njcommuter on July 9, 2008 at 11:31 AM

Taking it in order;

1. You’re confusing voltage and amperage. Voltage is the amount of power being transmitted, amperage is the ability to overcome resistance, R, expressed in ohms. (Ohm’s Law.) To visualize the difference, do this gedanken experiment;

Put a gallon of water in a bucket, then throw the water (but not the bucket, please!) at somebody so that it takes 1 second for the full gallon to hit them. They’ll be drenched, and probably not too happy about it unless it’s a hot day.

Now, put the same gallon of water in a high-pressure centrifugal pump (like the ones on a fire pumper) and force it through a carburetor jet off of a 1965 Chevrolet V-8 in one second. If that narrow jet of water hits someone, it can draw blood, as the pressure behind it is high enough that it will scour off skin. (Add in sand, and you have an industrial sandblaster, actually.)

The amount of water (1 gallon) is the voltage. How hard it hits (by thrown bucketful or by HP pump) is the amperage. Never confuse the two.

2. The “heat loss” you mention over long lines is the result of the resistance (R, in ohms) of the conductors in the lines (usually copper) to the amperage (not voltage) of the current. Resistance is a factor of exactly what the conductors are made of; copper has about the least of the reasonably inexpensive metals. For really low R, the Apollo spacecraft’s DC electrical system used wiring made of gold and in some areas platinum; but that’s a bit expensive for long lines and can’t take as much tension on a “sag” as copper. (To say nothing of how fast it would be stolen by metal thieves.) The resistance of even copper renders long line transmission of solar or wind-turbine generated AC or DC power dicey at best.

3. My figure for 40-50% efficiency is that quoted by NASA for the solar arrays on their spacecraft. I don’t expect that they would work as well under 20+ miles of atmosphere, even on a sunny day, as they do in hard vacuum, but I like to give the other guy the benefit of the doubt. (If his hypothesis won’t work even under ideal conditions, it certainly won’t work in real-life conditions. Caveat Emptor.)

4. Other posters have dealt with the difference between AC short-range transmission and DC long-range, which is rarely used in the U.S. (I won’t say never, as I am not an electrical engineer). DC transmission is used in other countries because they use DC current domestically, not having realized (unlike George Westinghouse over here) that Nikola Tesla had his facts a bit straighter than Thomas Edison did.

5. I was aware of the cryogenic systems feeding WTC; you find similar systems in similar applications in everything from power plants to large buildings worldwide. I was referring to the impracticality (let’s call it what it is- plain dangerousness) of trying to run long lines underground for large areas of domestic grid, through all sorts of soils with the attendant problems of ground water, shear lines, strata differentials, and traffic-induced vibration (to say nothing of the occasional burst water main), with all the lines run in insulated pipes full of a liquid which can instantaneously freeze anything it hits. The guy on the show was conspicuously silent on the subject of how you insulate such a conduit, how you deal with inevitable vaporization pressure issues (especially on a hot day- or just in Southern California on any given day), or what you make the conduits out of that will resist embrittlement by being subjected to temperatures near absolute zero for years at a time. Not to mention what happens if somebody on a city work crew accidentally hits one with a backhoe while working on a sewer line. Best guess; work crew ends up in the nearest ER- if they’re very lucky. With frostbite the likes of which is rarely seen outside of the Arctic regions, or when something goes very badly wrong at Burdette Oxygen or Morton-Thiokol. Which, fortunately, is rare due to those organizations having safety regulations and procedures virtually identical to those those used at Cape Canaveral- for exactly the same reasons, NASA being one of their biggest customers.

However you slice it, Wind and Sun just won’t cut it except in very small-area, localized applications. You can change the laws of the land, but not the laws of physics.

(Don’t look at me- I didn’t write ‘em.)

cheers

eon

Oldnuke on July 9, 2008 at 3:53 PM

Alaska is not connected to anyone. We have our own massive grid and then multiple small ones. 2 are NG grid to convertion electricity and 1 is a coal to electricity grid. And some up here run on Diesel, think about those costs…

Yeah when it comes ot the LNG pipeline that is being purposed, it is one of those things. Is the State trying to become more wealthy and not listen to the people? Is this more for those who have outside interests? Is this to stimulate the ecomony. All good questions, yet unknown as to answer quite yet.

onlineanalyst on July 9, 2008 at 4:17 PM

People are building water buildings with shallow pools to “grow” algea. It is an easy item but lets say you now have a special strain of this super algea and you walk outside with thei strain on your shoes and it gets in the dirt or another water source. Will it kill the fish, plants and animals? Will it thrive to choke out oxygen? Will it become toxic? The possibilities are scarey and endless. But this is what many are wanting via the ethanol ideals.

The algea idea is still up in the air. I am sure it would work, but at what cost? How would it work? What would happen if the algea got a virus or became diseased and stopped producing? Algea is just like a plant, it could happen!

I see an unintended consequence of using algae. Wouldn’t doing so upset the food chain for sea life? Is this another foolish idea that would jeopardize world food supplies?

upinak on July 9, 2008 at 3:41 PM

I had never thought much about utilities in Alaska, that’s why I asked. People down here are woefully ignorant about you guys up North. Like you said

Alaska: the island off the coast of Mexico in that box to the left!

Maybe you can get gas piped into Alaska. I’d say not being able to heat your home in Winter in Alaska is pretty serious. I’m all electric, don’t even have access to gas in my home. My heat pump is more than adequate for our winters here in Virginia.

Oldnuke on July 9, 2008 at 3:31 PM

Why should there be a LNG pipeline going through? There is plenty of NG down in the lower 48. Maybe it is time to get the Senate and Congress to have BLM open it up.

Besides the fact that Anchorage bowl area, Kenai/Homer area is about out of NG… we are worried about not being able to warm our houses for winter in a couple years. This is a Fact here.. not the bell curve fiction. Yet we can’t get a spur line to the cities? Something is wrong… and it smells like methane!

upinak on July 9, 2008 at 3:15 PM

I was speaking strictly about electricity. The Canadian blackout in 76 is the one that took out most of the Northeast US. Why don’t you want a natural gas line running through Canada?

cozmo on July 9, 2008 at 3:16 PM

Alaska: the island off the coast of Mexico in that box to the left!

Sometimes I feel like I am on an island.

5 grids.. but Alaska and Hawaii do not count. But then again we aren’t part of the 57 States!

upinak on July 9, 2008 at 3:01 PM

What can I say, ya’ got me there.

Oldnuke on July 9, 2008 at 3:08 PM

I don’t want to be connected Old. As I do not want a Natural Gas Pipeline to go through Canada into IL.

Depends on which black out? Canada had one in 76 but it affected you all. We had a BIG one up here (about 15 yrs ago) due to a snow storm, and it was a nasty one at that, that turned off all electricity for 3 days or more depending on where you lived in the State. I was breeding exotic Parrots at that time and lost 4 of my hand fed babies. Couldn’t keep them warm.

upinak on July 9, 2008 at 3:01 PM

Hey, I’m not sure Alaska is on a grid by itself. You may be connected through Canada. I know the lower 48 have interconnects up North. I’m digging here but didn’t that big blackout back around 76 or so start in Canada?

And it was time for refueling and refitting. They couldn’t handle newer missiles and could no longer embark helicopters.
Oh, and they were sacrificed to the “peace dividend” Lots of reasons.

Mostly it was money. At least that was what a friend of mine told me. He was one of the last captains of the South Carolina.

cozmo on July 9, 2008 at 2:53 PM

5 grids.. but Alaska and Hawaii do not count. But then again we aren’t part of the 57 States!

The last time I studied the issue, about 20 years ago, it was. I was not aware that the problems that required DC had been resolved. It would have been very simple for you to just let me know that things had changed, instead you just declared that I was full of crap.

MarkTheGreat on July 9, 2008 at 2:23 PM

I already said I was snippy and shouldn’t have barked at you.

I’m not being contentious here but are you saying that 20 years ago DC distribution systems were common? If that’s what you mean I’m pretty sure you’re wrong. DC was never widely used in this country except for things like trolleys and subways. There were a couple of utilities that had small DC subsystems but I think even the last of those was eliminated a couple of years ago.

There are still the three grids, east, west and Texas. They can interconnect. Texas makes a lot of money from California every summer selling its excess electricity to them.

Though interconnected, they are still separate grids. So much for a single attack taking out all the country’s electricity.

cozmo on July 9, 2008 at 2:19 PM

The main reason the cruisers were retired was cost of operation. It took a lot of highly trained manpower to keep those reactors operating safely. It was much more cost effective to replace them with fossil fuelers than try to maintain the staffing necessary for the nukes.

The safety record of naval reactors is unparalleled.

Only two of those applications are in areas that are in desperate need on more production. And none for California. Though the one in Utah could supply the grid.

Not sure what you meant by that. Power generated here on the East coast can be transmitted to the West coast. It’s done all the time. Texas, at one time, was the only state that didn’t have interconnects to the rest of the US. At least that’s the rumor. I don’t know if that is true today or not, or even if it was ever true. Back around y2K during a particularly bad high heat low reserve period we sold emergency power to a California utility for a phenomenal rate. We made lots of money that month.

Right now there are no nukes under construction. I think Dominion is going to break ground in 2009 or 2010. The process is supposed to have been streamlined, but like anything the government has a hand in I’m skeptical. The COL is something new though and supposedly once you get that you’re free and clear to navigate from busting dirt to going commercial. I think there are about 4 or 5 plants that have those now. I do know the one I’m most familiar with is supposed to begin Operator licensing in 2010. That’s about a fourteen month process once the class starts, probably more like 2 years since it’ll be a cold license class.

The last time I studied the issue, about 20 years ago, it was. I was not aware that the problems that required DC had been resolved. It would have been very simple for you to just let me know that things had changed, instead you just declared that I was full of crap.

cozmo on July 9, 2008 at 9:53 AM

The US Navy retired its nuclear cruisers and the gas turbine powered Tico’s took their place.

Yes they did. Do you know why?

Yes, most of the reasons, anyway. I thought the Virginia class cruisers were among the most beautiful ships of war on the sea.

I’ll concede the efficiency of the navy’s reactors. I was more concerned with their safety record.

As for the reactor applications, great…how many are under construction? Comanche Peak, the one I am most familiar with, took 16 years to build. And that was after a long battle to get the license. I hope all those applications get granted, and many more to follow. Realistically though, even with fuel costs what they are now, do you see that happening in today’s political climate? Only two of those applications are in areas that are in desperate need on more production. And none for California. Though the one in Utah could supply the grid.

Wikipedia isn’t bad for what it is. Easy to use and free. But I like to corroborate anything I get from there.

Gosh MarkTheGreat, the power of your obviously superior intellect has pierced all of my defenses. Please accept my humble apologies and go hither to joust with the Obama.
Do with him what you did with me and get him to force his fellow dems to abandon wind power and focus on something that works. The sooner the better…like now.

MarkTheGreat on July 9, 2008 at 1:46 PM

Long distance distribution is done DC because of inductive and capacitive losses.

Local distribution is done in AC because of the ease of stepping up and down.

MarkTheGreat on July 9, 2008 at 12:01 PM

There’s what you said. The way I read it is that you thought this was common. If that’s not what you meant then I apologize. You’re right I was a little cranky and I shouldn’t have snipped at you, but it was fun.

DC transmission is not common, it lost out a long time ago. It remeains to be seen if HVDC will work out.

You can disagree all you want, but let me ask you a simple question. Answer honestly. In the quote above when you made it were you under the impression that electrical power in this country was converted to dc for transmission and then re converted to AC for distribution?

I’ve was looking for links to medical waste, but oldnuke has demonstrated once again the futility of bothering.

oldnuke sure gets cranky in his old age. Perhaps senile as well.

Unless you agree with him 100%, he gets angry and calls you names.
I make a general statement that DC is used for long distance distribution.

He comes back by screaming that it isn’t used as much as it once was and that it’s used more outside the US than in.

And for this unforgiveable sin, I’m told that I’m full of crap.

Did you forget your ex-lax this morning?

oldnuke can use wikipedia, but I can’t?

upinak on July 9, 2008 at 1:32 PM

I don’t like Wiki much either but I knew it was what he was using to cherry pick his talking points from. Using Wiki is Ok for a quick link and better than just saying Hey I worked in the industry for 40 years, which I have no way of proving.

Again here’s the pertinent quote.

The longest HVDC link in the world is currently the Inga-Shaba 1700 km 600 MW link connecting the Inga Dam to the Shaba copper mine, in the Democratic Republic of Congo.

Try again Mark. We don’t use DC distribution in the USA. Worldwide it’s very limited. You’re right I have nothing to apologize for.