I wrote:
> This is 110 MW on 1,600 acres. That is excellent power density. Better > than uranium fission or coal, when you take into account the land needed > for the mines and railroads to transport the fuel. > I do not know how much coal a 1,600 acre strip mine would produce, but I am sure it would produce 110 MW continuously for, let us say, 100 years. Whereas the land devoted to the CSP will continue to produce 110 MW for the next several billion years. To say this power density or energy density is low is ridiculous. Here is a source that claims that it generally takes about 314.1 acres to produce a million tons of coal: http://www.sourcewatch.org/index.php?title=The_footprint_of_coal#National_estimate_for_U.S._.28excluding_Wyoming.29:_314.1_acres_per_million_tons I assume those are U.S. tons. Various sources claim that coal has 15 to 20 million BTU per ton, depending on the type of coal. Roughly 35% converts to electricity with a modern plant, so that's around 7 million BTU. That's 7,385 MJ per ton, or 2.05 megawatt hours. That is electricity, after you burn the coal. Okay, so we have 1,600 acres. If that was an average strip mine it would produce 5.09 million tons before it is played out. That is 10.4 million MWH of electricity. The 110 MW CSP solar plant produces that much in . . . 94,932 hours of operation. Daylight peak hours, that is. That is 3,956 days. Or 11 years. Of course the solar plant does not produce power 24 hours a day, but we do not need power 24 hours a day either. A coal fired plant is not needed 24 hours a day at full power. Or if it is used for baseline generation, that means a gas-fired plant somewhere is shut down at night. You still have to pay for the gas turbine equipment, even though you do not use it at night. The bank charges interest 24 hours a day. Assuming the CSP produces 1/3 of peak power on average, that means the 1,600 acre installation will produce as much power as a 1,600 acre strip mine every 33 years. After 330 years it has produces 10 times better energy density than the strip mine, and far better power density. You can use it indefinitely, millions or billions of years into the future, and it will still be producing 110 MW. I have not even added in the space taken by the railroads needed to transport the coal. I have not added in the living space destroyed by rising ocean waters from global warming. Or the extra space devoted to high tension power lines and the cost of wasted electricity caused by the fact that you have to put coal fired plants far from cities, so you do not kill off rich people, whereas you can put a CSP right next to a population center in a place like Nevada. - Jed
