Tesla, EV Charging, and CO2 Emissions

Posted in Uncategorized by Ryan on the December 4th, 2015

Saw Tesla share this post about a ticket for blocking an EV charging spot.

Warning to gasoline car drivers, if you block an EV charging station in Gaithersburg in Montgomery County, Maryland with a vehicle that doesn’t plug-in, you risk getting a $60 parking fine. The police in Gaithersburg gave a ticket to a Jeep that parked in a clearly marked electric vehicle charging spot at the Cadence at Crown parking garage.

While I’m a fan of Tesla and electric cars in general, it can get rather interesting when you crunch some numbers. Depending on the type of vehicle parked in the EV charging spot, you may be doing the earth a favor if you block an electric vehicle. Assuming of course that you accept CO2 emissions are contributing to harmful climate change.

See, electricity doesn’t come from no where, it must be generated, and when you research the power company providing the juice, you can estimate the CO2 footprint of an electric vehicle across the same 15,000 miles uses to estimate CO2 emissions.

PEPCO, which provides power in Gaithersburg, Maryland, provides the emission estimates for their power generation given their fuel mix averaged over a previous period of months. Here is their latest information for  July 2014 – June 2015.

Screen Shot 2015-12-04 at 11.53.40 AMScreen Shot 2015-12-04 at 11.53.30 AM

So, doing some informal number crunching, given 15,000 miles a year and extrapolating Tesla’s 70kWh model with a range of 240 miles, and a Tesla would generate 4.6 tons of CO2 annually plugged into a PEPCO power source. So, it beats this Jeep (probably any Jeep, I just picked a generic 4WD 2014 Wrangler), which would emit 8 tons annually.

My 2005 Escape Hybrid, however,  is cleaner than the Jeep at 5.1 tons annually. But it still falls short of the Tesla’s 4.6 tons. But that is a 2005 1st generation small SUV hybrid. Let’s compare a current model hybrid sedan, like the Ford Fusion Hybrid or the MKZ Hybrid. Those vehicles are actually cleaner than a Tesla plugging into PEPCO power, emitting 3.5 and 3.7 tons compared to Tesla’s 4.6.

Screen Shot 2015-12-04 at 11.59.45 AM

Interesting food for thought about where you plug in an electric vehicle and the fuel mix where the electricity actually comes from. So, next time you’re in a jam trying to find a parking spot, if you drive a current model hybrid and the EV charging spot is open, go ahead and park there for the sake of the oceans and the children.

EDIT: Revisiting this, I think I made an error in comparing tons and pounds, mistaking a ton for 1000 pounds and not 2000. Doh. So, the Tesla actually produces half of the CO2 I estimated at 2.3 or so. I think comparing a Fusion Hybrid to it is still noteworthy, 3.5 vs 2.3, but the Tesla does have it beat. As power companies evolve their fuel mixes away from coal, the CO2 footprint per megawatt will continue to decline.