Date of Graduation

Spring 5-16-2014

Document Access

Project/Capstone - Global access

Degree Name

Master of Science in Environmental Management (MSEM)


Environmental Management

First Advisor

Maggie Winslow


Greenhouse gas (GHG) emissions from anthropogenic sources are the leading contributors to global climate change. Over the past century, GHG emissions have increased tremendously due to causes such as deforestation and the burning of fossil fuels. In the US, about 28% of these GHG emissions come from the transportation sector. By replacing conventional gasoline powered vehicles with plug-in hybrid (PHEV) and battery electric (BEV) vehicles, the amount of GHG emissions released can be reduced significantly.

In order to make the transition to alternative fueled vehicle, consumers must be informed on the economic and environmental consequences of purchasing one. This paper compares PHEVs and BEVs for both GHGs and costs. By comparing the results of a lifecycle GHG analyses of PHEVs done by Samaras and Meisterling with one done on BEVs by Aguirre et al., this paper found that BEVs produce about 4,000 kg fewer lifecycle GHG emissions than PHEVs over the life of the vehicles, using the US average electricity grid mix. Additionally, a lifecycle cost comparison was done to calculate the payback periods of PHEVs and BEVs when compared to a conventional gasoline vehicle. The analysis showed that the BEV has the lowest lifetime costs due to its increased fuel and maintenance cost savings. With the $7,500 Federal tax credit, the payback period of the BEV will only be about four months, as opposed to 2-9 years for a PHEV, depending on the specific model purchased.

It should be noted that the GHG emissions associated with charging PHEVs and BEVs is completely dependent on the local electricity grid mix. In highly carbon-intensive areas, it may be possible to generate more GHG emissions by operating a BEV than a conventional gasoline car. Because of this, policy makers need to focus on implementing measures such as carbon-cap programs or clean energy initiatives in order to lower nationwide GHG emissions. By coupling these strategies with increased incentives for alternative fueled vehicles, it is possible to see a significant reduction in GHG emissions from the transportation sector.