The New Publicly Owned National Power Grid ...DC?
With our Nation's Power Grid on its' last legs, we might want to consider a Northern Solution, from Friendly Manitoba, Canada.
from http://www.thecanadianencyclopedia.com/index.cfm?PgNm=TCE&Param...
Electric-power transmission lines carry power from generating plants (see ELECTRIC-POWER GENERATION) to the distribution systems that feed electricity to domestic, commercial and industrial users. Transmission lines vary from a few kilometres long in an urban environment to over 1000 km for lines carrying power from remote hydroelectric plants. They may differ greatly in the amount of power carried. Because requirements vary, many technical, economic and environmental factors must be considered when new lines are planned.
The basic modes of transmission are direct current (DC) and alternating current (AC). In direct current, the current flows in one direction only; in alternating current it reverses its direction many times per second. It is difficult to transform direct current from one voltage to another; hence, initially DC had to be transmitted at the low voltage at which it was generated and used. This fact limited its applicability: if transmission of large amounts of electricity or transmission over long distances was required, the cost of the conductor (copper wire) was prohibitive. Alternating current may be generated at a low voltage, boosted to a higher voltage by a transformer, transmitted and converted back to a lower voltage before use. Consequently, following the development of the transformer in the 1890s, most electricity was transmitted as AC.
However, DC transmission has a number of advantages and is being more widely used. For example, a DC line, requiring only 2 conductors instead of the 3 needed for an AC line, costs about two-thirds as much. Further, in DC transmission the effective voltage is equal to the peak voltage, while in AC transmission the peak voltage is 40% higher. Since radio interference increases with the peak voltage and decreases as the conductor size is increased, the DC system can carry a higher effective voltage than an AC line of equivalent size and still maintain an acceptable radio interference level. Thus, in some long lines carrying bulk power from remote generating sites, power is generated as AC, boosted to a high voltage, converted to DC for transmission, then reconverted to AC and transformed to a lower voltage for use. The cost of the converter stations at either end is offset by the lower cost of the line. An example of DC transmission is Manitoba's Nelson River line, which carries power from generating plants on the Nelson River to Winnipeg, almost 1000 km south. DC transmission is also advantageous for transmitting power through submarine cables, such as the line from the British Columbia mainland to Vancouver Island.
AC and DC can be transmitted in overhead lines or underground cables. The cost of underground cables is much greater than that of overhead lines, but this increase may be acceptable in urban areas where space for overhead lines is lacking or where aesthetics are a major concern. Transmission across bodies of water also requires the use of cables if the distance is too great to span with overhead lines.
Overhead power lines have 3 major components: support structure, insulation and conductors. Support structures can be wooden poles, free-standing steel towers or guyed towers of steel or aluminum. Glass or porcelain suspension insulators have traditionally separated the live conductors from the grounded towers. Each insulator consists of a metal cap on top and a metal pin underneath separated by the glass or porcelain insulation. These units are used to form insulator strings which vary in length depending on the voltage level and application. Several strings may be used in parallel to carry the weight of the conductors. For 735 kV about 30 insulators are used. New types of insulators have been developed using polymers; field testing and full-scale use became more prevalent during the 1980s. In the early days of electrical transmission, copper was used extensively as a conductor, but now virtually all conductors are aluminum. Each conductor is made of many strands (1-5 mm in diameter) combined to give an overall diameter of 4-50 mm. In most conductors, steel or a high-strength aluminum alloy is used for the core strands to give the conductor added strength. In a transmission line, up to 4 conductors may be used in parallel to form a conductor bundle.
Transmission voltages can vary considerably. Early in this century, Canada's fledgling power industry transmitted a few 10s of kilowatts (kW) of power over transmission lines operating at a few 10s of kilovolts (kV). Today one of HYDRO-QUÉBEC's James Bay transmission lines may carry over 2000 megawatts (MW) of power more than 1000 km at 735 kV. As the amount of power carried and the distances increased, it was necessary to increase the voltage to reduce losses and permit more power to be carried on a single line. Losses are proportional to distance and to the square of the current. Thus, for the same amount of power, if the voltage is doubled, the current is halved and the distance can be quadrupled for the same losses. Unfortunately, as voltages increase, so do costs: virtually everything must be larger and insulation problems become more complex. Electric power is generated at relatively low voltages, 25 kV or less. It must be transformed to a higher voltage for transmission, then transformed down to the distribution voltage, typically less than 25 kV. As the cost of the transformers also increases with voltage, the optimum voltage must be chosen carefully. For complex technical reasons, the use of higher transmission voltages is beneficial to the stability of the power system.
Because of the long transmission distances in this country, Canadian ELECTRICAL UTILITIES have often been pioneers in the field of transmission technology. As of 1982, Manitoba Hydro's Nelson River system, which began service in 1972, was the largest high-voltage DC transmission system in the world. In 1965 Hydro-Québec inaugurated its 735 kV Manicouagan line, thus becoming the first utility to go above 500 kV AC for transmission. Since even higher voltages will probably be needed in the future, the utilities are supporting research into transmission at voltages in excess of 1000 kV.
Author M.M.C. COLLINS
Tags: DC, Hydro, Manitoba, Power, grid, new
Views: 460
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DC_trans_nelson_river.jpg, 36 KB
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Replies to This Discussion
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Permalink Reply by neil cox on -
Nearly all of the above, seems correct, except the USA power grid is not on it's last legs. A few locations have serious problems. The power grid and power plants are vulnerable to terrorist attack. Losses can be reduced almost everywhere, but the improvements are typically very costly with payback of 20 years or more. The HVDC = high voltage direct current power lines are needed to bring the wind turbine electricity from West Texas to the East and West coast. This will help with most of the other problems that are close to the route of the HVDC power lines. I really hate to see the Federal government increase their micro managing as government rarely does anything well. The wind turbines in West Texas are the only alternative energy method that can quickly be implemented to large scale, so we should fund the HVDC power lines. I suggest the first to Tampa, Florida on and near the route of interstate 10. Neil
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Permalink Reply by Philip Smeall on -
Well, overall the majority of the US grid may not be ready to fizzle, however, the Eastern Zones, appear to be in the greatest need. One little thing about DC, and I'm not 100% on this, but I believe a DC grid may be more resistant to any solar effects upon Earth's protective Magnetic Belt/field. I think what happened to Quebec and New York, might be less likely in Northern Manitoba?
As for the Government owning it? Well not directly, perhaps?. For example ...Manitoba Hydro, is what is known as a Provincial Crown Corporation. It has had its' ups and downs to be sure, but, overall, it has served the needs of its' far North residents very well, not to mention Minnesota and North - South Dakota... I don't have a BIZ Plan in my back pocket as yet, for the "Obama" administration, however, I'm sure they might be able to come up with one, that is fair to both public and private interests alike. In addition, the same towers might support other linkages & relays, such as communication highways, for everything from Cell/sat to Internet/cable. - Attachments:
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ManitobaWindFarm.JPG, 18 KB
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Permalink Reply by neil cox on
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I'm not sure either about the reduced vulnerability of HVDC to Van Allen belt variations and other sources of EMP = electromagnetic pulse. AC power lines are typically transposed at kilometer or oftener intervals to cancel the induced voltage and also to reduce induction/eddy current losses. The transposing may be practical for HVDC to reduce the effects of EMP, but it may not be done, because, I don't think transposing reduces losses for HVDC. The increased capacitance to ground of underground and underwater HVDC power lines, does reduce voltage spikes and dips. A rechargeable battery can float on the HVDC power line, but more than 100,000 cells are required creating a reliability and maintenance problem. This would hold the voltage rock steady close to the battery.
Does anyone know if it is practical to connect 100 DC wind turbines in series to power a HVDC power line? This would avoid the cost of stepping up the DC voltage to HVDC, if it is workable. It might also reduce spikes and dips on the HVDC line. Neil
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Permalink Reply by Philip Smeall on
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Think the Dutch did something on the latter, ...part and parcel with their DC Wind Farms?
As for cosmic effects/benefits relative to DC, burried DC most likely have a pretty decent chance with regards to hardening. Plus they are more cosmetically appealing.
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Permalink Reply by DubleDeuce on -
OKAY already. Have you two FOUND any energy yet or is this just a love fest of regurgitated da da?
Ain't gonna matter none. No matter WHAT you guys decide on, we won't have the money to pay for it NOR the credit to buy it. http://tinyurl.com/da4a73 Ya MIGHT want to go HERE and read a document MORE depressing that of Phil's Vanishing Suburbia film-much of which I found to be based on a crock of da da.
I said earlier that I feared that we MAY have killed the goose that lays the golden eggs. This document seems to not only confirm it, but spells it out in spades. You need to know a bit about double entry accounting principles, bond pricing, and the role of the Fed in the national scheme to make sense of it but the part about the destruction of capital and the banks coming up short on capital much to their surprise, seems to spell it out quite nicely. A mistake of such colossal magnitude is NOT the stuff of conspirators and thief's, but rather the likes of a Captain Smith on the Titanic, foolishly forging ahead to secure the glory of being the fastest ocean liner to cross the Atlantic. As it turned out, he did momentarily hold the speed record for fastest to the bottom (soon eclipsed by the Lusitania by 2 hrs) and does hold the record for the deepest at 14,700 ft. There are just SOME things you don't need to be famous (or infamous) for.
Proper attention to the accounting ledger and a little less masturbation of the brain by otherwise reasonable CPA's and this mess could have been avoided.
Wanna know where all the capital went to? Subprime mortgages 80%- and upper management bonuses and dividend payouts the rest.
The Deuceman
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Permalink Reply by Philip Smeall on
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Sad news below, but check the big start in Manitoba;
http://www.canada.com/topics/news/story.html?id=8ae444c2-352a-4a26-...
...how to DO IT!
http://www.gov.mb.ca/stem/energy/wind/files/mb_wind_farm_developmen...
And Manitoba employs an HVDC distribution system. I say build more Wind Farms in Manitoba and the Tri State area, turning this part of North America, into one giant dynamoe of Power Generation! Then Extend Manitoba's low profile HVDC system all the way down to the Mexican Border and beyond. Adding wind farms and DC/AC converter/distribution stations all along this new North American Power Artery! Including re-establishing the Picken's Texas Dynamoe Wind Farm!
Power to the People! DO IT! America needs more that legislated stimulus packs and empty promises and platitudes. We need action. Force Energy.
================SAD but not the end! =======================
HOUSTON – Plans for the world's largest wind farm in the Texas Panhandle have been scrapped, energy baron T. Boone Pickens said Tuesday, and he's looking for a home for 687 giant wind turbines.
Pickens has already ordered the turbines, which can stand 400 feet tall — taller than most 30-story buildings.
"When I start receiving those turbines, I've got to ... like I said, my garage won't hold them," the legendary Texas oilman said. "They've got to go someplace."
Pickens' company Mesa Power ordered the turbines from General Electric Co. — a $2 billion investment — a little more than a year ago. Pickens said he has leases on about 200,000 acres in Texas that were planned for the project, and he might place some of the turbines there, but he's also looking for smaller wind projects to participate in. He said he's looking at potential sites in the Midwest and Canada.
In Texas, the problem lies in getting power from the proposed site in the Panhandle to a distribution system, Pickens said in an interview with The Associated Press in New York. He'd hoped to build his own transmission lines but he said there were technical problems.
Wind power is a big part of the "Pickens Plan," which was announced a year ago Wednesday. Pickens has spent $60 million crisscrossing the country and buying advertising in an effort to reduce the nation's reliance on foreign oil.
"It doesn't mean that wind is dead," said Pickens, who runs the Dallas-based energy investment fund BP Capital. "It just means we got a little bit too quick off the blocks."
Pickens announced in 2007 plans to install the turbines in parts of four Texas Panhandle counties.
He had hoped to complete the four-phase project in 2014 and eventually have 4,000 megawatts of capacity, enough to power more than one million homes. The total cost was expected to approach $12 billion.
Renewable energy provides a small fraction of electricity used today, but the wind and solar sectors are the fastest growing in the U.S. In 2008, the U.S. became the world's leading provider of wind power.
Like most industries around the world, the recession has hurt wind turbine manufacturers and wind farm developers. Companies have shelved development plans and laid off workers.
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Permalink Reply by Home Wind Turbine on -
The grid should be left alone to support largest industry and business. All homes should be making their own energy, or a portion of it using RoofMill technology and hybrid wind/solar. Why are we pouring money and effort into a completely centralized approach to energy. We need to DE-CENTRALIZE our power generation and take whatever resources and apply them in this way.
Americans, wake freakin' up. Can't you see that we have a new day in energy for the home, consumer, taxpayer. We now have ability to make our own power, or a large portion of it. Get energy security, energy freedom. Why let these big companies use the green energy to raise your cost and enslave you to a continuing monopoly. Wind Farms, who cares, grids, what a waste. Home Wind Turbines, wind/solar hybrid rooftop kits, now that's something worth getting into. I'm doing it. When there's a black out, I could care less, all my stuff runs anyway and I have energy security, energy freedom, and it's also improved the value of my home. Home Wind/Solar People, get your own. Have a look at my videos showing my home wind turbine system running, really cool and worth doing.
If it's got to be grids.. well some good ideas here I'm reading. But I just think losing 7% in transmission is wasteful and have an axe to grind about wind and solar being monopolized when folks can do this themselves. You don't need your utility company to do green energy.
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Permalink Reply by Philip Smeall on
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Agreed, and FARE has helped promote a lot of work in Florida on this, including ;
""FPL Group Inc's utility Florida Power & Light is working with the realty group Kitson & Partners to construct what the utility says will be the world's largest photovoltaic solar plant in a planned, environmentally friendly city near Fort Myers in southwestern Florida.
Called Babcock Ranch, the city will aim to build 19,500 houses and about 6 million square feet of retail, light industrial, and office space when it is completed, the developers said.""
You still will need large economies of scale Power Projects for industry. As the oil disappears, moving goods across oceans will become less viable and a new E-Industrial revolution will take place in the US,based on local not middle eastern energy reserves led by Coal, wind, solar and some nuclear, plus of course our limited reserves [sorry Pickens] of natural gas. [[not to mention the old, currently too expensive deep reserves of North American oil]]
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Permalink Reply by RWC1972 on -
DC is only an option if you are going to take a very large source of power and run it directly to a large load which is far away. As far as using DC for your average transmission and distribution lines it is not cost effective at this point in time.
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Permalink Reply by Philip Smeall on
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Actually there is a high effciency relatively short distance transmission project being finallized in Manitoba.
http://www.hydro.mb.ca/projects/bipoleIII/index.shtml
http://images.google.com/imgres?http://www.hydro.mb.ca/projects/rie...
So, I have to disagree. However, If you are talking about it not being cost effective only within certain urban and rural zones, then yes, of course it wouldn't be. However, for transmission systems going cross country, it is very effective. For gathering surplus Power from future Solar, H2 Gen Plants and Wind Plants, and transfering it across the North American continent, it may be the way to go. In general the longer the line, the greater the benefit of HVDC. In addition, long underground transmission projects, appear to be better served by HVDC tech..
In any case here are a few good objective articles on the subject, outlining all the benefits and draw backs. As with any tech question there is no simple right or wrong;
FREE
https://pscad.com/resource/File/Library/BasisPrinciplesofHVDC.pdf
excellent reviews, of pros and cons of HVDC;
http://nomoretowers.org/Documents/Sugarloaf%20Conservancy%20Noteboo...
http://www.scribd.com/doc/7221498/0071490191ar015
http://plainswindeis.anl.gov/documents/docs/APT_61117_EVS_TM_08_4.pdf
membership required
http://mrw.interscience.wiley.com/emrw/9780471346081/eeee/article/W...
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Permalink Reply by RWC1972 on
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(from the article you linked)
Bipole III
Transmission Reliability Project
Plans are moving forward to develop a new high voltage direct current (HVDC) transmission line, known as Bipole III, on the west side of the province. Bipole III will significantly improve the reliability of the provincial transmission system.
Identification of a route for Bipole III will be based on a Site Selection and Environmental Assessment (SSEA) process. The SSEA will begin in fall 2008 and is scheduled to take four years to complete. Regulatory approvals will be required to proceed with constructing the project. The project in-service date is 2017.
This project is anything but finalized. They haven't even performed a feasibility study (which generally comes after the SSEA process).
What you linked is nothing more than hype to get folks riled up about HVDC. It may happen, but even then the in-service date is 8 years away and as a professional working in that industry, a lot can happen in 8 years, especially on a capital intensive project like that.
(In case you missed it, I'm an engineer in the T&D industry so I kind of know a little bit about this area~)
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Permalink Reply by Philip Smeall on
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VS
Well Manitoba has run a 1000 km DC stretch running since the 1970's,... no hype intended ? just the facts Mamm : )
As for Bipole III they have been talking about it for some time, however, along with the 300 Meg Wind Farm [DC] project, these should happen.
The other thing about above ground HV AC transmission is, no body wants one in their backyard.
"(In case you missed it, I'm an engineer in the T&D industry so I kind of know a little bit about this area~)"
...and good for you SIR, MOM must be proud ! ...and I'm also sure Manitoba Hydro has a few of you working for them ...
"What you linked is nothing more than hype to get folks riled up about HVDC."
riled up ?? I don't recall screaming YEEE HAAA :O
a bit more...
http://en.wikipedia.org/wiki/HVDC
...you'll see lots of DC systems in Enviro Europe. Manitoba is a very Socially/Enviro aware Province, hence the lengthy study. I'm sure they'll build it, but really, what's the real problem? It's all just information ...
...and no I do not currently work for Manitoba Hydro.
HYPE ?!?! hey why NOT! ...you want hype already?...we got hype...
VS
In closing, here's some news/history on a subject I'm sure we can BOTH agree upon,
WIND Power;
Shell Oil and Wind Power
http://www.iht.com/articles/2007/04/18/business/wind.php
Off Shore and related Power Grid[s];
http://www.owen.eru.rl.ac.uk/documents/bwea20_46.pdf
World Stats, Wind Power;
https://www.earth-policy.org/Indicators/Wind/2008_data.htm
Wind Power and DC;
http://www.offshorewindenergy.org/ca-owee/indexpages/downloads/Brus...
...we even got Hillary yet..., and I bet she'll have the President's ear when if comes to renewing our Nation's Power Grid :)
Keep on blowing aye ?
Have a nice day :)
...Oh here's a few DC lines in Europe.
http://www.offshorewindenergy.org/ca-owee/indexpages/downloads/Brus...
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