Here’s an overly simplistic article that questions the validity of electric vehicles as “green” transportation, suggesting that charging EVs can require more coal to be burned. I note the comment: “I power my electric car totally from solar PV panels. This article should be citing coal-fired power plants, not electric cars.” He has an excellent point, but, since most EV drivers charge their cars from the grid, this too over-simplifies the matter.
Here are several items to consider, and I’m sure I’ve missed a few myself:
• To understand how clean the fuel is, the question is not: “What is the average grid-mix?” but rather, “Exactly what happens when I put additional load on the grid when I charge my car at night?” In the U.S. in 2012, that normally means someone somewhere will be burning more coal. And, to the degree that’s true, EVs are a terrible solution environmentally.
However, it’s more complicated and dynamic than that, as:
• When charged during the day, you’re more likely to be causing more gas-fired peaker plants to be in operation. Obviously, gas is far cleaner (about half the CO2, and almost none of the toxins in coal). But what about the cost of building and operating new plants?
• The guy who commented above isn’t alone, lots of people charge their cars with PV, which all but eliminates the ecologic cost of the fuel. Moreover, these folks are being joined by an increasing number of eco-conscious consumers every day
• More EVs charging at night will enable more wind at night: more construction of wind farms, better pricing for off-peak wind energy, and less curtailment.
• There is also a growing trend towards distributed wind, and this is a great fit for EVs. I’ve written about my friends at Continental Wind Power with their 400 kV “midsized wind” solution. We can all imagine, for instance, a farm that powers not only its irrigation pumps but also charges its electric farm equipment, without a single electron coming from the grid.
• More EVs will eventually add strength to the smart-grid initiative, including V2G (vehicle to grid). At stake here is not so much the power that be taken from EVs as they’re parked and out of use, but “ancillary services” like frequency regulation.
• Consumer adoption is hampered by an unattractive value proposition, largely a function of the price and energy density of batteries. Of course, this is changing continuously for the better.
• There are materials issues that need to be considered. With a growing and increasingly urbanized population, there will be fierce international competition for non-ferrous metals.
• There are dozens of scary, unpredictable issues concerning the scarcity of oil.
So, what do you get when you add all up? Obviously, it’s hard to know exactly. Overall, I remain bullish on the subject.