[Rematog]

One simple reason for not stacking units. Real estate, esp in the country, is cheaper then structural steel. Think about the structural steel need for a 20 story (10 module) high power stack. Thats about the height of our boilers. They sit on an 11′ (yes, feet, that’s not a typo) thick concrete slab and the main columns have flanges about 2″ thick, somewhere around 200 lb per foot WF beams.

Land is cheaper. Plus, you’d need cranes, elevators…all those things equal dollar signs.

Two reasons boilers go up. Hot gases rise and molten slag falls.

Plus, until about 1960, all boilers were natural circulation. It’s only been since the 90’s that supercritical once thru boilers became common. And for natural circulation (of the water in the boiler tubes) the tubes must go up and down with the steam drum on the top of the boiler.

Gravity, you’ve got to love it, it never fails and costs nothing.

Rematog

[Rematog]

On type of plasma touch is a cutting machine used in metal working. It uses an arc to heat an inert gas to extreme temperature. It is of great use in working with stainless steels, as a conventional oxygen-acetylene torch will not cut them. This is because an oxy-acetylene torch heats carbon steel to high them, then a rich stream of pure oxy “burns” the carbon steel away. Stainless won’t burn in this way, and the oxy-acetylene flame is not hot enough to really cut stainless. See plasma cutting in wikipedia, it looks to be a good article.

At this time, there is also a firm (or more then one, not sure) that is touting a plasma arc for use in energy generation. The idea is to gasify the “fuel” with an arc in an inert gas environment. Then the resulting fuel gas can have sulfur and other undesirable constituents removed. The fuel gas can then be used in a gas turbine/combined cycle power plant. This is essential an alternative to more “conventional” (but still not really commercial) thermal gasification technologies. The advantage is the the plasma arc works in inert gas, so the oxy free fuel gas is easier to clean and a low grade fuel, such as waste product can, in theory, be used. The draw back, in addition to being an unproven technology, is the large amount of electrical load for the plasma arc.

[Rematog]

Aeronaut,

You may be right that I’m on the high side on duration, but again, I could be on the low side of parts costs…..? I cetainly don’t have hard data. But, we’re nit picking the numbers, and the point was the order of magnitude. For exampe, if maintenance is only 60% of what I guesstimated, then cost per household would go from $200/month to $150/month. A nice savings, but not revolutionary.

And, I can see FF as revolutionary… but that it does not REQUIRE distributed installation to acheive this revolution. Which is good, as I think the regulators and/or public would be NIMBY to any nuclear reactor….and fusion is a nuclear reaction.

On another note, I don’t see utilites as providing core rebuilds. If this was done in a shop (nice thought there Aeronaut!), I’d guess it to be more likely factory offered or specialy technical companies. Utilites are regulated public business’s, with very high barriers to doing work in the un-regulated arena.

Rematog

[Rematog]

Brian,

I’d be glad to know from someone (Dr. Lerner?) what the expected maintenance cycle is, but in my posts from May, 08, no one challanged this. In that post (for a central station repowering, I also used 10 shifts for duration of annual overhaul. In that analysis, I assume day & night shifts. In this case, I assumed only day, as having night shifts in a remote location might even yield negative productivity. Note the costs above are for well paid ($25-$40/hr) skill craftsman. These costs also include money for estimated parts and materials. My judgements on the costs, wage rates, durations, are based on >25 years in heavy industrial maintenace and engineering experience. Yes, I know, “appeal to authority”….. but jeez, I have been doing this work since Reagan’s first term…

Cost. The 300K to 500K figure put out by the FF developers, is for a module, FOB the factory dock. It does not include foundations, cooling, controls, fences, etc. So I’ve consistantly used $1,000K. This is dirt cheap. FF at $200/kw capital and no fuel cost, vs new coal plant at about $1,600/kw to $1,800/kw, with large fuel cost. Fission now has construction cost of $2,358/kw, as estimated by the Congressional Budget Office in May 2008. My personal belief is that that is low and would be more in the range of $3,000 to $5,000/kw. So, $1,000,000 for 5 MW ($200/kw) is cheap!

[Rematog]

10 million @6%

30 yr amortization = $719K/yr
20 yr = $860K/yr
10 yr = $1,332K/yr

10 million @8%
30 yr = $881K/yr
20 yr = $1,004K/yr
10 yr = $1,456K/yr

The above does not take into account taxes, depreciation, profits(?).

I’d also point out that the quick cost of power I did earlier today did’nt include any overhead for administration, insurance, profit, etc.

Rematog

[Rematog]

Aeronaut,

Very interesting analysis. Now your getting a feel for “obligation to serve”, which is what a regulated utility has to it’s customers (the utility takes on this duty in exchange for the regualated monopoly status).

Not mentioned in this is the added cost per house to “own” their own power supply. If the FF module, installed on site, costs $1,000K, and the distribution system to these 100 homes costs $500K to install, that adds $15k to the construciton cost of each of these 100 homes.

I went back to a cost of power I’d work up in an old post, and maintenance for a FF module (1 day every 4 weeks + 2 weeks/year, I’d be glad to post if you’d like) @$119,240/year. Now, as this is being done in field, rather than a centralized plant site, multiply this by 25% (time to drive to site each day, cost of vehiles, and crafts being less well supervised) = $149,000 per year / 100 homes = $1,490/year. Plus, you have to have a back-up power supply (the Grid?) for those 24 days per year. (12 of the days would only have about 8 hrs down time so it works out to about 96% availablility, not a bad number at all).

With a cost of money of 6%, the capital investment costs + maintenance costs: $15K@6%= $900 + $1,500 maint = $2,400/yr or $200 Month.

While not a huge electric bill, this does not seem to me to be the “cheap power” the board is assuming.

WHY?

Because, the 5MW module is being sized for peak load which was done so it could be DEDICATED to a DISTRUBUTED location. The grid allows the central station to keep it’s units much more evenly loaded, so they actually generate a much larger percentage of their rated capacity.

So, Aeronaut, your example, to me, provides another arguement against distributed generation. (and I’ll not even discuss the “keep the kids from jumping the fence” safety issue.)

Rematog

[Rematog]

The FF module needs to be able to crank out 5MW 24-7, 365 per year, for 20 years, with only planned maintenace shutdowns, 95% of the time or better.

That’s how the, what 100,000 modules, needed to replace the existing power plant fleet needs to designed if it is to do what existing coal/fission/gas/oil plant do. (except we design for 30 years and expect to get >50 years service).

Most will be cycling between 100% and 50% capacity on a daily/weekly/seasonal load demand curve.

Why is the goal cheap distributed power? Why not just cheap power? Let the market and engineering experience (once we get some with FF, so Eric, when can I buy 100 modules?) determine if distributed is cheaper, and how centralized (or decentralized) the modules should be. I’ve never been convenced that un-attended operation will happen in the normal power market, for at least 20, more like 40 years. (of course there will be special cases, miliary apps, etc wher un-attended operation may be used).

[Rematog]

An example of the dangers of an “untrained” workmen. The following is from an article in the online version of “Electric Light & Power” dated June 9, 2009. The same “ingenuity” in someone working on very high Kva power could easily be fatal.

Enjoy,

Rematog

I was on a business trip to Dallas and happened to look out of my hotel room window. I observed a group of workers cleaning the side of a building across the parking lot. It was obvious the workers were clueless to the danger they had placed themselves in.

The challenge for these workers was the distance between the parking lot and the building to be cleaned with a pressure washer. Add to this the need to raise and lower the worker operating the pressure washing wand. We often talk about human ingenuity. Well, workers can be quite innovative and get the job done yet put themselves in a precarious situation without even recognizing it.

These workers had parked a mobile scissor lift in the parking spaces parallel to the sidewalk and the building. The building was approximately twelve feet from the scissor lift. Employing a two by twelve wood board about sixteen feet long, they lashed one end to the floor of the scissor lift. This resembled a diving board, if you can imagine. Being astute innovators of equipment, they positioned three large workers as counter balances to hang on the outside of the guardrail of the lift. Being safety minded the employee with the wand in his hand was standing at the end of the “diving board” wearing fall protection that was clipped onto the basket of the lift twelve feet away (and yes, I am sure the lanyard employed a de-accelerator). Got the picture?

Being a studious safety professional, I quickly went downstairs and walked toward these hard working, creative gentlemen. As I approached, I said, “I am not with OSHA, but as a certified safety professional it is my duty to stop your operation.” They all got wide-eyed. It was obvious that they heard, “OSHA” and misinterpreted. They stopped working abruptly so I assume they knew their behavior was unsafe. When I asked who was in charge, one of the workers ran through a door and quickly produced the supervisor who was very cooperative.

The supervisor explained that it was his idea to use the innovated contraption until the rental company delivered the snorkel lift (expected to arrive on site in the next two hours). After a few minutes of discussion with the supervisor and the workers they realized the consequences of their behavior could have been serious. We all shook hands and agreed that they would wait until the rental company showed up with the proper equipment and I promised to not write them a citation (they still thought I was with OSHA). It was just another day in the life of a safety professional.

[Rematog]

I’d assume 2 modules per acre, plus a couple of hundred acres for cooling towers, switchyards, office, maintenance, and warehouse bldgs and site “buffer”.

The plant I work at, (3x 575MW coal) sits on 2,000 arces, with about half of that in use, the rest is leased to a farmer and is for any future expansion.

Rematog

“Think big, really big, then double it….”

[Rematog]

Aeronaut,

No.

Rematog

[Rematog]

We use isophase buses for generator output (at 25Kv). Big copper bars inside an insulated conduit. A system like this would be likely. I’d think it would be more linear, like a trailer court, with an access road with FF modules along it, and a back “alley” with power, control, cooling water, etc. services in a “duct bank” along the rear, with the “back” of two rows of FF modules up againt it. At the end, the main service building with tranformers, DCS system (controls), Control room, cooling water pumps, etc. Like so:

M M M M M M M M M M M M .Control. M M M M M M M M M M M M
–duct bank——————–Building—————duct bank——-
M M M M M M M M M M M M …here…. M M M M M M M M M M M M

The M’s are FF modules.

But, again my point is that INSIDE the FF module, you will have large conductors and big, heavy switchgear, etc. I just want people who havn’t dealt with this kind of thing to get an idea of what it’s like. Your run of the mill residential/commerical electrican could easily kill himself trying to work on this stuff. It take proper training and tools to do so.

Rematog

[Rematog]

Aeronaut,

I’m discussing the FF modules power conditioning, cables etc. INSIDE the module.

LOL, A station tranformer yard would need 25 Modules (or a whole lot more, in our case 115 modules) to power it.

My point in these posts was that the board seems to be invisioning pencil sized cables and shoe box sized power conditioning modues inside the FF skid. More like wrist thick cables and desk sized modules.

Rematog

PS: Google “arc flash video clip”. I personally know two men who had “died” until revived by CPR and were crippled by their burns in two seperate arc flash accidents. Look at “High voltage arcs and sparks” and “Arc flash while racking a breaker”. Remember guys, we are discussing deploying >100,000 FF modules that will have many 10’s of thousands of men and women working in them. The power industry uses big, heavy equipment (expensive) for, amoung other reasons, the desire to send it’s employees home alive at the end of the day.

[Rematog]

Aeronaut,

My bad…. you’ve quoted my un-proofed post. I’d divided 11,900 Kva by 480V, instead of the correct 0.48 Kv so that should have read 25,000 amps… I’ve corrected my post now.

At your desired 13.2 Kv, that would be about 900 Amps.

Yes, I am ignoring power factor or AC power correction.

Rematog

[Rematog]

Aeronaut,

When you talk about this, I get the idea you are picturing typical power conditioning etc. equipment. Remember, we are talking about a 5MW machine, that’s 5000 KVA…..oh and thats just the Net output. Just a quick thought, if you are getting 42% net (I think I’ve seen this figure used), then:

5000KVA / 42% = 11,900 KVA Gross, So, 6,900 KVA is thus the input power. I don’t know what voltage we’re looking at, but a typical industrial voltage is 480V. So 11,900 KVA gross is abot 24,790 amps at 480 V.

Hmm…. that’s got to be wrong, no way an electrode would survive that amperage. Say you’re using 10,000 Volt (10Kv) power, so thats 11,900 KVA / 10 KV = 1,190 amps. You get the picture.

I’ve seen the cables used for a 2000 HP 3 phase 6,900 V motor. That requires over 200 amps and the three cables are wrist thick (lots of insulation on a 6,900 volt cable). (2000 HP / .75 Hp/kw /6.9Kv / Square root of 3 (3 phase AC) /95% (eff) = 235 amps)

Eric, are my back of the envelope calc. of the net, gross and input powers for a FF module in the ball park?

Rematog

[Rematog]

Brian,

Did you take into account the cost/lifespan of the battery pack? After what, 3-5 years, you will need a new one. My 2001 S-10 does not need a new gas tank yet, and if it did, it would cost a lot less then the >$10K figure I’ve seen as GM’s cost for the Chevy Volt’s battery pack (and I doubt they’d sell it at cost :-{O

Rematog

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