The Migration to Electric Transportation — It's Complicated
Here’s an overly simplistic article that questions the validity of electric vehicles as “green” transportation on the basis that coal is used to charge EVs. And here is one of the comments: “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:
• Many supporters of electric transportation point to the declining percentage of coal in our grid-mix. But 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 almost always means that someone somewhere will be burning more coal. And, to the degree that’s true, EVs are a terrible solution environmentally.
However, the situation is 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. 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 kW 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). This isn’t right around the corner, but will, I believe, represent an important ingredient in our energy future. At stake here is not so much the energy being taken from EVs while they’re parked, but rather their capacity to provide “ancillary services” like frequency regulation.
• Consumer adoption is hampered by a relatively unattractive value proposition, largely a function of the price and the energy density of batteries. As in any technology evolution (especially one that holds such huge profit potential), this is changing continuously for the better.
• There are materials issues that need to be considered. With a growing and increasingly urbanized world population, especially in Asia, there is bound to be fierce international competition for non-ferrous metals.
• There are dozens of scary, unpredictable issues concerning the scarcity of oil, almost all of which militate toward higher prices in the future.
So, what do you get when you add all this up? Obviously, it’s hard to know exactly. Overall, I remain bullish on the subject. And, since this is clearly the direction of the future, I’m happy to see that we’re heading there now.
I think trends are what are important. EV’s tend to charge off hours because it is convenient and also due to time of day billing. Ultimately, all large electric utilities will be doing TOD if they aren’t already.
Peaking plants are very expensive per kW. Night time charging is well down into the base load coverage regardless of what type of plant it is.
States like California are increasing their percentage of alternative energies in their base load, so it gets better every single year.
Policy to curb the use of coal and increase the use of gas is hard fought, but ultimately the right thing to do. The only truly ‘clean coal’ is a gasification process that doesn’t actually burn the coal and it allows sequestration of the CO2.
Energy storage at utility scale is slowly happening now that some people have invented technology that is lower cost than a gas peaking plant. Like policy, its a long slow slog to adoption.
For BEV’s the body is buried in the cost of the batteries, but that too will pass. Driving electrically is nothing short of a luxury. Regular cars that are closest to the smoothness and quiet of my car are up in the $200K+ Bentley class. Pretty hard not to like it since I get all of the acceleration and other goodies along with it.
V2G is, at the moment, a theory. The technology has been developed by multiple researchers. No problem there. Its just that no one or manufacturer in their right mind would allow their car to participate. Regardless of the depth of discharge, it ages the batteries artificially. Maybe we’ll develop some chemistries that don’t age, but we haven’t yet.
Correspondingly, the jury is still out on fast charge (level 3) as well. Extremely high C multiples also artificially age the battery. We have a ways to go here.
Shucks, I know the solution but the Utilities don’t want me to tell everyone. In the “Good Old Days” when there was no J1772 level 2 charging stations or points, (Over 2 years ago.) we recharged our conversion built EVs from the “Dryer Outlet” but there is a simpler installation setup for “Level two”that results in NO impact on the demand at the residence. It really is simple, Nearly every modern home has an Electric Hot Water Heater. Connect the “Charge point” wiring to the same circuit breaker with a relay to disconnect the water heater while the car is charging. Why the Water Heater, because it has a storage capacity of about one days usage so the charging EV has NO impact on the household routine. Presto, no impact on “Peak or Off-Peak”
Thanks for looking at the marginal effect on the grid of EVs- it’s a subject that gets too little attention (most likely because it’s so hard to get our minds around.) To add to the confusion, we need to look at both the short term effect of charging a vehicle (which power plant will be dispatched to provide the extra electricity) as well as the long term effect (given the extra demand from a large number of EVs, how with the utility supply the extra power? (this could be anything, not just renewables or fossil generation, but also possibly through demand side management (DMS) – better efficiency elsewhere freeing up power to charge cars.)
Personally, my preference is to charge my car with DSM. 😉
You’re right; it’s not as simple as most people believe. Here’s a follow-up I just wrote: http://2greenenergy.com/electric-vehicles-and-coal/32110/.
We also have the phenomenon of seeing what we want to believe. Some people hate the oil companies so much that they’re really not too anxious to take a hard look at the science. Trust me, I understand that feeling.
Again, I support EVs long-term, and if we’re going to get there, we need to start now.