In November 2015 National Geographic: A blueprint for a carbon-free America. Well, not quite. Read on.
The comments reproduced below are explicitly referring to the print edition of National Geographic.
Some comments about the big error
Richard Hahn 6 days ago
There is a serious error in the amount of land area required for a wind turbine. For example in the case of Texas on page 73 it is stated that only 6% of the states land would be required to produce half of the states electrical demand approximately 336,027 MW.
Wind turbines have a typical capacity utilization of 25% therefore 1,344,108 MW of capacity has to be installed. The American Wind Energy Association's rule of thumb is 60 acres per MW. Therefore about 81 million acres or 126,000 square miles would be required. Since Texas has a total area of 261,797 square miles the required wind turbines would take up approximately 48% of the total land area....or EIGHT TIMES what is indicated on page 73.
Most wind turbines are about 2.6 MW some bigger some smaller, but on average Texas would require 517,000 wind turbines. Assuming each turbine requires about 32 man hours per year this would require a work force of about 8,300 workers just for maintenance. And finally no where has any country been able to penetrate the electrical grid with more than 20% of the highly variable wind power.....Texas has trouble with only 10%.
The National Geographic does a disservice to our country publishing stuff like this. Wind energy will be an economic disaster for this country and it will do little to decrease carbon emissions...it is a waste of both time and money. Climate change puts the World at risk and we can't afford to make any big mistakes like this.
Richard Hahn 2 days ago
There is an error concerning the power needed by Texas in 2050. On page 73 it says the power required would be 672,054 (MW). I think this is actually 672,054 Giga Watt-Hours of "energy" not Mega Watts of "power" required.
This equates to an average generation of 76,718 MW which is a more reasonable number. If 50% of this power is to be supplied with on shore wind then 153,437 MW of wind turbine power would have to be installed. This would occupy an area of 14,385 square miles or approximately 5.5 percent of the state which agrees with the 6% stated on page 73 and if 65,000 turbines are used then each turbine would have to be about 2.4 MW which is also more realistic.
Therefore - for the record - except for the total energy required being expressed as Mega Watts instead of Giga Watt-Hours everything else appears to be correct.
However what's not indicated is how this huge conglomerate of highly variable power generators would be controlled. In addition there is no mention of the huge investment required to transmit this erratic generation. The current distribution system is totally inadequate. It will probably have to be increased in size by a factor of 3 or 4 times. There will of course be the usual right of way and environmental concerns that could take decades to get resolved if at all.
This huge, expensive global scale experiment has never been done before, I doubt if it has even been computer simulated.
Brian Fiedler 22 minutes ago
Top-left of page 70 in the print edition: "Stanford Professor Mark Jacobson has outlined a plan detailing how energy in the U.S. could be carbon free in 2050"
If the label is indeed wrong, and should be GWh per year, then the article is only about ELECTRICAL energy generation. The total power consumption by Americans (electrical, transportation, heating...) is about 10,000W. So 1 MW serves 100 Americans. Continuing with Texas as an example, 672054 MW would serve twice the current population of Texas with 10,000 W. The area of Texas is 695700 square km. 1 MW of average wind power PRODUCTION per square km of wind farm is a realistic expectation. So unless National Geographic wants to issue a retraction about "carbon-free energy", it needs to allow for half the area of Texas for wind farms to supply Texas with half of the budgeted 672054 MW.
It saddens me that the popular press consistently bungles energy reporting.
(Also, by the way, it takes power to make steel and concrete to make wind farms. This power won't be carbon-free for the first construction.)
The erroneous pages
A month later http://ngm.com/more still offers no correction:
Wind turbines do have wakes. http://www.nrel.gov/news/features/2012/1995. The turbines need to be spaced apart to increase the power production.
I will need to reference a skeptical page, but that is where you find greater numeracy http://energyskeptic.com/2015/wind/:
- Tom Gray of the American Wind Energy Association has written, “My rule of thumb is 60 acres per megawatt for wind farms on land.”
- Remember that capacity is different from actual output. Typical average output is only 25% of capacity, so the area required for a megawatt of actual output is four times the area listed here for a megawatt of capacity
Here is a presentation of my own research, which shows the difficulty of producing more than 1 W m-2, regardless of the installed capacity.