GreenCar Depot Blog

We are going to see a number of electric vehicles entering the marketplace in the next few years, as well as plug-in hybrid models. Many are offering extended range and highway speeds, so they will become attractive to a market that previously wouldn’t seriously consider these vehicles. One often asked questions goes something like this: “while the vehicle itself might not emit pollution from the tail pipe, the electric power plant certainly did produce noxious emissions, and how does this compare to a standard vehicle?”.

It turns out that this is not an easy question to answer. Power companies typically generate power from a variety of sources, including everything from dirty coal to clean solar power, as well as wind, natural gas, hydroelectric, nuclear, and others. So depending on your given company’s mix of power generation, the emissions will be different. Some electric companies offer the consumer a choice. Here in Southern Oregon we can choose a “Blue Sky” plan, which means that all of your power will come from “clean” sources. Obviously this doesn’t mean that the actual power going to your house is from clean sources, but it does mean that your power company will increase the proportion of the alternative energy sources that it uses accordingly.

One interesting concept in power generation is the “smart grid” or “smart charging”. This idea is based on the concept of selectively charging electric cars while the demand on the gird is low, such as in the middle of the night. It turns out that power companies don’t generate power on demand. They currently have no way to store extra power and they cannot quickly and easily increase power, so they operate on predicted demand levels, generating an excess to make sure there is not a partial power outage. The down side is that any power that is not used is wasted. As you can imagine, they do not have a giant battery bank sitting around to store excess power. As a result, during low demand times there is more power wasted. If we can charge electric cars during these down times, we can have very little overall increase in emissions, since this would be consuming power that is generated and otherwise not used.

Overall, I think electric vehicles charged with solar and wind power are probably the best thing going. For most consumers, though, this might not be a realistic option. Choosing a clean power plan from your utility (if offered) coupled with charging during low demand hours is a good strategy to make sure your EV or plug-in hybrid produces low emissions. Oh, remember I mentioned that utilities don’t have giant battery banks…well there is even a concept to use all of these plugged-in electric vehicles as a giant battery bank to store power for the grid in the event of an emergency.