How Public Fleets Use Electric Vehicles to Meet Emissions Targets

 In Fleet Sustainability

Earlier this summer, President Donald Trump announced that the United States will pull out of the historic Paris Climate Accord, receiving widespread international condemnation, both from climate activists and heads of state. While the ramifications of the announcement as it relates to official policy remain unclear, the work of meeting climate commitments was always intended to be a shared effort between cities, counties, states and the federal government, as well as partners in the private sector. So far, there is little indication Trump’s public rejection of the accord has weakened the resolve of the thousands of elected leaders and administrators already working to slash greenhouse gas emissions in line with future targets.

Part of this effort involves “greening” the operation of government itself, which in cities like Atlanta contribute upwards of 5.5 percent of the total emissions footprint. Atlanta has set goals of reducing municipal operations emissions 20 percent by 2020, 40 percent by 2030, and 80 percent by 2050. Similar efforts are underway at city and state agencies all over the country, with administrators and managers facing pressure to seek potential areas for emissions reductions wherever they can be found.

Greening Public Vehicle Fleets

Though few of us might notice it, government vehicles are all around us on the road—sending more combined transportation-related pollutants into the air than any individual private entity. In New York City, public fleets total more than 29,000 vehicles, contributing nearly 4 percent of the city’s total annual on-road emissions output. New York is currently working to reduce its emissions footprint to 50 percent of 2005 levels, in part by adding 2,000 plug-in electric vehicles to its fleets.

The Big Apple is just one of thirty cities around the U.S. that have joined forces in a group purchasing pact that will use its combined leverage to negotiate better prices from manufacturers on as many as 114,000 vehicles in the coming years. (For context, the total plug-in market in the U.S. was roughly 160,000 units in 2016.)

The impact of these acquisitions won’t be insignificant. New York expects the 2,000 newly-purchased EVs and PHEVs to reduce gasoline consumption by 2.5 million gallons and GHG emissions by as much as 9 percent by 2025. While that represents just a tiny sliver of the 80-percent reduction in total emissions the city is targeting by 2050, it’s likely just the first step in a long-term effort to replace petroleum as an energy source for New York municipal vehicles.

Fleet Size Matters

New York’s 2,000-vehicle commitment to plug-ins places it at the forefront of municipal public fleet plug-in adoption in the U.S. But even with a total of 29,000 city-owned vehicles on its roads, New York had to be careful in selecting which vehicles can suitably be replaced by plug-ins. Due to the current limitations and trade-offs of existing electric vehicles—be they price, performance, range or size—many gas-fueled vehicles simply aren’t yet practical targets for replacement.

With time though, battery technology will improve, prices will lower, a wider variety of plug-in models will become available and the portion of replaceable vehicles will grow. For entities with massive fleets like New York, these kinds of initial investments in plug-ins will pay the biggest emissions dividends down the road. Eventually, even more demanding applications like police cars, buses, and repair trucks will be cost-effective targets for replacement by electric drivetrains—and as more renewables enter the energy mix, fleets will be able to reap increasing emissions savings as they expand their investments.

For entities with smaller fleets, the long-term outlook may not be as significant, but replacing internal combustion vehicles with plug-ins could still represent a cheaper, more immediate source of emissions reductions than replacing or upgrading larger contributors such as city buildings. Each entity will be unique in how it can best prioritize investments in meeting GHG reductions, but effectively calculating transportation emissions—both before and after a potential investment in cleaner cars—should be a central area of consideration for policymakers, administrators and fleet managers alike.

A localized assessment of emissions factors is necessary to model GHG reductions.

Calculating the Emissions Benefit of Fleet Plug-in Adoption

Though it’s easy enough to say that replacing an internal combustion engine (ICE) vehicle with an all-electric model will save 100% of emissions from gasoline, that kind of reductive understanding isn’t of much use in meeting emissions targets. A comprehensive accounting of emissions must determine each of the following:

1. The number of miles the ICE vehicle that is being considered for replacement travels each year 

Mileage data logging—whether executed through sophisticated telematics systems or by simple odometer checks—is already a widespread best practice for fleets regardless of fuel source. So calculating the annual mileage of outgoing vehicles should be simple enough for most fleet managers.

2. Total annual carbon emissions from outgoing gas vehicles

Multiply the annual mileage of a vehicle by the model’s EPA-estimated carbon emissions rating (expressed in grams of Co2 / mile). This can be found using the EPA’s vehicle database.

3. The emissions factor of energy sources generating the electricity to power EVs

Calculating the emissions associated with electricity generation to power plug-in vehicles can be a bit tricky. Different electricity markets vary widely in the balance of their energy source portfolios. Emissions from these different sources range from almost zero in renewables like solar and wind power to the higher concentrations released from petroleum or coal-fired generation.

To calculate the emissions footprint of a plug-in, you must first know the emissions factor of the electricity it uses, which is expressed as Pounds of CO2 / MWh. This information will most likely be available on your utility’s website. State-by-state average emissions factors (which don’t necessarily reflect the specific energy balance of your utility) are also listed by the U.S. Energy Information Administration.

4. An estimate of how many electric miles a plug-in acquisition would travel

Determine how much electricity your plug-in uses or will use. Telematics products like FleetCarma can track the duty cycles and energy usage of both plug-ins and conventional ICEs. If you know how far your current gasoline vehicle travels each year, you can get a rough estimate of how much electricity an all-electric replacement might use by multiplying the number of miles it will travel by the plug-in’s energy efficiency, which can be found at, expressed as kWh / 100 miles.

Plug-in hybrids are a bit trickier. To estimate the average annual emissions from a plug-in hybrid, you must first determine how often it goes beyond its fully-charged electric range in a given day. With telematics tracking, fleet managers can determine the frequency of days that a Chevy Volt would travel outside of its 53-mile electric range and then project the total number of miles of gas-powered miles it would require. These estimates will be rough, but they increase in accuracy with a larger data sample.

5. A final projection of potential annual emissions reduction from plug-in acquisition based on the above factors

Subtract the annual emissions estimate for potential plug-in acquisitions from the output of the vehicles they will be replacing. You may want to do multiple emissions comparisons for different plug-in models in order to determine the most practical, cost-effective investment options.

FleetCarma’s Electric Vehicle Suitability Assessment projects a number of factors including cost and emissions reductions.

FleetCarma’s Electric Vehicle Suitability Assessment streamlines this entire process and even provides a side-by-side comparison of the plug-in models that best suit the needs of a fleet. What’s more, FleetCarma’s estimates are localized to reflect the energy costs and emissions values of your electrical utility provider.

For some entities, a simple, standardized methodology may already be in place to calculate emissions compliance from vehicle replacement. While such methodologies may not better reflect the real world duty cycles of a particular vehicle or fleet, they’re the ones that will ultimately matter from a compliance standpoint.

Looking Forward

Regardless of the current American president’s personal commitment to fighting climate change, the work of meeting the long-term GHG emissions reduction targets of commitments like the Paris Climate Accord will continue for decades after he has left office. The efforts taken by public fleets in these early years to prepare for mass vehicle electrification down the road will be crucial to smoothing the transition as emissions targets quickly escalate over the coming decades. Gathering data, exploring solutions and implementing pilot EV programs now are necessary first steps towards one day freeing a fleet from its dependence on fossil fuels.

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