Book Review – Plug-in Hybrids: The Cars That Will Recharge America

I read an interesting book on the weekend by Sherry Boschert, that certainly has some interesting ideas.
I have a particular interest in the possibility of plug-in hybrids.  My 6 year old Honda Insight has 246,000 km on it, and while it is still working well, with original batteries, its days may be numbered.  And I have a significant interest in a wind farm.  The idea of supplying some of my own fuel for driving is appealing.  It may not be quite as potent as my brother who drives on biodiesel all the time, but you have to start somewhere.

The book paints an interesting picture, and describes the energy and enthusiasm of CalCars, a grassroots group who has actually taken hybrid vehicles, added batteries, and a cord, and modified the car’s software, to make the first plug in hybrids.  It always fascinates me how the actions of just a few people has the potential to make such a big difference.

The idea behind plug-in hybrids is that you plug them in when you are not driving, and charge batteries.  The car then runs for the first few miles of your next trip on battery power alone.  Needless to say, this can cut your gasoline consumption considerably, depending on your battery range.  Of course you still have your underlying gas fired vehicle, so, you can drive even once the batteries are depleted.

The concept offers significant possibilities to reduce petroleum consumption.  Because re-charging of batteries is done at night, the electrical grid would generally need to add no new capacity, but power plants would need to run more at night, so electricity emissions would increase if the source of electricity was fossil fuel.   If you could could co-ordinate the recharging to match times of surplus renewable energy, for example in a system with significant wind installed, the opportunity to reduce emissions can be further enhanced.
The efficiencies of electric cars are outlined in detail, with many studies cited.  Because batteries and electric engines are so much more efficient than internal combustion engines, even in an electric grid that is all coal based, overall emissions would go down.  A study by Sacramento Municipal Utility District showed that an electric car is twice as efficient as a gasoline car, even factoring in the inefficiencies of producing electricity from fossil fuels.  Twice as much of the energy in the fossil fuel to make electricity hits the wheels, compared to the energy to hit the wheels from burning gasoline.  The result is that even if electricity is slightly more expensive per unit of energy than gasoline, the cost of using electricity for the first few miles of your trip is about half the cost of using gasoline.

The key technical challenge of electric cars in the past has been battery technology.  You want to get a long range, with minimal weight and space.  Unlike conventional hybrid car batteries, which discharge and recharge frequently, and rarely do a deep discharge, plug-in hybrid batteries will need to be able to handle deep discharge.  Recharging time may matter to some.  The first back yard conversions used lead acid batteries.  It worked, but range was limited, and the weight, and therefore the efficiency of the vehicle was reduced.  Later conversions used Nickel Metal Hydride, similar to early laptop batteries.  These increased the range, and reduced weight.  Further gains may be possible with Lithium Ion batteries, which is the battery GM has chosen for it’s announced plug in hybrid (delivery 2010).

The backyarders proved it was possible.  And the book makes a compelling case that it will be economic, with lower fuel costs (electricity vs gasoline) offsetting the higher price of a vehicle, once volume is reached on the vehicle production.  And the volume that was required to make economic sense was quite low – about 100,000 vehicles/year, or less than 1/2 of 1% of the North American market.  Should be easy to get to.  And further, it should be something car makers should be interested in.  After all, consumers will pay more for a car that costs them less to drive.  The economic value of fuel will be transferred to the car company and utility, from the oil company.

A key question that kept haunting me was: how far can you drive on a charge?  And of course the answer is:  it depends.  It depends on the batteries selected, and how many you install.  It depends on the weight, aerodynamics, and efficiency of your car.  But it seem likely that a plug in hybrid should be able to go at least 10 miles on a charge, before requiring gasoline, and up to as much as 30-40 miles (the EV1 went 140 miles on a charge).  It will depend on the tradeoffs the manufacturers make in weight, range, battery type, cost etc.  Perhaps consumers will end of with a choice, that best suits their driving habits.  Even 10 miles is significant.  A US Personal Transportation study estimates that 50% of American drivers drive 25 miles or less per day, and 80% drive less than 50 miles.

Many people seem to want a silver bullet to solve the world’s environmental problems.  But a silver bullet doesn’t exist.  But silver buckshot exists.  And that is where plug-in hybrids may fit.

The book takes a very American approach, with a greater emphasis on fuel security than environmental improvement.  The book points out how plug-in hybrids are a rare example of something that can unite the security conscious Right with the Environmental conscience of the left.   It is a good read if you like cars, if you like stories of backyarders making a difference, or if you want to better understand the environmental implications of plug-in hybrids.  I am convinced they are on the way.

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