Thermodynamics was not my favorite engineering course back in college, but even I understood your well presented argument. Wish you could see similar explanation on media so people could see how ridiculous electric cars are. I do think there is some use for hybrids. They seem to make more sense, taking advantage of stored momentum and not needing external charging. But I am not convinced they are worth the extra up front cost compared to a gasoline compact.
Although the published information on the initial energy loss converting coal, natural, diesel, or other fuels to electricity is consistent and can be figured into these types of calculations. The published information varies greatly on what the average power loss actually is in transmission through transformers into the power grid and back at the local level in the series of step down transformers up to the one in front of your home and then even the service drop and wiring within your home.
This is because these numbers can and do vary greatly on a case by case basis depending on the region, the ambient air temperature, and the actual load on the transmission conductors. These numbers cannot really be calculated precisely except on a case by case basis where all of the variables are known. Maybe one day in our “digital” world with networked metering this will be economical and worthwhile to figure.
As outside ambient air temperatures increase and the load on the power grid gets closer to it's "maximum" capacity the resistance and temperature of the lines increases and their efficiency and heat loss can increase greatly. The same goes for the transformers and even the service drop to your home and your house wiring. So we have this impacting the actual efficiency of using and charging electric vehicles in the summer.
But I failed to mention in my previous posts the most important limitation variable on Lithium Ion battery capacity for a good percentage of the United States during several months of the year. Lithium Ion batteries can be charged only when their temperature is between 32F and 113F. If you attempt to charge them if the ambient temperature of the cells are below 32F or above 113F they can and likely will be damaged and can become dangerous. They can also be damaged if the ambient temperatures of the packs are below freezing and you try to put a load on them although this is not as likely because they basically stop working at low temperatures. So during cold weather electric cars can just plain become unusable altogether.
If the car is kept inside a heated garage and you are able to drive it to another heated garage things will probably work out alright, but if you make a stop along the way things could become iffy within a short period of time depending on the outside air temperatures. So we can conclude also that it is not a good idea to use your electric car to drive up into the mountains to go skiing.
Some people may have noted that when it is warm outside that the temperatures inside your car become far warmer. This can be a problem for electric cars. If the batteries are warmer than 113F and you put a load on them bad things can and do happen. The extremes we all know of are exploding cell phones and other battery powered electric powered devices. But irreversible damage can also be done to your electric cars extremely expensive battery pack.
I have been restoring a rare 1942 Cadillac. It has a cabin heating system, but this was an option even for Cadillac before WWII. These days most of us expect to have our cabin temperatures to be within a certain and fairly precise temperature range for our comfort. This requires additional energy to provide, but in gasoline powered cars waste heat from the engine is used in the winter and the energy used by the air conditioner in the summer typically barely makes a dent in your mpg. It is a different story altogether for electric vehicles where this additional power drain can be a large percentage of the power being used for propulsion and can dramatically reduce your range, especially in the winter.
In conclusion, I doubt whether most people interested in purchasing an electric car will be swayed by my numbers or my observations. For those people I have saved this nugget for last. If you buy an electric car or even an expensive hybrid with an expensive battery... pay for whatever insurance policy is made available to you at the time of purchase for that battery. These types of policies are usually a waste of money, but not in this instance. This is not a mature technology, so bite the bullet on this one or you could be very sorry.