Quote:
Originally Posted by Rich H
Unfortunately, Tesla's figures do not reflect reality.
1. Natural gas power plants, in the real world, consume about 10,000 BTU +/- to produce one kilowatt-hour, at the output terminals of the generator. Crunch the numbers, even using Tesla's mileage claim of 110 watt-hours per kilometer, and you end up with a gasoline energy mpg equivalent in the 50 +/- range.
2. And suggesting that electric cars will be recharged using today's power plant mix, or entirely solar/wind, is a pipe dream. The fact is that adding significant numbers of electric cars to the grid, regardless of the time of day, will force the addition of new power plants, and those will be coal and natural gas fired, unless a broad consumer willingness suddenly emerges to pay the significantly higher cost to produce electricity from non fossil sources. And even in that case, natural gas additions will still be required to maintain grid reliability.
Despite the hype, electric cars are just not perpetual motion machines.
One Tesla suggestion is, however, true. If electric car owners charged their cars entirely from off-the-grid solar panels installed at their homes, the result would likely be a net energy/emissions benefit to society (depending upon the resource cost to make and dispose of the car batteries and solar panels). The problem, of course, is that virtually no car buyer will go to the expense, difficulty, and inconvenience of building a self-contained charging station that only works when the sun is shining.
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Thanks for pointing this out, rich. The tesla reports are a great example of additive hopeful estimation: you want to make something look really good so what you do is look at all the figure ranges and then take the best possble numbers in each area and put them all together with the most hopeful sets of circumstances to produce a very nice looking end result.
(e.g. If everyone builds their own solar electric charging stations and the sun shines 365 days a year and new cheap natural gas is found then you will actually make money every mile you drive your tesla
)
The point is that even though some of the estimates are theoretically possible, they are almost all practically impossible even when looking at them individually.