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We all know when an international crisis rears it's ugly head the first thing the President asks is "Where are the ELTS?"
Alright, everybody. Brace for ignorance. I have questions.Many of you out there already know my level of understanding of power generation. I don't really know anything at all about "the grid," except that my lights turn on and I pay a bill to my local utility wherever I live. I wonder, as a response to this post, what happens when a big plant shuts down. I know that plants shut down for outages or due to trips all the time, but is there an appreciable increased load on other plants/units when one plant/unit shuts down?What is the long-term impact on other, nearby plants when a plant decommissions?
I wonder, as a response to this post, what happens when a big plant shuts down. I know that plants shut down for outages or due to trips all the time, but is there an appreciable increased load on other plants/units when one plant/unit shuts down?
...Long-term loss like a decommissioning: Depending upon the fuel profile of generators near major consumers, energy bid prices will go up based on what other fuel prices and capacity factors are nearby. Large baseload coal units can cost anywhere from $10-30/MWH, simple cycle gas with $6/MMBtu gas somewhere around $60/MWH, newer comb. cycle gas around $35/MWH, baseload nuke around $25/MWH. Since in the majority of energy markets a nuclear unit with decent capacity factor is one of the cheaper sources of power, the cost will go up.
I think of the plant/operator reacting to maintain continuity of power to... Either way I can't even fathom ACTUAL energy infrastructure.
...So you're saying that decommissioning has more of an impact on the energy market than on the generation/transmission hardware, right? Does that mean that our general energy infrastructure is over engineered for the moment (however insufficient to cope with the expanding energy consumption that accompanies societal development)?
Since I work at a base load unit, I don't care what the frequency on the grid is. I am maintaining a load on my generator and it won't go any faster or any slower than the grid. Only when there is a major power/load imbalance (main turbine is not matched to the RX) will my turbine go to manual and then try to maintain a frequency.
That's not quite correct, because:1. To pick up load, you put more steam on your turbine, which puts more torque on a rotating mass, and for a fraction of time, your excess torque changes speed to affect the phase angle of the magnetic coupling of your generator to Das Grid. Mo trons flow out. When torque equals sync'd with the grid, stable at new power output. But yes, 99.999% of the time you are at grid frequency, which brings us to your first point of2. Yes, you do care what the grid frequency is, but may not be aware why. If the grid was at 61 Hz, you have protective relaying that will open your output breaker within a couple seconds, not to mention your various mechanical overspeed devices. If the grid was 59.5 Hz, that timer is a few minutes long. Grid at <58.0 and the turbine will trip in a few seconds. Those low frequency trips are to avoid the LP turbine blade root cracking from sub-synchronous resonance. A pretty good presentation on this theme can be found at http://www.midwestreliability.org/04_standards/drafting_teams/ufls/BarryFrancisPresentation081024.pdf3. You also care about grid voltage, and more recently the grid ops guys have to care about your switchyard voltages. To state it in nuke terms, they have to care about the offsite source to your Vital Bus. For grid operators out there, thats why you have NERC Std. NUC-001-1
I think it would be better if we argued about imaginary power. Do I burn more uranium when my MVARS are higher or lower? I think I burn more uranium when my MVARS are higher. I bet that will overspeed trip many pure electrical theory guys out there
Based on this discussion..it seems as if slight demand changes in the grid (within specific parameters) could actually be identified in the monitoring of plant systems, without actually looking at grid demands..Is this correct?Grid demand to generator to turbine to steam to Rx..
Indeed... Eastern Interconnection carries about 1,000,000 MW summer peak, so losing an 800 MW unit might run ya down to 59.99, just statistical noise lost in the grass. Losing 800 MW out West would run down to 59.96 or so.
Good point. Not many know the Eastern and Western Grids are not connected.By the way, Nutty Neutron is not entirely correct. The 2003 Blackout was not a classical cascading failure. Mike
So what was the 2003 black out then? A power plant goes down. Lines near a dirt burner sagged and caused a fault. The fault caused other parts to overload and trip. There was a computer problem that made things worst. In the end it was a cascading failure.http://en.wikipedia.org/wiki/Northeast_Blackout_of_2003
- Referencing the Wikipedia sequence of events, most of which is correct -Well, the power plant trip was in about the 4th inning. Hours before that, even before the computer lockup at lunchtime....planned outage work began on one of the 345 kV lines in parallel with the Sammis-Star 345 that was the beginning of the cascade. Point being that the other two lines in parallel weer running at or above their 100% summer continuous ratings for an extended period of time. (inspiring NERC Std. TOP-007). The state estimator tool did not give a proper N-2 analysis [ there is still opportunity for anyone to make their first billion $ writing code for a state estimator that works correctly, btw ]. Anywho...the remaining lines in parallel load up and sag into the trees (vegetation management, one of the first places corporate beancounters everywhere cut back, that and equipment maintenance) and relays off as a hard ground fault. As more lines sag into the trees, the remaining lines in other loops to serve the Cleveland area carry more current, I2R builds up heat, more lines trip off. From there, the Wiki timeline is essentially correct. The point being that the Blackout didn't start as a computer glitch, a single faulted line finding a single lonely tree, one obscure coal plant tripping offline, etc. as various anecdotal stories would convey. This had several contributing root causes, well identified in http://www.nerc.com/docs/docs/blackout/ISPE%20Annual%20Conf%20-%20August%2014%20Blackout%20EPA%20of%202005.pdf
On Wiki they mentioned that they may have saved the grid if they had cut off Cleveland. How often do large areas have to be cut off for the grid? I do know that there are days in the summer where they have "orange grid risk" days. On those days, we will stop some jobs in the power house just to reduce the risk of a plant problem.
BEST DARN THREAD IN YEARS!!!!!!!!!!!!!!,...THANK YOU EVERYBODY
The watermelon greenies are also aiming their cooling tower sights on a certain INPO 3 Region IV plant as well
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