Hoping to set the electric car story straight, I wrote last week about the Chevy Volt. But some context may be necessary to make the distinctions more clear. Currently the Toyota Prius and various of the Honda cars have what is called “parallel hybrid” drivetrains. These are systems where the car can run on a combustion engine and drivetrain, or it can operate on an electric motor and drivetrain. And there is a complex balancing act required to get the best mileage out of the vehicle. Some of that balancing act is based on the programming of the 4 Power PC modules which control the vehicle and make some of the decisions about which system is operating, and some of the performance is based on the driver’s ability to control the vehicle to help achieve the best mileage possible.
So let’s put this in context. The obvious goal of electric car engineering is to achieve a pure electric vehicle which is one that runs off of a battery pack and nothing else. But the automotive community put an artificial performance metric of 400 miles per charge in order for an electric car to be equivalent to a combustion powered vehicle. Because a minivan with 26 gallons of gasoline can drive 468 miles without refueling.
But how many times do we need to go 468 miles. At 65 miles an hour that would be 7.2 hours. That’s not a typical daily commute for most people. So some of the smart marketeers in the smaller companies started saying, we can do shorter range vehicles because an average commute of 60 miles one way is only 120 miles a day, and if we can achieve that range, then the owner can charge the car overnight. So there began to be a number “out of the box” thinkers offering to manufacture the NEV – the neighborhood electric vehicle. And a new industry was born based on the golf carts and industrial vehicles that have been around for year. And yes, they can get you to the grocery store and back. The Th!nk vehicle which was purchased for sale by Ford for the US market, will be back next year with a 120 mile per day pure electric vehicle. The Tesla Roadster is a pure electric vehicle.
If you consider electric cars in comparison to combustion vehicles you have to have a different system. The California Air Resource Board considers ZEV – Zero Emission Vehicles (which is intended to mean pure battery electric) and NZEV – Near Zero Emission Vehicles (which is intended to mean hybrids) as the major categories. Their measuring stick is the amount of CO2 and NO per mile driven is being put into California’s air. Different perspective.
But no one developing these technologies could forsee the ingenious variations that were spawned by government funded development programs. There is an electric starter/alternator that was developed to sit where the clutch used to go in one demonstration program. It could start the engine in 20 milliseconds and generate electricity or act as a motor and electric power assist the drivetrain. You could stop the engine at traffic lights and as soon as you put your foot on the gas, take off again. Very clever. Great mileage too!
But all the recent “catch up” activity is a by product of the lithium battery. We knew, back in the 1990’s that the battery mass fraction was the key. Lead Acid batteries are too heavy. GM found that out with their Lead Acid EV-1. We knew that if we could get a 4 times improvement in energy density, anything was possible. And indeed, it appears that the age of the electric car is upon us.