Thursday, July 15, 2010

Flawed arguments against Electric Vehicles

I keep hearing the argument about how plug-in electric cars don't save anything because you still have to generate electricity at the power plant. This argument is flawed.

Before getting into that I need to point out that some might consider my view biased. In a past life I designed Coal Mining equipment, and I'm still involved with Mine Safety and Health Administration (MSHA) and the Coal Ming section of CDC/NIOSH. See our A Technology Review of Smart Sensors with Wireless Networks for Applications in Hazardous Work Environments booklet for example. A bit outdated now, written before most people had heard of wireless sensors or energy harvesting. Now with that out of the way, lets move on...

The major design goal of any moving vehicle is to keep its weight down. Right now each and every car out there has to carry the weight of its own pollution control system around. That takes energy in and of itself.

Putting the pollution control system at the power plant has no issues of weight so they can be far more effective. Since the electric car no longer has to consume energy to move around its own pollution system there is an over all savings of resources.

What is more importantly overlooked is the resources consumed in making the pollution control system for every existing gas powered vehicle.

Resources such as Palladium and other metals are used to make Catalytic Converters, which takes significant energy in the manufacturing process. There are may other resources also consumed to manufacture these pollution control systems.

Something else most always over looked in the discussion of hybrid vehicles just moving the pollution form the tail pipe to the smoke stack, is Regenerative Braking.

In both conventional and hybrid/electric vehicles energy is used to get the vehicle moving, in other words the fuel is converted in to kinetic energy. However there is a significant difference in how energy is used to get the respective vehicle types stopped.

A conventional vehicle uses friction heating to dissipate the energy that was used to get the vehicle moving in the first place. Applying the brakes causes the brake pads to engage to slow the vehicle to a stop by dissipating the kinetic energy as heat through friction. That heat goes into the environment, and is totally wasted.

On the other hand, a properly designed hybrid or electric vehicle will use Regenerative Braking to return the kinetic energy back into stored energy in the systems batteries or capacitors. There will be some small amount of energy lost to the environment, due to the system not being 100% efficient.

The bottom line is that the existing vehicles waste nearly 100% of their stopping energy, while a electric vehicle will recover significant amounts of their stopping energy, which will approach 100% recovery as technology advances.

One final thought. Did auto and oil companies gang up to kill the electric car? Check out 2006 documentary film "Who killed the electric car?".