There has been some press lately calling into question the actual carbon footprint of operating a battery electric vehicle (BEV). There is logic behind this. Utilities quite commonly generate carbon emissions from their portfolio of generation sources, whether natural gas driven turbines or coal plants. They (the investor owned utilities like PGE or PacifiCorps) are obligated as regulated monopolies to provide power on demand to our society, no matter that demand’s daily and seasonal peaks and troughs. As a result they have devised an ingenious system that includes baseload power generation sources (those which can economically and reliably provide most of our power needs, day in, day out) and peaking plants to cover exceptional power needs. The source of this baseload power is highly dependent on the region served. The Southeast and Northeast have had little historic choice but to rely on fossil fuels, such as coal and natural gas, to feed their demand. They lack cheap, natural resources. The Northwest has the happy fate of enjoying a deep bench of low or zero emission generation sources starting with the Columbia River Basin Hydro-system (which generates almost 50% of the region’s power depending on snowpack) and extending out into the Gorge through Sherman and Morrow Counties where currently 2300 mWh of wind generation (valued at $4.5b) has been installed.
So how do you respond when someone says an EV’s electrical use is not “clean”?
First, zero emission vehicles are simply defined as emitting no combustion byproducts from their tailpipe. At this level, and it is a reasonable level, all BEVs qualify as zero emission. In congested, urban settings, preventing the introduction of additional emissions has tangible environmental and health benefits. Of course, the argument then turns to the generation source of electricity, often located far away from the urban centers who benefit most from the generation, and whether that contributes CO2 emission and merely displaces its impact to rural settings. An analysis requires each EV owner to be familiar with the source of his/her region’s baseload electrical generation (which you should be able to get directly from your electricity provider.)
“Even in the worst-case scenario where 100 percent of that generation is from coal, there is still a net positive emissions trade-off,” Glenn Stancil of NRG Energy VP said. A 2007 study found that a plug-in hybrid electric vehicle charged with electricity from a coal plant would result in 25 percent less carbon dioxide emissions than a conventional gasoline vehicle, he said. The study was conducted by Electrification Coalition, a trade group of which NRG is a member.
It bears noting that EVs are much more efficient in converting energy to movement compared to their gas counterparts, which means they still create less carbon emissions per mile. In that sense, even if we kept coal and natural gas electric generating plants, and added to them, as a country we would still experience a net decline in carbon emissions if our light-duty/passenger fleet converted over entirely to BEVs.
We can do better. In the Pacific Northwest we have the unique ability to charge our BEVs with truly clean electric power. Portland General Electric sponsors its Green Source Program, which adds 1.2 cents per kWh on my monthly bill. For this, I receive a 100% renewable energy mix ranging from low-impact hydro, to wind to geothermal.
Zero can truly mean zero.