At the Sedona City Council priority retreat on Jan. 18 and 19, council members and staff renewed their commitment to pursuing green energy policies, in particular by encouraging the use of electric vehicles through the provision of chargers and by replacing city vehicles with electric models.

The city’s recently-departed sustainability coordinator Alicia Peck announced that the city has entered a partnership with the APS utility to source all of its energy for municipal operations from renewable sources, becoming the second participant in the program after Flagstaff.

Peck also mentioned that the city was considering a proposal for decarbonization of municipal buildings, that staff have selected new software to help with greenhouse gas accounting and that “our home energy retrofit project is still alive and well,” although there is no one on the waitlist for it. In the coming fiscal year, staff intend to “try to incorporate some [sustainability] standards into our procurement practices” as well.

Peck called attention to the fact that the city’s Climate Action Plan is scheduled to be updated this year, as is the city’s sustainability plan. “I don’t think a lot of people are aware that we’re doing this,” she said.

Greening the Fleet

The main focus of the council’s green energy discussion, however, was electrification of the city’s fleet and how to encourage the adoption of electric vehicles by residents.

“The message that we had heard from council is that as a governing body, you are committed to us moving in the direction to electrify our fleet and getting a different propulsion system over time, in as ambitious a fashion as we can,” City Manager Karen Osburn summarized.

The city’s current fleet consists of approximately 80 vehicles, not including maintenance vehicles. The non-electric vehicles in the fleet will be replaced with electric vehicles when they are due for rotation.

“Sometimes markets have to be driven, and need has to be created,” Councilwoman Kathy Kinsella said, arguing that transitioning to an electric fleet will make the city a market driver and set an example for others.

The city is pursuing this goal in part with its recent order for six e-bikes “to create a fleet of bikes for city staff to use in between buildings and meetings and stuff, to cut down on the use of vehicles,” Peck explained. “We are anticipating those being delivered between February and March this year.”

The city also plans to electrify its transit operations.

“The future transit maintenance and operations center is supposed to be sited next to the wastewater treatment plant,” city Transit Manager Robert Weber said. He informed the council that city staff aims “to design and engineer the facility so that it is pre-planned and ready for battery-electric, charging stations, et cetera. Potentially utilizing what’s called a micro-grid by tapping into the current solar facility which is adjacent to this property. As we understand, that facility’s under-utilized. It’s owned by a private firm … we want to figure out a way to tie into that to help support this facility and to support future transit operations for batteryelectric vehicles.”

At present, the sustainability staff is attempting to create an EV charging infrastructure plan for the city and public to further this objective. Peck explained that it could be either a threeyear or a five-year plan.

“We’d like to have a goal that we work toward of an optimum number of EV chargers for the time being,” she said.

“We need to install fleet-facing EV chargers if we are going to convert to EVs,” Peck continued. “We need to decide where to put those chargers. Once they are installed, it is very unlikely they will be able to be removed.”

With regard to the possibility of installing fleet chargers at city hall, she noted it would be necessary to choose locations for chargers “where we can prevent the public from parking in those spots and using those chargers when we need them for our fleet.”

The city has so far installed public chargers at the Jordan Road Uptown parking lot and Posse Grounds Park and is working on adding another charging station at Sunset Park. All have been installed for free through a partnership with APS. Chargers had also been planned for the Uptown parking garage, but with the garage project on hold, the city is uncertain whether those will have to be installed at another location or simply delayed.

Transportation Physics

How much of an emissions reduction do electric vehicles achieve?

While calculating lifecycle emissions for a vehicle is highly variable, an analysis by Carbon Brief found that a Nissan Leaf had expected emissions of 65 grams of CO2 per kilometer driven attributable to the fuel cycle and 27 g/km attributable to battery manufacturing, compared to 28 g/km and 3 g/km, respectively, for a Toyota Prius Eco. The Prius, however, had added direct emissions of 99 g/km due to running on fossil fuel.

Both vehicles were estimated to add 38 g/km of emissions resulting from the manufacturing process of the non-battery parts of the vehicle, for totals of 130 g/km and 168 g/km, respectively. A Tesla 3 has expected total emissions of 127 g/km, while the average non-electric car considered in the analysis had estimated lifecycle emissions of 258 g/km.

The emissions reduction for an electric vehicle could thus be anything from 23% to 50% depending on the bases of comparison. These figures are similar to those released by MIT and the U.S. Department of Energy.

Emissions savings are not synonymous with energy savings. The energy required to move a vehicle of a given mass a given distance is the same regardless of that vehicle’s energy source. As the Carbon Brief data shows, the emissions cost of the fuel cycle for electric vehicles is more than double that of fossil fuel vehicles due to conversion and other inefficiencies.

Conversely, a vehicle with significantly reduced mass will have reduced energy consumption and thereby reduced emissions regardless of its fuel source.

Most of the energy used to move an automobile is used to move the vehicle, not the passenger. Assuming an average passenger weight of 150 pounds, a 3,500-pound car like the Tesla 3 has a vehicle-to-passenger weight ratio of about 23:1 when carrying one passenger. Ninety-six percent of the energy expended when that car is in motion is not being used to move the passenger or accomplish useful work.

For comparison, a Sedona trailhead shuttle at 50% capacity has a V/P ratio of 9.7:1.

Approximate V/P ratios for other methods of transport technology are:

• Oasis-class cruise ship, fully loaded: 171:1
• Amtrak Superliner car, 60% capacity: 22.7:1
• Lightweight Tata Nano automobile, one passenger: 9:1
• Saddle horse: 7:1
• Cessna 172R, two passengers: 5.6:1
• Boeing 737-800, fully loaded: 3:1
• Ultralight aircraft: 1.7:1
• Vespa LX scooter: 1.6:1
• Jetson One single-passenger quadcopter: 1.3:1
• Cableway, 8 miles long, 1/2” cable, 100 passengers: 1.18:1
• Cycle rickshaw, 1 passenger: ~0.67:1
• E-bike: 0.2-0.5:1
• E-scooter: 0.17-0.33:1
• Conventional road bike: 0.13:1

These numbers suggest that reducing average vehicle weight by one quarter to one half, or replacing automobiles with other transport methods having a lower V/P ratio, will lower energy consumption and thus emissions as much or more than replacement of fossil fuel vehicles with electric vehicles.

It should also be noted that the above numbers for emissions do not take into account the emissions created by the construction and maintenance of the highway systems required by those vehicles. Horses, rickshaws and human-powered bikes are also carbon-neutral transport systems regardless of their V/P ratios.

Sedona’s Municipal Sustainability Plan, Climate Action Plan and Community Plan do not include any references to funding or encouraging the replacement of cars and buses with transportation systems that have lower V/P ratios, such as bikes, scooters, lightweight cars, rickshaws, quadcopters or cableways, apart from committing to add additional bike paths and increasing emissions in the process.