This morning’s author examines the role of electric cars in our human future.
Are Electric Cars the Future?
Donald B. Halcom, Ph.D.
The automobile industry is undergoing a revolution. This is about the new Tesla Model S and Nissan Leaf all electric automobiles. I thought it would be interesting to estimate some of their impacts upon the future. These calculations are exaggerated but make some strong points.
Example Current Data
Current registered automobiles in California = 22,083,049 (I picked this state as the example.)
Current Total Electric Power production capacity in California = 69,709 megawatts
Tesla Model S Super Charger = 120 kilowatts (fully charge a Tesla Model S in about two hours). The current lithium-ion batteries overheat if charged too fast. Longer charging times mean that fewer Tesla’s can be serviced per day.
Calculation for the Tesla Model S
A back calculation is as follows:
California Total Electric Power = 69.7 gigawatts = 69.7 E 9 watts
Tesla Super Charger 120 kilowatts = 12 E 4 watts
Maximum Total Charging Units Equivalent = 69.7 E9 / 12 E 4 = 5.808 E 5 Tesla Super Chargers
This equals 5.808 E 4 Charging Stations with ten super chargers per station or 58,000 charging stations in the state of California. How many Tesla Model S electric cars can the state’s electric system support? Assume that 8.33 % (2 hours out of 24 hours per day) of all of the Tesla’s are being fully charged every day. What is the absolute maximum number of Tesla’s that California could support? This number is:
5.808 E 5 / 0.0833 = 6,972,389 Tesla’s or 32% of the total registered automobiles currently in California.
This is the equivalent of one full charge per day for 6,972,389 Tesla’s. These Tesla’s could only travel about 250 miles per day. The power rating for the Tesla is about 350 hp. There would be no electricity to power the rest of California. This electric car will not solve our problems. This car was given a rating of 99 by Consumer Reports. Why? The last thing that this planet needs is another set of 350 hp cars. The design of this car was aimed at wealthy people with no appreciation for the reality of charging them. Citizens of the USA still tend to be short sighted. In the not too distant future, we will all realize the planet will flat run out of fossil fuels. At that point, about 100 hp electric cars will be practical but not 350 hp monsters. Power mad drivers should go forth and have chariot races.
Some will consider these calculations to be absolutely absurd. Why would the population of the entire state of California ever drive only the Tesla Model S? They would not.
The world tends to run on peer pressure and in it, bigger and faster equals better. The pressure is to drive Mercedes, BMW, Lincoln, Lexus, Cadillac, Corvette and the list goes on. These are not 100 hp cars. They are all like the 350 hp Tesla. Even the smaller current cars are more than 100 hp (e.g. Civic, VW, etc.). The new Nissan Leaf all electric car is 110 hp. Notice that the examples used in these calculations are based upon one current constant amount of electric power generation for California. There must be a constant reference point in order to make consistent calculations.
Calculation for the Nissan Leaf Electric Car
The data for the Nissan Leaf electric car indicates that using a 240 volt home charging unit, the power draw is 5.2 kilowatts and the full charge time is 8 hours. This full charge time is 33.33 percent of a day for each car. For the Nissan Leaf:
Total California Charging Units Equivalent = 69.7 E9 / 5.2 E3 = 13,403,846 Nissan Leaf chargers
13.4 E6 / 0.3333 = 40,200,000. This is the absolute maximum number of Nissan Leaf electric cars currently possible in California using one charge per day.
This is 182% of the current cars in California. Each Nissan Leaf could travel about 84 miles per day. This distance is significantly less than the Tesla but there could be far more Nissan Leaf electric cars than Tesla electric cars. . You can drive about six 100 hp electric cars for the energy consumption of one 350 hp electric car.
My vote is for something like the Nissan Leaf and not the Tesla. In the future, all long distance travel would have to be by mass transit. Electric cars would be limited to local travel. Electric trains could supply the mass transportation and some freight transportation.
Our current Interstate Highways would be limited mostly to trucks burning BioDiesel fuel. We must all change our current thought processes in order to survive a drastically different future. Global warming is not our only dilemma for the future. Replacing the energy from the depleted fossil fuels represents, in my opinion, an even greater threat. These things cannot be done overnight. It will take decades. We must choose wisely and begin now.
Don Halcom has a Ph.D in Chemical Engineering. He is in his mid-70s, and retired. He is available to respond to any follow up questions you may have. You can reach him here: drdon (dot) halcom (at) verizon (dot) net