From the title you might think this post is about the auto drive feature. This post is about what I believe drives the Tesla / Solar City merger. While in Dubai last year attending the Future Cities conference, I met another engineering colleague in a British Pub at the base of one of the local landmarks and did what most engineers do over a beer: solve the world’s problems; at least the ones that involve math and science.
We talked about the world of electric cars and I explained the world is not ready for electric cars- of course he took the bait. I explained that we had run the numbers on what had better performance; an electric car, charged from the grid, going 40 miles; or a gasoline (petrol) powered car selected to go 40 miles on a gallon of gas. Would you believe the gasoline vehicle, wins?
Please explain? Before I do, I will tell you the colleague from Dubai enjoyed the simple math and wondered how the world of environmentalists had overlooked the high tech mistake. The evening ended with two engineers feeling very sure we had solved some of the world’s problems. A few months go by. Then I get an excited email from Dubai- he confirms the calculations discussed in an article in the BBC. http://www.bbc.com/autos/story/20160316-questioning-electric-vehicles-green-cred
If you take the time to read the article, you find that a Tesla Model S owner in Singapore was expecting a rebate for buying an environmentally friendly electric vehicle. Instead, the government fined him $10,800 US for driving what the government labeled a “gross polluter”. The article is written in SI units, so I will convert a few of the numbers.
According to EIA.gov, the electrical grid connected to a coal fired plant, produces just over 2 lbs of CO2 per KWh of electricity, now consider the losses getting it from the coal fired plant to your house, then factor in the inefficiencies and losses from the charger and you begin to peel back the nightmare. Engineering can bore and lose some in the details. I will take the information published by Telsa and get: 40 miles of driving, and charging the car with 13.2 KWh, at 12 cents/kw or roughly a cost of $1.58. Now, carbon accounting 13.2 KWh at 2 lbs of carbon emissions per KWh and you created 26 lbs of carbon emissions to drive 40 miles.
Suppose I have a car that goes 40 miles on a gallon of gas. The cost of fuel is around $3.00. But according to EIA.gov figures, gasoline with 10% blend is right at 18 lbs of CO2 per gallon. For those that like percentages, the electric car produces 44% more carbon emissions. Said another way, the electric car has the same carbon efficiency as a gasoline car that goes 23 miles to the gallon. And this is where my colleague in Dubai reminded me: “You forgot to factor in the $90,000 price tag.”
This is where the title of the post comes into play: This is not Tesla’s fault. The fault lies in the legacy electrical grid that produces 2 units of greenhouse emissions for every unit of energy sold. How did the environmentalists miss this? Why did it take the country that created the Singapore math learning system to point this out for the rest of the us? Tesla / Solar City is necessary to charge cars from solar, not the grid. The sad part of this conversation few want to address is the fact that the sun shines, on average 8 hours a day. Are we going to collect and store enough solar to avoid fossil fuels and the resulting greenhouse gas emissions? How do we use technology to bridge the other 16 hours of the day and create sustainable survival? ….back to Dubai for a few more beers.