Hardly a day goes by without an announcement that some company is either developing a new model of an electric powered car or has made some sort of progress on the ones under development. These announcements are coming from major automobile manufacturers all over the world and from numerous startups working in small garages. It is clear from all the activity and rapidly increasing oil prices that the day of the electric car is almost upon us. For the immediate future there is no practical alternative for personal mobility with the speed, flexibility and comfort that we have become accustomed to except the electric car.

Before we look at the various forms these electric cars might take we should answer the key question of whether there will be enough electricity to replace gasoline and diesel we currently consume in cars and trucks. In the long run the answer, of course, is “yes” – provided we can hold industrial civilizations together long enough in a era of oil depletion to produce and install the equipment necessary to supply electricity from renewable sources – solar, wind, the seas, and biomass.

A recent article in Scientific American makes the case that a massive solar power facility covering much of the southwestern U.S. could, when combined with innovative ways for storing power and a new nationwide electrical grid, provide a third of our current electric requirements within 40 years. It seems likely that even with existing technology; a decades-long crash program could cover whatever is needed As long as the sun is shining, the energy is there; all we need is the time and admittedly massive resources to convert it into usable forms.

If we can’t build the infrastructure to generate renewable forms of energy quickly enough, then the only hope is massive conservation of electricity (think no air conditioning) until such times as we can.

Our electric vehicles will come in a wider variety of shapes and sizes than have our cars. Without the luxury of powerful internal combustion engines and cheap liquid fuels, the designers of electric cars are going to design their vehicles for the utmost energy efficiency if they are going provide similar function and performance to the cars and light trucks we have today.

Some will look considerably different than we are used to. There are already a half dozen three-wheeled electric cars under development. These will have the capability of taking one or two passengers and a modest amount of stuff for hundreds of miles on a gallon of electricity-supplemented gasoline.

When electric vehicles start coming on the market in the next three to four years, they will come in several different flavors. First we will have the all electric car or light truck that will not have a gas tank and will get its power from being plugged into the grid. While battery driven cars are already available in a form known as a neighborhood electric vehicle, their performance is such, and gasoline still is so cheap and available, that they never caught on.

The coming versions of all electric cars will easily provide all the speed we can safely use and should have ranges on the order of 100 miles or better until they need to be plugged in again..

The key to the electric cars of course is the battery or other device to store the electricity. For the immediate future, the on-board power storage device of choice seems to be the lithium-ion battery. These have already been developed in numerous forms and chemistries. Manufacturers are busy trying to sort out which of these is the best fit for the size and type of electric car they are trying to design.

If the electric battery works as hoped, there are still a number of issues, such as how quickly they can be produced in large quantities, how much they will cost in large quantities, and the main question of whether there will be enough lithium to replace the 230 million cars in the U.S., the 900 million cars in the world, and the billions more that the six billion people in the world hope to own some day. This is indeed the key question of the age of the electric car.

There are other candidates for advanced electricity storage in the wings ranging from carbon foam to ultra capacitors that may prove to be more affordable and available than lithium-ion batteries. We should have better insights into this issue in the next five to ten years.

The next flavor of electric car is the plug-in hybrid, which is simply a current hybrid with a bigger battery allowing some amount of all-electric range. The extra-large hybrid battery is recharged off the grid and when depleted the vehicle reverts to normal hybrid mode. While short trips at moderate speeds from 5 to 30 or so miles without using any gasoline is possible, the power from the battery allows for much better mileage at freeway speeds for moderate length trips.

The newest and most interesting flavor of the electric car is what has become known as the extended range vehicle. This is simply an electric powered car with an on-board gasoline powered generator to recharge the batteries. The most publicized of these is under development by Chevrolet which is aiming for a 40 mile range on the electric batteries and hundreds of miles with the gasoline generator doing the recharging. This combination of electric powered wheels and an gasoline powered generator is inherently more efficient than using gasoline to drive the wheels.

As these vehicles are capable of performance similar to today’s cars using only a fraction of the liquid fuel, they are likely to come into widespread use during the time of oil depletion. Next week I would like to discuss the feasibility of electric vehicles connected to the grid.