From: John De Armond Newsgroups: rec.outdoors.rv-travel Subject: Re: Power, was Re: Propane prices Date: Mon, 08 Jan 2001 23:29:06 -0500 "George E. Cawthon" wrote: > Sorry Will, but you obviously don't know anything George, if you stop right there, you can generalize it and still hit the nail on the head. > about the PN, about > how paperplants operate here or about the electric power generation > here. Ralph is dead on. > > I don't know how you define cogeneration, but I think we define it in a > quite different manner here and the requirement of major power producers > to buy cogeneration is usually a drag and not a benefit to the consumer. He obviously doesn't have a clue as to the definition of co-generation. "Co-generation" to utility people means a facility generating part or all of its power. Typically we think of Cogen as involving using otherwise waste material or heat but not necessary. Utilities heavily encourage industrial Cogen. There are a variety of terms to refer to what you're talking about, George, the forcing of utilities to buy "toy power" from alternative generators. When I worked for TVA, we called 'em "Alternative Generators". Another commonly used term is "small source generator". Last professional job I did before retiring to the pig palace was to join a friend in a project to automate the power plant at the Westvaco kraft mill in Charleston, SC. I still occasionally consult to the Bowaters newsprint mill just up the road in Charleston, TN. The mills are quite similar in their energy needs and management. (All of this is of about '92 of course.) At Westvaco, there are 6 boilers and 5 turbines with a rotating capacity of about 150 mw. The mill uses around 150 mw when all lines are running. The mill generates enough waste to make about 50 mw. They have a negotiated price deal with the utility to receive and pay for 50 mw 24/7. They pay whether they use it or not. The deal calls for large surcharges for anything OVER 50 mw. In other words, the utility gives them a favorable price in return for becoming a curtailable base load. The objective of our project was to run the boilers on whatever combination of fuels necessary to keep the utility load at exactly 50 mw. A whole bunch of Allen Bradley/Hewlett Packard hardware and a BUNCH of HP-UL software later and that's exactly what we did. The boilers are each optimized to burn a particular fuel, be it bark and chips, saw dust, black liquor, gas, oil or coal and are capable of burning at least two other fuels each. Our control system fired boilers and brought generators up and down as needed, depending on plant load, available waste stream, spot fuel prices and a couple dozen other parameters specified by the plant. And if the utility needed to shed the mill during an energy crisis, the control system would either increase firing or send shutdown signals to various parts of the mill to enable the mill to run completely self-contained. I can guarantee that if SC was deregulated and spot power rates were approaching $1k/kwh as it is in Ca during peak loading, Westvaco would shut down the mill and send 150 mw out on the grid. Hell, they could burn Chanel No. 5 and make a profit at Ca spot market rates. The mill had an impromptu dry run during the last BIG hurricane that hit Charleston. The storm took out all the power in the area. The mill had gone to hurricane safe shutdown but the power plant was running. Unbeknownst to the mill powerhouse operators, the utility's reverse current relaying didn't work and the mill was supplying power to all of the city of North Charleston. That apparently went on for the better part of the night before someone figured out what was going on. Seemed to work quite well. A much more recent project in which I oversaw the startup testing and certification involved cogeneration but no waste heat or fuel at all. It involved installing a 0.5 mw diesel generator at a job shop fabricator to run a huge stamp mill. The stamp mill would draw almost that much power for a couple of seconds on each cycle. The idling power was under 5% of that but the power factor was very low because the motor was under-loaded. Not only would the utility have nailed them a HUGE demand surcharge, it would also nick them a second surcharge for power factor. It turned out that a generator to supply this load was cheaper than the surcharges and/or alternative power storage schemes and power factor correction. Caterpillar makes a genset just for these applications. Large flywheel mass, very low off-load BSFC and multiple fuel capability. The particular generator chosen burns either diesel or natural gas. IOW, it burns prime fuels but is cogen nonetheless. John |