Published on November 3rd, 2016 | by James Ayre0
Electric Vehicle Use Reduces Greenhouse Gas Emissions Intensity 61% Or More In Minnesota
November 3rd, 2016 by James Ayre
Electric vehicle use in the state of Minnesota reduces greenhouse gas emissions (well-to-wheel carbon intensity) by at least 61%, according to a new analysis from the Great Plains Institute.
The 61% figure quoted above is with reference to Xcel Energy’s electric mix (in 2015). If the electric vehicle (EV) owner uses 100% renewable energy to recharge their vehicle (through Xcel’s Windsource program, a similar program, or their own PV power system), then this figure can be raised to 95% most of the time.
The findings are the result of the Great Plains Institute (GPI) using Argonne National Laboratory’s GREET Lifecycle Model to determine well-to-wheels carbon intensity in Minnesota under a number of different vehicle driving scenarios.
The GREET model collects and organizes the results of peer-reviewed science on GHG emissions and is considered to be one of the top “authorities on the measurement of GHGs.”
As indicated by the “lifecycle” term, the GREET model “includes exhaustive data on every aspect of energy production and use.” This includes data on fuel extraction, refinement, battery and vehicle manufacturing, fuel shipment and distribution, and automotive engine combustion.
Data on the specific energy situation in Minnesota was used by GPI as inputs to better determine the local picture for greenhouse gas intensity of internal combustion engine (ICE) and electric vehicle use in the state.
Here are some of the main findings:
“Gasoline vehicles in Minnesota emit an average of 465 grams of GHGs per mile (g/mile) when accounting for the full fuel lifecycle, which includes energy used for fuel extraction and refining. In comparison, full lifecycle accounting of an electric vehicle (EV) in Minnesota results in only 183 g/mile of GHGs on Xcel Energy’s 2015 fuel mix. It is interesting to note that because EVs have no tailpipe emissions, all emissions take place upstream, aka at the power plant and during vehicle manufacturing. And although it currently takes more energy to manufacture an electric vehicle and its battery than to build a gasoline automobile, as you can see in the above graph, the emissions from combusting gasoline vastly outweigh those from vehicle manufacturing.
“To calculate emissions outside of Xcel’s service territory, GPI used an average snapshot of electricity production on the Midcontinent Independent System Operator (MISO) system, which manages electric distribution across most of the Midwest. Because MISO includes many states that use a higher portion of fossil fuels than Minnesota, an EV that charges on the MISO grid would result in 268 g/mile GHGs, which still marks a 42% improvement over gasoline.”
A high percentage of EV owners utilize renewable energy programs offered by their utility — Xcel Energy’s Windsource and Great River Energy’s Wellspring being examples of such programs. A recent survey performed by GPI found that ~56% of regional EV owners take part in these sorts of renewable energy subscription programs. When doing so, EVs create an average of only 21 g/mile of greenhouse gas emissions — all of which relate to battery and vehicle manufacturing.
Going by the analysis findings, over an assumed vehicle lifespan of 160,000 miles, the average gas-powered vehicle would be responsible for around 76 tons of greenhouse gas emissions, the average EV would be responsible for somewhere around 29 tons of greenhouse gas emissions, and EV owners who recharge with 100% renewables would be responsible for only around 3.4 tons of greenhouse gas emissions.
An interesting but periphery finding of the analysis was that gasoline refined in Minnesota had an average carbon intensity around 10% higher than the US average, owing to the high proportion of product from the Alberta oil sands and the North Dakota shale oil fields.