Emissions by the numbers: Gas vs. hybrid vs. electric

Government support, directly correctly, can help propel a developing industry.

By Rolf Westgard

April 8, 2016 at 11:49PM
This undated photo provided by Tesla Motors shows the Model 3 car. The promise of an affordable electric car from Tesla Motors had hundreds of people lining up to reserve one. At a starting price of $35,000 ó before federal and state government incentives ó the Model 3 is less than half the cost of Tesla's previous models. (Tesla Motors via AP) ORG XMIT: MIN2016040118131750
Tesla Motors’s Model 3 car would cost less than half the price of the company’s previous models. (The Minnesota Star Tribune)

Tesla Motors has announced a quarter-million orders with cash deposits for its new Model 3 electric car. An average price of $40,000 with options could mean $10 billion in new revenue for Tesla.

A major argument for government-subsidized electric vehicles (EVs) is the reduction of greenhouse-gas carbon dioxide (CO2) emissions. It's worth comparing the emissions from the three major automobile types: standard internal combustion engine vehicles (ICEs), hybrids like the Prius and Ford Fusion, and the zero-emission EVs.

I'll assume 12,000 miles a year with a mix of winter/summer city and highway driving, and realistic data with radio and heater or air conditioner running. Today's average car and light truck will consume about 600 gasoline gallons a year, and will emit 11,000 pounds (5.5 tons) of CO2, or about 9/10ths pound of CO2 per mile. Hybrids get a little more than twice the miles per gallon of ICEs, so their emissions average 5,000 pounds a year, or 4.2/10ths pound of CO2 per mile.

The EVs don't emit while running, but they require emissions from the power plants that provide the electrons that charge their batteries. If the electron source is from non-emitting sources like nuclear, wind, hydro and solar, the EVs can be considered near-zero-emission. But those clean sources currently provide just a third of U.S. electric power demand.

Department of Energy figures tell us that the overall mix of the U.S. grid emits 1.4 pounds of CO2 per kilowatt hour delivered. Under all conditions with radio and AC, most EVs get about 3 to 3.5 miles per kilowatt hour. Based on Tesla ads, I will give the Tesla Model 3 four miles per kilowatt hour under those conditions. That equates to just 3.5/10ths pound of CO2 per mile. So driving a Model 3 results in a little lower CO2 emissions than driving a hybrid, and a saving of two-thirds the emissions from driving the conventional ICE.

Government-supported research has been important in supporting the growth of many of our major industries, including computers, aircraft, the Internet, nuclear power, renewable energy, pharmaceuticals, etc. In my opinion, the support was wasted on some premature large-scale programs such as with Solyndra solar, Range Fuels cellulose biofuels and the $2 billion Ivanpah concentrated solar farm in Nevada.

Tesla got a $465 million government loan plus other federal and state subsidies, and all EV buyers still get substantial EV stimulus funding. But this taxpayer funding may prove to be the kick-start for a new major American industry.

Rolf Westgard, of St. Paul, is a geologist who teaches classes on energy subjects for the University of Minnesota Lifelong Learning program.

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about the writer

Rolf Westgard

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