Study Supports Green Credentials of EVs, PHEVs

Claims that electric vehicles and other environment-friendly vehicles do not significantly reduce toxic emissions have been debunked by a recent study. The study which was conducted by Michael Sivak and Brandon Schoettle of Michigan University’s Transportation Research Institute seems to confirm that EVs can make a significant difference when it comes to reducing the pollution caused by vehicles on a daily basis.

The study took into account both the sources and production of electricity and the fuel used in internal-combustion engines and found that EVs are considerably cleaner than vehicles with conventional powertrains. The researchers found that the greenhouse-gas emissions for battery-electric vehicles (BEVs) is the lowest, at 214 grams per mile while the corresponding values for two different plug-in electric vehicle implementations, PHEV10 and PHEV40, range from 253 to 278 gpm, respectively. In the case of gasoline-powered vehicles which produce the highest level of greenhouse emissions per mile, this went up drastically and ranged from 356 to 409 gpm. The exact level depended on the specific type of engine used such as direct-fuel-injection or conventional port-fuel injection.

According to Schoettle and Sivak, the results of the GREET (Greenhouse Gases, Regulated Emissions and Energy Use in Transportation Model devised by the Argonne National Laboratory) model indicated that a typical BEV emits approximately half the amount of GHGs as a typical fuel-injected ICE (Internal Combustion Engines).

The researchers in Michigan found that EVs are not only cleaner but are also more efficient than ICE vehicles. They wrote that BEVs (battery electric vehicles) use the least amount of petroleum at 54 Btu/mile, while a typical PHEV40 vehicle model came second in usage at 1,588 Btu/mile and a typical PHEV10 vehicle model used the third-lowest amount at 2,588 Btu/mile.

A study conducted by the European Environment Agency had estimated that battery-electric vehicles’ greenhouse-gas emissions could be reduced by a factor of 10 if completely renewable power sources were used.

The EEA report stated that when total well-to-wheels petroleum usage is compared in British thermal units (Btus), (PHEV) types fared better than versus conventional ICE vehicles.

The UMTRI researchers said that gasoline-powered vehicles use considerably more petroleum per mile. Direct-fuel-injection ICEs averaged 3,791 Btu/mile and traditional fuel-injection ICEs averaged 4,359 Btu/mile. In the case of PHEVs, while the PHEV40 consumed 29 times the amount of petroleum a typical BEV consumes, a conventional fuel-injected ICE still consumes almost three times as much petroleum as a PHEV40 and about 80 times more petroleum than a BEV.

According to Sivak Schoettle, some of the main barriers to large-scale adoption of BEVs and PHEVs are limited range, long charging times and higher sticker prices for EVs. This has however begun to change in recent years and sales of both BEVs and PHEVs have begun to increase to the tune of more than 700% since 2011. The number of available models has also increased, nearly doubling from model year 2016 to 2017, while prices gradually are slowly dropping to levels similar to that of conventional cars.

“Recent improvements in range and charging times for both vehicle types move closer to wider acceptance based on the ability to satisfy the daily driving requirements of most drivers while lessening the overall range anxiety that plagued PEVs (particularly BEVs) when first introduced,” Sivak and Schoettle write.

One practical solution they have suggested in their report is the integration of solar-powered stations to supply electricity directly to the ESVEs (electric vehicle supply equipment) within a specific charging station or location. Battery costs for BEVs are coming down while battery performance is improving. Charging infrastructure, even in the Middle East and especially in Dubai is expanding. Another benefit of EVs is that while petroleum prices are highly volatile, the price of electricity is relatively stable.