Good point Dave, modern turbofan engines are "high bypass" designs, where the mass flow rate through the fan may be 10X going through the core. Needless to say, they produce a lot of shaft power to drive the fan.
There are two general flavors for combustion turbines, 'aero-derived" and industrial. The former as the name implies are derived from jet engines and are typically somewhat less efficient than industrial turbines due to need to minimize size and weight. Aero-derived turbines are typically quicker to bring on-line and designed for higher number of start/stop cycles.
And are not most subsonic "jet" airplalnes really Turbojet or Fanjet, using a combination of jet action and fan action to produce thrust?
tdmidgetVitually evry utility has combustion turbines in their fleet. They are NOT "jet" engines. "Jet" engines produce thrust in reaction to their exhaust. Combustion turbines, turboshaft engines, whatever appropriate name is applied do not produce thrust. They produce torque applied to a rotating shaft that transmits that rotation to a generator in this case or compressor, propellor, rotor blades or whatever. Ad
After the 1965 New York City blackout, the utility I worked for installed some quick start peaker plants. There were two types, Single shaft gas turbines and two shaft jet engine driven turbine plants. These were a lower cost design based on off the shelf airplane type jet engines exhausting into a separate turbine which was coupled to its generator. Lower initial cost, but higher operating cost. They had a limited operating time and were next to last on the list for dispatch. Burned J4 fuel and there primary justification was for system black start capability. We also installed one set (five units) of EMD 567 diesels at one of our fossil plants for black start capability and peaking power. Last on the dispatch list. Eleven megawatts total output. The diesels and the jets are all gone now.
rdamonThere is a lot of investigation into the use of 220V DC or higher to eliminate the inverter power loss.
The UPS for the computer center I worked in took in 3 phase 480VAC, rectified it to something like 400VDC, ran that across a large bank of batteries, then inverted it back to 480VAC 3 phase.
It used what amounted to 12VDC deep cycle batteries, but there were a lot of them...
Or did I already say that?
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
rdamonJust ask Delta airlines how important it is not to lose power to a primary datacenter. It is an interesting trend in telecommunications to see how things have evolved from using -48V DC power with at least 8 hours of battery support to driving servers with 220V AC and an inverter with less than one hour of battery time (some locations use large flywheels instead of batteries). Designing datacenters to have redundant commercial power feeds off of different grids and the increased reliability of generators and transfer switches have allowed for the reduction of the large lead-acid battery rooms from the Bell System days. There is a lot of investigation into the use of 220V DC or higher to eliminate the inverter power loss.
http://www.icelanddatacenter.com/#whyiceland
Never too old to have a happy childhood!
rdamon A few municipal electric organizations in Georgia installed some gas-turbine (generator driven by a jet engine burning natural gas) peaking units that operate when demand or costs rise above their operating costs. Interesting link on how much it costs to generate electricity. http://www.eia.gov/electricity/annual/html/epa_08_04.html
http://www.eia.gov/electricity/annual/html/epa_08_04.html
Vitually evry utility has combustion turbines in their fleet.
They are NOT "jet" engines. "Jet" engines produce thrust in reaction to their exhaust. Combustion turbines, turboshaft engines, whatever appropriate name is applied do not produce thrust. They produce torque applied to a rotating shaft that transmits that rotation to a generator in this case or compressor, propellor, rotor blades or whatever.
rdamonA few municipal electric organizations in Georgia installed some gas-turbine (generator driven by a jet engine burning natural gas) peaking units that operate when demand or costs rise above their operating costs.
I've heard of large "server farms" (data centers) running their operations on such machines. Don't know if it's cost or the fact that they don't have to rely on the grid. If one of them goes down, a lot of email and credit cards won't work...
Coal's decline as a fuel source for electric generation is also due to economic considerations. As long as the price of fuel oil and natural gas remains low compared to coal, utilities are not going to build coal-fired plants..
[quote user="CandOforprogress2"]
Power has to come from somewhere and you cant put windmills and Hydro everywere. Nothi
CandOforprogress2 Power has to come from somewhere and you cant put windmills and Hydro everywere. Nothing beats coal for BTU.
Power has to come from somewhere and you cant put windmills and Hydro everywere. Nothing beats coal for BTU.
Coal is also an extremely large potential source of energy. Known coal reserves far, far exceed those of gas and oil. Coal could provide all our energy needs for centuries.
The problem of course is that coal is pretty nasty stuff. Apart from giving off more carbon dioxide per unit of energy than natural gas, it contains heavy metals such as mercury.
There are two technologies under development which if used in tandem, could make coal a clean source of energy: Underground Gasification of Coal (UGC) and Carbon Capture and Storage (CCS).
UGC consists of drilling two boreholes into a deep coal seam, igniting the coal around one borehole and pumping in air or oxygen and steam. The coal is converted to a mixture of carbon monoxide, hydrogen, methane and other gases and removed through the second borehole.
The gas produced could be converted to hydrogen, the carbon dioxide produced in this process separated off and interred using CCS.
The technique could be used to obtain energy from thin seams very deep underground, i.e. coal reserves that have never been worthwhile to mine by conventional means.
Ash along with nasties such gas heavy metals stays underground.
CCS puts carbon dioxide underground, in shale formations for example. The voids left after UGC could be used for CCS.
Together UGC and CCS would produce nice clean hydrogen. Perhaps obituaries for old King Coal are a little premature.
A lengthy article on advances in battery research. Science
C&NW, CA&E, MILW, CGW and IC fan
RockeaterClean air silliness?
BoydIf we are so bent on ending the consumption of coal and oil why do local towns and cities have ordinances against back yard wind generators? Theoretically I could run my Lionel layout from wind power,,, that is when the wind blows.
I suspect it's a clash/disconnect between idealism (getting rid of coal) and NIMBYism.
Otto von Bismark's quote almost answers the question: "Laws are like sausages, it is better not to see them being made."
People want electricity available for their many devices, but don't want to see it made... It's OK if it comes from that magical, mythical "someplace else..."
Modeling the "Fargo Area Rapid Transit" in O scale 3 rail.
D.Carleton But the residential rates are still regulated.......
But the residential rates are still regulated.......
Texas began deregulating most of its electric utilities in the 1990s. Today, as a result, the majority of Texans can choose a service plan that best meets their needs. State wide rates range from 5.8 cents per kWh to 13.4 cents per kWh, depending on the plan's features.
The residential rates for most customers served by the investor owned electric utilities in Texas are not regulated. They are driven by the market.
The rates of the state's public power and co-ops are still regulated. It is one size fits all. These entities had the option to participate in the state-wide competitive market, but most of them chose not to do so. Government owned and operated entities just don't like competition, I suspect, because deep down where they live they know that they would get blown out of the water by market oriented competitors.
Generation in Texas has been deregulated. As a result the state has seen a significant growth in merchant plants and co-generation.
The transmission and distribution systems, irrespective of ownership, are still regulated by the Public Utility Commission.
Rio Grande Valley, CFI,CFII
Paul_D_North_Jrhat grid has never gone down entirely -
A satellite image widely circulated after one of the big northeast blackouts purported to show the entire area in darkness.
A little editing and playing with contrast levels of the image showed that someone had gone into the image and blacked out large areas with an image editor.
We have a number of municipal systems around here - none of them usually are down when the big blackouts occur.
You're welcome, Norm.
The PJM (Penna. - Jersey - Maryland) grid (started 1927) is based on providing power for the original PRR electrification (announced 1928 - https://en.wikipedia.org/wiki/Pennsylvania_Railroad#Pennsylvania_Railroad_electrification ) which ran through each of those states (plus Delaware) from Wash, D.C. to New York City, though that relationship is rarely stated. I believe it has the most robust infrastructure and the best performance of any such RTO Regional Transmission Organization. To the best of my knowledge, that grid has never gone down entirely - or even mostly - in any of the major blackouts in the NorthEastern US. That includes the first major one - New York in 1965, and then the 2003 one:
http://blackout.gmu.edu/events/tl1965.html
https://en.wikipedia.org/wiki/PJM_Interconnection#The_Northeast_Blackout_of_2003
http://pluggedin.pjm.com/2013/08/the-2003-blackouts-effect-in-perspective/
https://en.wikipedia.org/wiki/Northeast_blackout_of_2003#Unaffected_regions
See also the 1st 47 slides of this presentation (includes international blackouts):
https://www.pjm.com/~/media/training/nerc-certifications/sr-systemrestoration.ashx
I believe that results from its heritage as a PRR progeny, which placed primary importance on reliability and efficiency.
http://www.pjm.com/about-pjm/who-we-are.aspx
http://home.engineering.iastate.edu/~jdm/ee553/PJMmarket.pdf
Today, PJM seems to be the leader in terms of technology and innovative programs to better manage and improve all aspects of electrical transmission:
http://www.pjm.com/about-pjm/emerging-technologies.aspx
- Paul North.
P.S. - I have no financial interest or other relationship with PJM other than being an ordinary consumer of electric power through one of the utilities that is a member (PPL Electric Utilities, Inc.).
Thanks for the continuing education Paul. The 2003 blackout left people wondering why it took so long to get everything back on line. Now I know.
Norm
The Safe Harbor, PA hydroelectric dam is tasked with being able to achieve a 'black start' in the event of a widespread power outage in the Northeast. One of those units is set up for 25 hz. Some of us will recognize the significance of that* without looking - see:
https://en.wikipedia.org/wiki/Black_start
http://www.liquisearch.com/amtraks_25_hz_traction_power_system/power_sources/hydroelectric_generators - 2nd para.
http://www.shwpc.com/facts_figures.html - * at bottom of page.
http://www.pjm.com/~/media/training/nerc-certifications/gen-exam-materials/gof/20160104-black-start-definitions-procurement-process.ashx
http://www.rtoinsider.com/pjm-black-start-replace-coal/
We need a chemist or chemical engineer to chime in here. What are is the various power densities of all kinds of batteries. That would be per cubic CM. Inch. foot. yard. meter. Also what is the heat loss per unit of power that would need ventilation to dissapate the heat ?
EMD made units that were for "PEAKING" and "BLACK START" use back in the 60's. Commonwealth Edison bought these after the New York Blackout of 1965 for their Joliet, Fisk, and Waukegan, stations. They were in blocks of 5 and each consisted of a 2 MVA generator driven by a 567 diesel plus a switchgear module providing a total peak output of 11,000,000 Watts. They were the last units dispatched since their fuel and maintenance cost was about $0.20 a KW when the customer charge was about $0.08/kW. They were quick to come on line. Their primary justification was the need to be able to recover from a system blackout. Or to recover from the loss of a major generator. How do you start a fossil or nuclear plant without the energy from the network? Chicago has little hydo (too flat) and thus the diesels were a good option. But they are not economical for base load. Back then, coal generation for new units was less than $0.01 a kW at the generator. Electic utilities have the need to match the generation to the load which is lowest at night and peaks during the day and then hits it's highest peak on the hotest day of the year. And if its an extended heat spell, the peak gets higher each day. The initial cost of the diesel peakers is lower than a coal plant but the fuel cost is (was) higher. So these units only saw service on a few days of the year.
Euclid D.Carleton Electric rates are regulated and the regulators would not allow higher rates that would have brought newer more efficient generation. Why does newer, more efficient generation require higher rates?
D.Carleton Electric rates are regulated and the regulators would not allow higher rates that would have brought newer more efficient generation.
Why does newer, more efficient generation require higher rates?
The power generation world is very much like railroading prior to Staggers; the negotiated residential rates covers the cost of generation and transmission but not much more. That's the trade off: guaranteed income for a set rate. But this also makes the ratepayer a stakeholder in the power provider so when new generation needs to be built the money comes usually from selling bonds which are backed by a rate increase. In the meantime the power plants get by with minimum investment and as-necessary maintenance.
Editor Emeritus, This Week at Amtrak
There're 292 surplus UP locomotives being stored in the Arizona desert, per another thread . . .
Say 4,000 HP each average x 0.75 KW per HP = 3,000 KW = 3 MW per locomotive; 292 x 3 = 876 MW.
Some place I read that a typical coal-fired plant is around 600 MW; the infamous Three Mile Island Nuclear Generating station in PA is 802 MW:
https://en.wikipedia.org/wiki/Power_station#Typical_power_output
So those locomotives could be ~1.5 coal plants or <~1 nuclear power plants.
More than I would have thought !
And, their start-to-full power time - "dispatch time" or response time - is nearly instantaneous, probably faster than any other source except hydro.
This has been done from time to time - one I recall is the ice storm in upper New York and eastern Canada in the late 1990s:
http://cs.trains.com/trn/f/111/t/194245.aspx
https://en.wikipedia.org/wiki/MLW_M-420#Service_as_power_generators_in_Winter_1998
http://www.trainorders.com/discussion/read.php?2,409992
One problem is that the throttle setting that produces 60 hz electricity is like notch 5 or 6 - less than full rated power. But if this was ever to be done, somebody would have to figure out a way to convert or smooth the variations in frequency to match the grid.
Interesting mid-level technical explanation: http://instituteforenergyresearch.org/electricity-generation
Also: http://www.caiso.com/outlook/outlook.html
Just an observation, if one lives in an area where the electric grid is predominently burried, there can be fewer disruptions... The town here buys power from 'the grid' ,and re-sells it to the residents. (They also operate a back-up generation facility) ... Have considered a personal power back-up, fueled from natural gas; Cost on that is about $2.5 K installed(?).. So far costs, and reliablilty have not been enough of an issue to have warrented that.
The battery technologies have improved mightily, but some types, as another poster mentioned create other problems: high heat, and other issues around flamibility cause them to be banned on some air transportation. The lead-acid batteries are also equipped with their own issues, as are the 'standard' carbon based,'disposibles' batteries (AA,A, B,C, etc).
WE also have a number of "wind Farms" around this area, most of their output seems to be purchased outside the State (Ks.), but it still must be transported overland to those purchasers. There is one nuclear plant in the S.E. part of the State, and for the last few years there has been a 'Battle' between the State, a Provider, and the 'NIMBY'/'ENVIRO' crowd over a coal fired plant in SW Ks. Not sure where that stands now?
Possibly, IF the railroads could figure out how to get their excess generation capacity from their locomotives to "The Grid" they might have an answer??
BaltACD Euclid D.Carleton Why does newer, more efficient generation require higher rates? You don't expect monopolys to do the investing in more efficient generation and transmission equipment without passing that on to the consumer. [/sarcasm] Maybe consumers should have recipricol switching? (the BS that passes for deregulated electrical suppliers doesn't pass the sniff test)
Euclid D.Carleton Why does newer, more efficient generation require higher rates?
D.Carleton
You don't expect monopolys to do the investing in more efficient generation and transmission equipment without passing that on to the consumer. [/sarcasm] Maybe consumers should have recipricol switching? (the BS that passes for deregulated electrical suppliers doesn't pass the sniff test)
My point was that we are not headed for more efficient generation. We are headed for green generation, which has an added purpose besides providing power for people to use. That added purpose is to eliminate fossil fuel generation in order to save the planet. Saving the planet adds to the cost of generation because it requires the banning of the cheaper fossil fuel generation.
I don't follow your point about power companies being monopolies. It is regulation against coal and gas that will cause rates to rise.
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