Of course the miles per kilowatt-hour is probably reported for new batteries that have not been discharged and recharged several times. It might be noticed for example that a charge on batteries for notebook computers does not last as long as reported and as the batteries age the charges last even less long.
It becomes difficult then to say with certainty whether the electric vehicle makes sense yet, especially considering the high cost of eventually replacing the numerous, large batteries altogether. It might be true though that the transmission has been improved enough to actually take meaningful advantage of getting charging action from a braking action. That could explain the claims. Of course air conditioning and heating from electricity use large amounts of power that cannot be so recovered.
If electric cars are charged at stations that get power from renewable energy then of course those vehicles have a much smaller carbon footprint. Most areas do not have such stations though.
The situation deserves continued study, especially long term studies that consider battery replacement. Your anecdotal data is welcome. Email your stories to op.ed@thetownvoice.net. All data is anecdotal in the beginning. Your comments may appear in the following section if you wish.
In addition to possibly using more fossil fuels than vehicles powered directly by fossil fuels, even if they use less the electric vehicles still use large quantities of fossil fuels such as will not be available obviously when fossil fuels eventually run out. Driving 20 miles to work each day won't be practical, even with an electric vehicle. Renewable energy sources are not responsible for the freedom currently available with electric vehicles such as it might be. Electric vehicles are still burning fossil fuels, just not on board the vehicle.
Electric vehicles are still a work in progress. Their advantages might improve over time. Renewable energy is still a work in progress. At the current state of the technology wind farms and solar panels would have to choke all the landscape in order to provide energy for current lifestyle consumption levels, and even then fall short.\
Let's go, people, two odometer readings and a receipt from the charging station for the amount of kilowatt-hours needed to cover that distance, pictures or it didn't happen.
On further review it does not seem there will be any evidence electric vehicles use less fossil fuels when the electricity they use comes from burning fossil fuels. Rather they use more. The explanation is a bit long, but here it is.
It is apparently a popular fantasy these days that electric vehicles can get extremely better mileage because they can recover some electric power when "braking" by converting momentum back to electrical energy. That is, by using the motor as a generator or a using a separate generator. If a vehicle were like a hockey puck on virtually frictionless ice that might be possible. If the friction between the ice and the puck could be zero, the mileage of the puck would go to infinity providing the puck travels in a straight line and there is enough ice. Acceleration requires energy and deceleration involves a transfer of energy, but constant straight line motion, as Newton confirmed, does not require energy at all.
The bad news is that neither the puck nor the vehicle encounter zero friction. Well oiled metal parts reduce friction significantly, but they cannot eliminate friction. Streamlining can reduce the resistance of the air, but again cannot eliminate that friction. Fidget spinners can spin for very long times because the "load" they bear is very small. The load of a vehicle means there will be far more friction.
Now consider a vehicle traveling in a straight line at a constant speed on the highway for example. If the friction were zero the vehicle should require no fuel at all to maintain speed. Highway mileage is typically much better because of straight line constant motion, but it is not infinity. That is because the friction is so significant. The momentum of a vehicle is not increasing, yet energy must be expended to maintain constant velocity against the friction. Since the momentum is not increasing the energy used that way cannot be recovered when "braking." The only return of energy possible is from the increase in momentum during the brief acceleration to reach highway speed. Even that cannot be recovered entirely because of the losses according to the 2nd law of thermodynamics.
At lower speeds there is less wind resistance, but the friction of metal parts is the same or worse because of the difference between static and kinetic friction.
These facts make the notion that electric vehicles can use less fossil fuels when their electricity comes from fossil fuels highly unlikely. They probably use more. The claims on the internet otherwise are probably false, and that is the problem with the internet. Time will tell Of course when their electricity comes from renewable energy like hydropower, electric vehicles do have a much smaller carbon footprint. Few people live where hydroelectric power is available though and other renewable energy sources do not provide the vast quantities of power fossil fuels can. That is why I asked the Virginia legislature to pass a law requiring charging stations to post whether and how much the source of their electricity is from fossil fuels.