A team from the National Renewable Energy Laboratory (NREL) and the Idaho National Laboratory has produced a detailed assessment of the current levelized cost of light-duty electric-vehicle charging (LCOC) in the United States, considering when, where, and how EVs are charged.

The LCOC includes costs associated with the purchase and installation of charging equipment and retail electricity prices, derived from real-world utility tariffs. The analysis is published in the journal Joule.

The researchers found that under the baseline scenario, the current national average LCOC in the United States is $0.15/kWh for light-duty BEVs and $0.14/kWh for light-duty PHEVs. For BEVs, this assumes a charging mix of 81% residential, 14% workplace/public L2, and 5% DCFC, and that 84% of residential charging uses L2 EVSE.

The levelized cost of charging includes costs associated with the purchase and installation of charging equipment and real-world electricity prices. Borlaugh et al.

For PHEVs, this assumes a charging mix of 81% residential and 19% workplace/public L2 and that 50% of residential charging uses L2 EVSE. These LCOC values are similar to the average residential cost of electricity reported by EIA ($0.13/kWh); however, costs vary considerably (e.g., from $0.08/kWh to $0.27/kWh for battery EVs) for different charging behaviors and equipment costs.

Sensitivity of LCOC for US BEVs to charging site mix, vehicle use, utility tariffs, and equipment costs. Borlaugh et al.

This corresponds to a total projected fuel cost savings between $3,000 and $10,500 compared with gasoline vehicles over a 15-year time horizon). Regional heterogeneities and uncertainty on lifetime vehicle use and future fuel prices produce even greater variations, the researchers said.

The cost to charge an EV (i.e., the EV “fuel” cost) depends on many factors, including the retail price of electricity, capital cost of charging or electric vehicle supply equipment (EVSE), the cost of installation and maintenance of this equipment, and, for dedicated charging stations, additional business and operational expenses. Each factor is further dependent on the type of EVSE used—AC Level 1 (L1), AC Level 2 (L2), or DC Fast Charging (DCFC), charging site—home residence, workplace, or public station, charging profile, and geographic region.

This complexity produces a wide range of possible EV charging costs. Despite this, many studies assume the cost of EV charging to be equivalent to the average residential cost of electricity (often the price reported by the US Energy Information Administration (EIA)) or the average levelized cost of electricity generation. These simple assumptions fail to capture important variations in the cost of EV charging associated with the factors described previously.

—Borlaug et al.

Resources

• Borlaug et al. (2020) “Levelized Cost of Charging Electric Vehicles in the United States,” Joule doi: 10.1016/j.joule.2020.05.013