Friday, March 27, 2015

Question Of The Month - March

Question of the Month: What are the key terms and considerations I should remember when discussing emissions?

Answer: When discussing emissions, it is important to use the appropriate terms, know the context, and present a complete picture. The U.S. Department of Energy (DOE) has a number of tools and resources available to understand and calculate the emissions benefits of alternative fuels and vehicles (see below). But first, let's get back to the basics.

Criteria Pollutants versus Non-Criteria Pollutants
Vehicles emit both criteria pollutants and non-criteria pollutants. In compliance with the Clean Air Act, the U.S. Environmental Protection Agency (EPA) classifies six common pollutants as criteria pollutants based on certain health and environmental standards:
  • Carbon monoxide (CO)
  • Oxides of nitrogen (NOx)
  • Particulate matter (PM)
  • Ozone
  • Oxides of sulfur (SOx)
  • Lead

For more information about criteria pollutant emissions, refer to the EPA Six Common Air Pollutants page.

Greenhouse gases (GHGs), including carbon dioxide, are considered non-criteria pollutants. The following also fall into this category:
  • Volatile organic compounds (VOCs)
  • Total hydrocarbons (HCs)
  • Methane
  • Air toxics
  • Other organic gases

For more information about GHG emissions, refer to the EPA Overview of GHGs page.

Measuring Emissions
You can evaluate vehicle emissions through a number of lenses. Considering emissions in different contexts can present a more impactful picture, depending on the stakeholder.
  • Life cycle emissions: Emissions generated through all stages of a fuel's life, including raw material extraction, processing, manufacturing, distribution, use, and disposal or recycling. Life cycle emissions are typically considered when evaluating "global pollutants," or pollutants that have an impact regardless of where they are emitted. For example, GHGs are usually measured on a life cycle basis.
  • Tailpipe emissions: Emissions directly from the exhaust of the vehicle. Tailpipe emissions are considered when looking at "local pollutants," or pollutants that impact air quality directly where they are emitted. For example, criteria pollutants, such as PM, are typically measured as tailpipe emissions.
  • Evaporative emissions: Emissions from the vehicle's fuel system and during the fueling process, not including the combustion of the fuel. Evaporative emissions are also considered when evaluating "local pollutants."

When quantifying or presenting emissions benefits for a particular project, make sure to ask yourself which type of information would have the most impact. For example, an air quality organization (e.g., your local American Lung Association chapter) would like to hear about tailpipe and evaporative emissions. A national company focused on their footprint and impact on climate change would want to hear about life cycle emissions.

Emissions Standards
EPA sets tailpipe and evaporative emissions standards for new vehicles.

The California Air Resources Board (CARB) enforces vehicle emissions standards for California that are more stringent than federal EPA standards. Vehicles may be certified as compliant with federal standards, CARB standards, or both. For information on CARB's emissions standards, visit the Mobile Source Program Portal. Several other states have chosen to comply with certain CARB standards as well, so read up on the requirements in your state. See the AFDC Laws & Incentives website for more information.

Other Considerations
It is important to take into account the "full package" when looking at alternative fuel vehicle (AFV) emissions; again, try to anticipate questions from the audience to tease out the most relevant information. For example, keep the following in mind:
  • While a fuel may not offer large reductions in one pollutant, it may offer significant benefits in other pollutants.
  • Emissions information should also be presented in the larger context of federal and state regulations.
  • Be sure you are comparing "apples to apples" when looking at AFV and conventional vehicle emissions. For instance, look at which pollutants are covered, and whether tailpipe, life cycle, and/or evaporative emissions are being measured. Every study is different, so it can be very difficult to compare outcomes of one to outcomes of another.

Emissions Analysis Tools
With all of that in mind, the following tools can be used to calculate fleet emissions and plan for overall emission reductions:

Clean Cities Technical Response Service Team

Sunday, March 15, 2015

The Effect Of Energy Prices

As diesel prices drop, fleet managers think twice about converting to CNG or LNG.
In fact, diesel and natural gas should both be part of a longer view of a policy of fuel diversification.

Many companies committed to natural gas vehicle deployment realize long-term economic and environmental benefits. U.S. production of natural gas is rising, as new sources are discovered and recovered nationwide. It’s widely available in both local and over the road markets. Product innovation means alternative fuel sources for commercial transportation, from the light- to medium-duty market or an entire portfolio, including passenger, light, medium and heavy commercial use, are finding their place beside traditional fuel sources.

Friday, March 13, 2015

Vehicle Emissions Connected To Impaired Learning Skills

A year-long study of 3,000 children, ages 7 to 10, in Barcelona showed a correlation between high levels of elemental carbon, nitrogen dioxide, and particulates and a lag in three areas of cognitive development. The study suggests "'that the developing brain may be vulnerable to traffic-related air pollution well into middle childhood,' not just before birth or during the infant years." Elemental carbon, nitrogen dioxide, and particulates are extremely small bits of burned hydrocarbons created by burning oil, gasoline, and diesel fuel.

The article in which they published their findings (in English) can be found here.

Oklahoma Regulation Of Oil And Gas Wells

Monica Trauzzi of The Cutting Edge interviews EnergyWire reporter Mike Soraghan on the subject of the increased number of earthquakes in Oklahoma. The state is taking a closer look at regulating disposal wells, which are not hydraulic fracturing wells. A video of the interview can be found here.

Sunday, March 1, 2015

Fueling the Future with Natural Gas

Natural gas as a transportation fuel is not a new story. While it is often the energy source for generating electricity and heating homes, vehicles have been operating on this fuel for quite some time too. Did you know one of every five transit buses in America is fueled by natural gas? It's no wonder more and more fleets are discovering the advantages of going green with this advanced, cost-effective, sustainable solution. With over 14.8 million natural gas vehicles on the roads worldwide, its growing acceptance is rapidly changing perceptions. See the infographic below to explore the benefits of a cleaner, more efficient means of powering North America's commercial transportation.

Natural Gas Infographic

Wednesday, February 25, 2015

State Laws and Incentives Trends of 2014

Question of the Month: What were the trends related to state laws and incentives enacted in 2014?

Answer: In 2014, state legislatures and agencies developed a variety of incentives, laws, and regulations that support the use of alternative fuels, advanced vehicles, and other strategies that align with Clean Cities' mission to cut the amount of petroleum used in transportation. As compared to 2013, however, the number of newly adopted state laws and incentives decreased, possibly indicating the effectiveness of existing state programs and a maturing alternative fuels market. In addition, several states worked to fine-tune existing programs this past year, in an effort to find the best market penetration strategy.

The majority of state actions across all alternative fuel types in 2014 involved new tax-related incentives and fuel tax regulations. Specific alternative fuels displayed their own trends as well. Laws and incentives related to the following vehicle categories showed particularly notable trends:

Plug-in electric vehicles (PEVs), including both all-electric and plug-in hybrid electric vehicles, and the associated charging infrastructure were the most popular alternative fuel technologies that received attention in the form of new state laws and incentives in 2014. States worked to streamline many aspects of PEV ownership, including allowing direct purchase of PEVs from a manufacturer, modifying rebates and incentives for electric vehicle supply equipment (EVSE), and allowing EVSE at previously restricted locations, such as state facilities and leased properties. A few states initiated studies to determine how to assess PEV owners a supplemental fee in lieu of the gasoline tax they would no longer be paying. Utilities continued to provide new incentives in 2014, including electricity rate discounts for customers using EVSE.

Natural gas vehicles (NGVs) continued to draw significant consideration in 2014, particularly in those states following the national trend of basing a compressed natural gas (CNG) motor fuel tax on the favorable gasoline gallon equivalent conversion. The NGV market and consumers will also benefit from grants, weight exemptions, fuel-training programs, and fleet requirements enacted in the last year.

The Alternative Fuels Data Center's (AFDC) State Alternative Fuel and Advanced Vehicle Laws and Incentives: 2014 Year in Review provides a further synopsis of incentives and laws enacted in 2014 and is available at

In addition, the AFDC Laws & Incentives website provides a searchable database to identify and view relevant state laws and incentives by fuel type, as well as by variety of incentive or regulation. As legislative and gubernatorial actions occur, follow the AFDC website for updates at This database may be particularly useful in the states in which the 2014 elections changed control of the legislative or executive branches. In addition, as the 2014 tax filing deadline approaches, the Laws & Incentives website is a valuable resource for basic information regarding new or expiring state and federal tax credits.

As new trends and issues emerge from legislation, policy bulletins are posted to the AFDC Technology and Policy Bulletins page. You may submit new or updated state laws and incentives, and suggestions for policy bulletin topics, by emailing the TRS directly at

Friday, February 6, 2015

The Benefits And Challenges Of Natural Gas Conversion

Here's an interview with Erik Neandross who "has constructed conversion programs for some of the nation's largest private fleets, as well as for the city of Los Angeles."
Q: What do private fleets need to understand about the economics of conversion before exploring such a move? Are there metrics or benchmarks they need to meet before determining this is right for them?

A: Regardless of which fuel you choose, NGVs (natural gas vehicles) have a significant capital cost compared with diesel-powered vehicles. The incremental cost needs to be paid back through lower fuel costs. Each fleet must look at how much fuel it burns per vehicle to determine if the savings will cover the incremental cost of the vehicles in an acceptable timeframe. Some heavy-duty fleets simply don't use enough fuel per vehicle to meet their own investment hurdle rates. They will have a difficult time making the switch.