michael
Well-known member
There was recently a Wall Street Journal article on EVs,
http://www.wsj.com/articles/should-you-buy-an-electric-car-1416777176?mod=trending_now_7
There were hundreds of responses, mostly from EV haters whose reasoning ranged from "Grab of tax money..." to "my Diesel truck is efficient and works for me"
But there was one specific objection that caught my attention.
A Joesph Rizzo wrote:
Do the math. If all automobiles were electric, here is what would happen.
One gallon of gasoline has the equivalent power of 33.7 kw of electricity.
There are 368.5 millions of gallons of gasoline sold every day. This equals a requirement of 12,418,450,000 KWh of additional power to be generated every day. Divide by 1,000 to get mega watts and it is 12,418,450 megawatts of additional power to be generated every day. Divide that number by one of the largest generators built today, 1600 megawatts, and you have the need for 7,761 additional generators that must be installed....
Basically, he was saying there's no way to keep the cars charged. Nobody disputed his reasoning. I think it deserves a response.
Let's for a moment ignore the underlying error that all gasoline consumption could be replaced by electricity. Let's ignore airplanes, boats, lawnmowers, etc, and imagine that tomorrow morning the EV fairy would replace every gas burning motor vehicle with a 300-mile capable Focus Electric with a fast charging port.
In that case, it would be close enough to say that 368 million gallons a day (12 TeraWattHours per day) worth of energy would be avoided. Here he makes his first mistake. Since EVs are between two and three times more efficient than gas cars (100 MPGe typical vs 30 MPG typical, 50 MPG for the best hybrids) the energy requirement would immediately drop to perhaps 4 to 6 TWH/day. Let's be pessimistic and say 6 TWH/day.
Here Mr Rizzo makes his big faux pas. He goes from 12 TWH/day to 12 TW, forgetting that there are 24 hours in a day.
US generating capacity is approximately 1 TW, not including sources less that 1 MW. On a hot summer afternoon, this capacity may be utilized at up to 80%, a national usage of approximately 0.8 TW. As we all know, usage is less late at night and early mornings, and it is less in cooler months. However, running continuously at 80% utilization, our existing generating capacity can produce 0.8 x 24 = roughly 20 TWH in a 24 hour period. Over the entire year, the average daily consumption is about 11 TWH/day. Obviously more in the summer, less in the winter. Summer months maybe 16 TWH per day.
So we could generate 20 TWH/day (by running our existing capacity 24/7), we need about 16 TWH/day in the summer, so there are 4 TWH/day left over which is almost enough to charge every single gas burning car, truck, airplane, boat, and lawnmower in America (if converted to electric), even in the summer, provided only that they charge off peak hours.
Obviously all gas consumption won't be replaced, and the process of conversion is pretty slow. If you consider a dream scenario where half the gasoline consumption is replaced by electricity in 10 or 20 years, it will be easy to find the capacity.
The point is that even without adding any generating capacity, just by running our existing capacity more fully, we could do far more than we will actually need to in the forseeable future.
Everybody has a reason why EV's won't work, but almost everybody who tries one finds that they do.
http://www.wsj.com/articles/should-you-buy-an-electric-car-1416777176?mod=trending_now_7
There were hundreds of responses, mostly from EV haters whose reasoning ranged from "Grab of tax money..." to "my Diesel truck is efficient and works for me"
But there was one specific objection that caught my attention.
A Joesph Rizzo wrote:
Do the math. If all automobiles were electric, here is what would happen.
One gallon of gasoline has the equivalent power of 33.7 kw of electricity.
There are 368.5 millions of gallons of gasoline sold every day. This equals a requirement of 12,418,450,000 KWh of additional power to be generated every day. Divide by 1,000 to get mega watts and it is 12,418,450 megawatts of additional power to be generated every day. Divide that number by one of the largest generators built today, 1600 megawatts, and you have the need for 7,761 additional generators that must be installed....
Basically, he was saying there's no way to keep the cars charged. Nobody disputed his reasoning. I think it deserves a response.
Let's for a moment ignore the underlying error that all gasoline consumption could be replaced by electricity. Let's ignore airplanes, boats, lawnmowers, etc, and imagine that tomorrow morning the EV fairy would replace every gas burning motor vehicle with a 300-mile capable Focus Electric with a fast charging port.
In that case, it would be close enough to say that 368 million gallons a day (12 TeraWattHours per day) worth of energy would be avoided. Here he makes his first mistake. Since EVs are between two and three times more efficient than gas cars (100 MPGe typical vs 30 MPG typical, 50 MPG for the best hybrids) the energy requirement would immediately drop to perhaps 4 to 6 TWH/day. Let's be pessimistic and say 6 TWH/day.
Here Mr Rizzo makes his big faux pas. He goes from 12 TWH/day to 12 TW, forgetting that there are 24 hours in a day.
US generating capacity is approximately 1 TW, not including sources less that 1 MW. On a hot summer afternoon, this capacity may be utilized at up to 80%, a national usage of approximately 0.8 TW. As we all know, usage is less late at night and early mornings, and it is less in cooler months. However, running continuously at 80% utilization, our existing generating capacity can produce 0.8 x 24 = roughly 20 TWH in a 24 hour period. Over the entire year, the average daily consumption is about 11 TWH/day. Obviously more in the summer, less in the winter. Summer months maybe 16 TWH per day.
So we could generate 20 TWH/day (by running our existing capacity 24/7), we need about 16 TWH/day in the summer, so there are 4 TWH/day left over which is almost enough to charge every single gas burning car, truck, airplane, boat, and lawnmower in America (if converted to electric), even in the summer, provided only that they charge off peak hours.
Obviously all gas consumption won't be replaced, and the process of conversion is pretty slow. If you consider a dream scenario where half the gasoline consumption is replaced by electricity in 10 or 20 years, it will be easy to find the capacity.
The point is that even without adding any generating capacity, just by running our existing capacity more fully, we could do far more than we will actually need to in the forseeable future.
Everybody has a reason why EV's won't work, but almost everybody who tries one finds that they do.