.  Other cities are able to obtain data but TNCs are not required to share it.  Being able to access and analyze this data can be the key to determining current and future traffic impacts.

Massachusetts passed legislation in 2016, creating a regulatory framework for TNCs. Speaking with Katie Gronendyke, Press Secretary, Executive Office of Energy and Environmental Affairs, the MA Department of Public Utilities Transportation Network Companies Division  does require some TNC travel data to be reported:

274.12: Reporting Requirements

(2) Annually, a TNC shall report to the Division the following: (a) By February 1st of each calendar year, a TNC shall submit a report for the number of Rides from the previous calendar year, including: 1. City or town where each Ride originated; 2. City or town where each Ride ended; 3. Aggregated and anonymized trip route and length (miles and minutes); and 4. Location of Vehicle accidents;

(b) By March 31st of each calendar year, a TNC shall report its intrastate operating revenues for the previous calendar year. If a TNC fails to report its intrastate operating revenues to the Division by March 31st of any calendar year, the Division may estimate a TNC’s intrastate operating revenues. A TNC’s intrastate operating revenue shall include but not be limited to any Rider picked up at the following: 1. Airport; 2. Train station; 3. Bus terminal; or 4. Any other kind of port.

A Big GHG Reduction – An Entire Bus Fleet Goes Electric

by: Matt Mann, Research Program Coordinator

Image result for electric buses stations

Approximately 16,000 diesel buses were replaced with 16,000 electric buses, in the city of Shenchen, China.  This is the single largest replacement for electric buses to-date.  The mass overhaul included not only getting rid of over 16,000 diesel buses, it also included connecting over 500 charging stations and installing over 800 poles to charge the buses.

Not only are the environmental benefits big, with the reduction of Green House Gas (GHG) emissions; the city of Shenchen has become a quieter city, less the bus engine noise.  The city is also on track for long-term cost savings, in the order of not relying on 75% of the bus fuel coming from fossil fuels.

The recently completed MassDOT project Zero Emission Transit Bus and Refueling Technologies and Deployment Status, championed by Lily Oliver, Office of Transportation Planning. This report summarizes the characteristics of three Zero Electric Buses technologies: 1) battery electric buses; 2) fuel cell battery electric buses; and 3) fuel cell plug-in hybrid electric buses, as well as relevant implementations in the U.S., through a comprehensive review of the available literature, an online survey of several transit agencies that have implemented or are planning to implement ZEBs, and interviews with transit agency representatives. The focus is on performance and cost characteristics of these technologies as well as implementation approaches, refueling strategies, and funding mechanisms.

Transportation Sector – Moving from GHGs to Electricity

by: Matt Mann, Research Program Coordinator

Gas vs Hybrid

As Greenhouse Gases (GHGs) continue to contribute to climate change, the biggest contributor is now the transportation sector, taking over from the power plants.  This doesn’t mean there are more emissions coming out of tailpipes; rather less coal is being used and an increase in cleaner natural gas are two of the biggest reasons.  In the long-term, the other reason could also include an increase in demand of electric vehicles.

Transportation emissions have been fairly flat since 2000 and with a slight increase since 2012.  This, coupled with an increase in the way electricity emissions are produced, has allowed planes, trains and automobiles to become the lead emitter of GHGs since the late 1970s.  Electricity demand has also leveled off, as the shift has been away from coal and more on natural gas and renewable energy.

Even though electricity demand has leveled off, the increase demand for electric vehicles could change this.  With a minimal but consistent increase over the last couple of years, electric vehicles are expected to widen their reach and even include electric delivery trucks as well. With electric vehicles becoming more affordable, reliant and convenient, this increase in demand could eventually have a big impact on pollution emitted.

There are a couple recently completed MassDOT research publications on GHGs reduction and electric vehicles, written by One Center Research Affiliates Erin Baker and Song Gao.  Also Shannon Greenwell, from the Office of Transportation Planning at MassDOT, is currently working on a review and analysis of low-cost, quick to deploy, and scalable GHG-reducing investment strategies that would supplement traditional capital investments.

Efficiency Needs to Pay the Bills

by Matt Mann, Research Program Coordinator


Infrastructure maintenance continues to be costly and finding equitable solutions to pay for it will be challenging.  Historically, infrastructure repairs fell on the revenue made from the gas tax.  The gas tax had been a fair way to have all infrastructure users pay their share.  With the purchase of fuel efficient vehicles (eg. Zero emissions vehicles (ZEV) and battery electric vehicles (BEV)) on the rise, especially out west, relaying on trips to the gas pump to fix the highways is not sustainable.

Currently, eight states have passed bills that include a form of assessment on ZEVs and BEVs.  These assessments include an additional registration fee and/or licensing fees.  These two revenue forms do not demand an upstart cost and are easy to implement.  In-terms of other revenue sources (eg. mileage based fees) a couple of states have discussed introducing a bill for this; but the State of Arizona is the only that tried to pass a bill, but it didn’t get any traction.

Even though the sale of vehicles that have zero or reduced emissions is on the rise, putting something in place to track vehicle distance or mileage is still a ways off.  California, who is leading the nation with the number of ZEVs and BEVs, has recently considered developing a mechanism to tax per mile someone who has one of these vehicles.  Ideas that have been discussed include: tracking your mileage every time you pull up to the gas station or charging station; or retro vehicles with a tracker (collecting miles driven).   Tracking miles would require additional funds for operation and administration.

A recent MassDOT published report by UMTC Research Affiliates Song Gao and Michael Plotnikov titled:  Zero Emission Vehicles: Impacts on Transportation Revenue, states that Massachusetts currently pays for their infrastructure maintenance through a state and federal gas tax, vehicle registration fees, and the purchase and use tax.    MA passed a bill earlier this year, promoting electric vehicle use.  There continues to be discussion in MA about other ways users of ZEV and BEV can financially contribute to maintaining the transportation infrastructure.


US: Transit Agencies Cautious on Electric Buses Despite Bold Forecasts – Dr. Christofa and Dr. Pollitt Weigh in

by: Melissa Paciulli, UMTC Manager of Research

electric buses
Chicago Tribune, 2017

One Center Affiliates, Dr. Eleni Christofa and Dr. Krystal Pollitt recently completed research for MassDOT on evaluating electric and other zero emission buses in the U.S. As part of this research, they completed an extensive review of transit agencies’ experience with electric buses across the country.  We asked them to weigh in on a recent article published by Nicholas Groom, from Reuters, December 12, 2017 on MassTransit, which reported that “more than 65,000 public buses plying U.S. roads today, just 300 are electric. Among the challenges: EVs are expensive, have limited range and are unproven on a mass scale.”

Dr Christofa and Dr. Pollitt, argue that based on their findings, “Electric buses have the potential to expand across the fleets of U.S. transit agencies; limiting factors have been driving range and costs. Recent advances in battery technology are moving towards overcoming these hurdles with increases in energy density and decreased battery costs.”

Plug-in and Ride: The Promise and Potential Challenges of Electric Buses

By Tracy Zafian, UMTC Research Fellow

The use of electric buses and other zero emission vehicles (ZEVs) holds great promise to help reduce vehicle emissions and promote a clearer, less polluting transportation sector.

Transit bus systems offer a great venue for deploying and testing the latest ZEV technologies. An estimated 40 U.S. transit systems now include electric-power buses as part of their fleet. To date, bus systems in California have been the greatest adopters of electric buses. The Santa Barbara Metropolitan Transit District began using electric buses in 2003 and currently has 14 in operation. Stanford University Transit presently has a fleet of 23 electric buses, which it launched in 2014. Foothill Transit in Northern California started using electric buses in 2010 and now has 30 in use. Foothill Transit has pledged to change all its buses over to electric power by 2030. Foothill Transit estimates that already, its annual electric buses eliminate the same amount of emissions as 2,424 gasoline-powered cars. A number of other California transit agencies have smaller fleets of electric buses.

Two UMTC Research Affiliates recently developed a comprehensive review of past and current electric bus deployments nationally. This research was led by Professor Eleni Christofa in Civil and Environmental Engineering and Professor Krystal Pollitt in Environmental Health Sciences. The review included discussions of the three main types of electric-power buses currently in use, and of different facets and impacts of transit agencies’ change to electric buses, including areas of challenge.

The primary type of electric bus in use today is the battery electric (BE) bus, and more than 20 U.S. transit agencies have incorporated BE buses into their operations, including the Worcester Regional Transit Authority (WRTA) and the Pioneer Valley Transit Authority (PVTA). BE buses contain an onboard electric battery, which provides all their power. These batteries are typically re-charged through plug-in stations; BE buses also capture and then use energy from regenerative braking. BE buses have no direct vehicle emissions, but there may be atmospheric pollutants associated with the generation of electricity used for charging their onboard batteries. One potential challenge with BE buses is the short driving range (30 to 130 miles) before needing to be recharged, and the impact of the need for recharging on route scheduling. These buses will typically be recharged at bus stop charging stations during their routes for quick charges (5 to 15 minutes). Some transit agencies also utilize slower charging stations at a central location such as a bus garage, for when BE buses are out of service. Even with the quick charges, it is important that bus schedules be adjusted to reflect the charging time.

BE buses are more expensive to purchase than traditional diesel-engine buses ($750,000 per bus compared to $435,000 per bus, respectively); however, they have a longer expected lifespan than diesel buses. BE buses also save fuel and maintenance costs. Proterra has stated that overall, the lifecycle costs of BE and diesel buses are similar. The PVTA estimates that each of its BE buses will save the agency $448,000 combined in fuel and maintenance costs. The PVTA also calculated that each of its BE buses will eliminate 244,000 pounds of carbon dioxide emissions compared to their diesel bus counterparts.

The second main type of zero-emissions buses are those powered by hydrogen fuel cell batteries. Fuel cell battery electric (FCBE) buses store hydrogen onboard in storage tanks and the hydrogen is then supplied to the fuel cells to generate electricity to power the vehicles. There are no emissions, as water is the only by-product for FCBEs. There are presently seven U.S. transit agencies operating FCBE buses; the electric bus at the Massachusetts Bay Transportation Authority (MBTA) uses FCBE technology.

With a typical purchase price of $1.2 million, an FCBE bus is much more expensive to purchase than a conventional diesel bus ($435,000) or a compressed natural gas bus ($500,000). FCBE buses also require special training for bus operators on using the technology and special hydrogen storing and fueling facilities; these are typically located at bus depots to allow vehicles to be refueled at day’s end. On the plus side, the fuel economy for FCBE buses has been reported to be double that for compressed natural gas or diesel buses.

The third main type of zero emission buses are fuel cell hybrid (FCH) plug-in buses which use a combination of both onboard batteries and hydrogen fuel cells. To date, only 7 U.S. transit agencies have used FCH buses, mainly in short-term demonstration projects. Transit agencies that have tried FCH buses have consistently reported significant downtime for the buses, due to issues with the batteries, the fuel cell systems, and the hybrid integrator, and to challenges in diagnosing specific problems.

Currently, BE buses seem to hold the most promise for wider deployment and use.


Meet Our Affiliated Researcher: Dr. Amro Farid, Associate Professor at the Thayer School of Engineering, Dartmouth

Dr. Farid is an Associate Professor at the Thayer School of Engineering at Dartmouth and Director of the Laboratory for Intelligent Integrated Networks of Engineering Systems (LIINES). His research is devoted to enhancement of sustainability, and resilience in intelligent energy systems. His research team seeks to develop an internationally recognized, locally relevant and industrially-facing program of research that engineers intelligent & integrated control, automation, and information technology systems that support the operations and planning of large scale integrated energy systems. These activities encourage and facilitate technology policy that supports the achievement of energy, water, transportation & industrial policy objectives while eliminating barriers to sustainable and resilient automated solutions.

Within our electrified transportation systems research theme, the center has made two important achievements.

1.) Abu Dhabi Electric Vehicle Integration Study: In the first full scale study of its kind, the LIINES has studied the technical feasibility of electric vehicles with respect to three infrastructure systems: the road transportation system, the electrical grid, and the Abu Dhabi Department of Transportation’s Intelligent Transportation System. Acknowledgement: The LIINES is grateful to METI for its partial financial support of this research, Mitsubishi Heavy Industries for the use of its Clean Mobility Simulator software and the Abu Dhabi Department of Transport for providing data on its traffic patterns and intelligent transportation system.

2.) Hybrid Dynamics Modeling of the Transportation-Electricity Nexus: Building upon the previous research project and develops a hybrid dynamic system model of the full Energy-Transportation Nexus. By choosing to include the behavior of the transportation system in combination with the electrical system this model seeks to coordinate four types interdependent decisions: vehicle routing/dispatching, charging queue management, charging dispatch, and vehicle-2-grid stabilization.

Dr. Farid also maintains a research blog that highlights his latest conference proceedings, research and publications. His most recent publication is titled “A Hybrid Dynamic System Model for Multi-Modal Transportation Electrification,” published in the IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY.

For more information on Dr. Farid you can click here.  We at the UMTC are pleased to welcome him to our Affiliate Researcher Network and look forward to working with him on interesting transportation research ideas in the future.