Large base load nuclear and coal fired plants are not unresponsive. They can reduce load from 100% to 50% in a matter of minutes. The water volume is not an issue.
Utilities are about producing power as cheaply as possible. It is expensive to run these large units at reduced power for several reasons that go beyond serious efficiency losses. Large daily load swings rapidly consume thermal fatigue life of major components. In the case of nuclear, some of the main areas of concern are components that are irreplaceable. Examples are the various pipe connections to reactor vessels and steam generators. Operating coal units at reduced load causes accelerated corrosion of some components, particularly the regenerative air heater that removes waste heat from the exhaust gas and transfers the heat to the incoming combustion air. These air heaters are huge rotating cylinders filled with tons of steel heat absorbing elements. At low loads, these heaters suffer cold end corrosion that rots out the elements requiring expensive repairs. Low load operation also causes erosion of expensive control valve seats and cavitation damage. It is not cost effective to allow wind turbines to force these base load units into low load operation. Coal fired plants burn coal dust. The dust is produced by pulverizing the coal in huge ball mills then blowing it into the furnace. This process approximates the characteristics of a gaseous fuel. Jeff -----Original Message----- From: mix...@bigpond.com [mailto:mix...@bigpond.com] Sent: Saturday, March 07, 2009 7:26 PM To: vortex-l@eskimo.com Subject: Re: [Vo]:Energy News of the Weird: Denmark tilting at windmills In reply to Horace Heffner's message of Sat, 7 Mar 2009 10:49:46 -0900: Hi, [snip] >The problem most likely is perhaps the utility has too large a base >load supply, coal or nuclear, which is unresponsive to load changes. [snip] I agree, however, I don't understand why coal fired plants have to be unresponsive. It must be due to the mass of the water in the boilers. If so, then the obvious solution would seem to be to reduce the mass of water. This can be done by using lots of thin pipes to carry the water, and by increasing the flow rate through those pipes. Another option would be to gasify the coal first as has been variously proposed, thus essentially turning the plant into a gas fired plant anyway, and giving it the response typical of gas turbines. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/Project.html
