RE: An interesting response
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Charlie Bell Sent: Saturday, May 03, 2008 9:48 AM To: Killer Bs (David Brin et al) Discussion Subject: Re: An interesting response On 04/05/2008, at 12:31 AM, [EMAIL PROTECTED] wrote: The second article shows a _demostrated_ range of 13500 for the 777 , and the nonstop route would be somewhat shorter than a one stop route. When loaded with passengers and baggage, the airline will be able to fly 10,900 miles non-stop Yes, it did 13,500. Unloaded. It'll just be able to do London - Sydney loaded if the shortest possible aircraft route is available, and in the right conditions. Really want to rely on no headwinds to make it across Oz...? The longest scheduled commercial service offered currently is the over 18 hour non-stop from Newark to Singapore. Maybe someone will offer a London-Sydney non-stop in the future, and maybe it'll be a 777 that does it, but currently no plane can do it commercially, as I said. First a pedantic point, than a real one. You actually said No current commercial aircraft can do it. The sources I read indicated (I think I quoted one) said that Boeing was in negotiations for selling a number of 777s configured to make the London-Sydney run nonstop, on a regular basis. The return trip, due to prevailing head winds, would require a stop. The change to the plane would be a seating arrangement change, from 300 seats to 250. Clearly, this is not commercial now, or someone would be making money doing it. But, a commercial plane is capable of the trip, which is what I honestly thought we were discussing The more substantial point involves the maximum speed achieved by piloted planes over about the last 60 years. 1947312 1968925 19901000 20081000 There is physics behind this, not just a lack of will. _That's_ been my point all along. Dan M. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: An interesting response
At 05:34 PM Monday 5/5/2008, Dan M wrote: The more substantial point involves the maximum speed achieved by piloted planes over about the last 60 years. 1947312 1968925 19901000 20081000 There is obviously some additional modifier missing here, since even if the X-15 is disqualified since it used a rocket engine rather than an air-breathing engine, the SR-71 is still considered a jet aircraft (even if it uses exotic fuel) and is piloted (http://en.wikipedia.org/wiki/Eldon_W._Joersz). . . . ronn! :) ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: An interesting response
Original Message: - From: Ronn! Blankenship [EMAIL PROTECTED] Date: Mon, 05 May 2008 19:22:53 -0500 To: brin-l@mccmedia.com Subject: RE: An interesting response At 05:34 PM Monday 5/5/2008, Dan M wrote: The more substantial point involves the maximum speed achieved by piloted planes over about the last 60 years. 1947312 1968925 19901000 20081000 There is obviously some additional modifier missing here, since even if the X-15 is disqualified since it used a rocket engine rather than an air-breathing engine, the SR-71 is still considered a jet aircraft (even if it uses exotic fuel) and is piloted (http://en.wikipedia.org/wiki/Eldon_W._Joersz). Sorry, I was doing meters/second and didn't give units like I meant to. 1000 comes out to 2236 mph, a bit more than your source which claims 2188. Maybe the 2236 wasn't quite official for some reason. But, we basicaly agree here. And yes, I didn't consider rocket planes, and didn't consider the shuttle, etc. Dan M. mail2web.com - Microsoft® Exchange solutions from a leading provider - http://link.mail2web.com/Business/Exchange ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
Dan wrote: My argument is that we shouldn't think of green energy as merely a test of our will. It is also dependant on the lay of the land. Past behavior doesn't guarantee future behavior, but it's much more likely that, in 10 years, we will have a 1 terabyte drive for $100 than have a plane that can carry 1500 passengers that flies for the same price (not price per passenger but total price) as a plane that carries 100. 10 years? You can get one for $200 now: *http://tinyurl.com/62bmep The way prices for hard drives change, I doubt it will be much more than one. Doug * ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
Original Message: - From: Doug Pensinger [EMAIL PROTECTED] Date: Sun, 4 May 2008 11:10:57 -0800 To: brin-l@mccmedia.com Subject: Re: An interesting response Dan wrote: My argument is that we shouldn't think of green energy as merely a test of our will. It is also dependant on the lay of the land. Past behavior doesn't guarantee future behavior, but it's much more likely that, in 10 years, we will have a 1 terabyte drive for $100 than have a plane that can carry 1500 passengers that flies for the same price (not price per passenger but total price) as a plane that carries 100. 10 years? You can get one for $200 now: *http://tinyurl.com/62bmep The way prices for hard drives change, I doubt it will be much more than one. I stand corrected. :-) How about 10 Tbytes in 10 years for $100? I suppose that might seem expensive in 10 years, unless there is a lot of inflation between now and then and the minimum wage goes to $100/hour. When I first looked at the price of disk space, in 1978, the HEP department was paying $2.50 per week per Mbyte for its use of disk space. So, it's fair to say that I've understated my point. :-) Dan M. Dan M. mail2web - Check your email from the web at http://link.mail2web.com/mail2web ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
Original Message: - From: Charlie Bell [EMAIL PROTECTED] Date: Sat, 3 May 2008 15:17:39 +1000 To: brin-l@mccmedia.com Subject: Re: An interesting response On 03/05/2008, at 1:48 PM, [EMAIL PROTECTED] wrote: and their fuel loads per passenger. One would have to stop for fueling several times to make that distance. I realize that most planes have to stop once, including the 747, but the 777 can make it in one. London to Sydney? In one hop? No current commercial aircraft can do it. London to Sydney is almost 13.500 miles and the 777 has a range of a bit over 9000. I'll come back to the rest of the post later. It's true that some of the plans are for 787 flights, not 777 flights, but if the links given below are trustworthy both the 777 and the 787 have the capacity to do it as nonstop. http://www.get-packing.com/news/flights/archives/april-2007/virgin-plans-dir ect-london-to-sydney-flights.html?fid=1094933108 http://travel.timesonline.co.uk/tol/life_and_style/travel/business/article59 0535.ece http://www.get-packing.com/news/flights/archives/february-2007/qantas-consid ers-non-stop-london-sydney-flights.html?fid=1638842198 It's not commercial yet, but according to the first quote, planes are now on order for that flight. The second article shows a _demostrated_ range of 13500 for the 777 , and the nonstop route would be somewhat shorter than a one stop route. Dan M. mail2web LIVE Free email based on Microsoft® Exchange technology - http://link.mail2web.com/LIVE ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
On 04/05/2008, at 12:31 AM, [EMAIL PROTECTED] wrote: The second article shows a _demostrated_ range of 13500 for the 777 , and the nonstop route would be somewhat shorter than a one stop route. When loaded with passengers and baggage, the airline will be able to fly 10,900 miles non-stop Yes, it did 13,500. Unloaded. It'll just be able to do London - Sydney loaded if the shortest possible aircraft route is available, and in the right conditions. Really want to rely on no headwinds to make it across Oz...? The longest scheduled commercial service offered currently is the over 18 hour non-stop from Newark to Singapore. Maybe someone will offer a London-Sydney non-stop in the future, and maybe it'll be a 777 that does it, but currently no plane can do it commercially, as I said. Charlie. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
Charlie Bell wrote on April 16th: Re: An interesting response On 17/04/2008, at 12:26 PM, Dan M wrote: Well, Concord was a political animal from the very beginning wasn't it? It was a tax subsidized showcase for Britain and France from the start. IIRC, it never really was a profit center. All aircraft mfrs are subsidised. Yes, it was supposed to be a technology It sounds as though this is a reflection of the common EU argument that the USs concentrating its purchases of military aircraft amounts to a subsidy of US commercial aircraft. But, the big US commercial aircraft maker (Boeing) hasnt had much luck in the military marker in the last 15 years. Boeing has received tax breaks, like every company, but the governments are not involved the way the EU is involved with AirBus. its successor would have been an efficient supersonic plane. I don't doubt that a successor would have been better, but you putting efficient in quotes seems to indicate that you aren't arguing against the fundamental increase in cost per passenger mile when a plane goes at Mach 1.05 compared to Mach 0.95. Fundamental? No. Substantial, yes. Well, we may be arguing semantic again. Ive seen fundamental costs being about a factor of 5 or so per passenger. I guess that would allow for That's not political. The decision to use tax money to subsidize the travel of the richest businessmen is, of course, political. The politics came in when a swathe of countries banned the Concorde from overflying. That's what killed it. Didn't take long before the only route for Concorde was the transatlantic shuttle, and even then, only the very rich could afford it. After looking into this, there is some truth in this. But, you do know it was environmental politics, right? Thats what killed the US SST program http://en.wikipedia.org/wiki/Boeing_2707 I know how loud sonic booms sounded when I was a kid. I can see how easy it was to get people opposed to them happening all the time. That's a scale issue. When only a handful are ever built, the RD isn't every going to be repaid. Thats OK, and I understand it. But, at the same time, I recall the tremendous pride of Britain and France on stealing a march on the US at the time. You seem to think the subsidies were aimed towards Concorde's final fate. They weren't, they were aimed at getting the time of long-haul flights down. Even today, it takes a day to get from London to Sydney. Concorde was supposed to halve that. But, supersonic flight is a fuel hog. Look at the range of the 747 vs. the Concord and their fuel loads per passenger. One would have to stop for fueling several times to make that distance. I realize that most planes have to stop once, including the 747, but the 777 can make it in one. The Concord would still be faster, and the point is moot due to environmental concerns that wont go away. But, I think without those, it is reasonable to assume that some businessmen would be willing to pay 5x the fare for a thin seat to save half of the time. But, granting that, my point is that natural barriers do exist. Some lines of inquiry and technology are easier than others. Right now, computer chips remain under Moores law and it appears that gene manipulation is doing even better. Let me try an analogy to illustrate my point. We scientists and RD engineers are like 16th century explorers. Part of where they went was determined by their will, our abilities, their technology, etc. But, part of it was determined by the lay of the land. The Northwest passage didnt exist until last year (the Northeast passage existed for a few years before that). There was no easy way around the Americas. Valley that were explored seemed promising as passages over the Continental divide, but few good ones exist. My argument is that we shouldnt think of green energy as merely a test of our will. It is also dependant on the lay of the land. Past behavior doesnt guarantee future behavior, but its much more likely that, in 10 years, we will have a 1 terabyte drive for $100 than have a plane that can carry 1500 passengers that flies for the same price (not price per passenger but total price) as a plane that carries 100. t's chicken wire on poles, Dan. Strung over land that can still be used for other stuff. The rectennas are by far the smallest costs in the whole thing... Im not sure its quite that simple. I agree it will probably be a lot cheaper than the transmitter. But, I don't think the process is trivial. If the transmission is that simple, why wouldnt we be using it for remote locations now. Just put a tower up and transmit the energy? I understand that, but there was a huge inertia ...? I understand that, but there was a huge inertia with mainframe computers in the 70s and they soon became dinosaurs. Yet, the capital invested in the Z-density I helped design was small, yet it was 20 years before it was worth the bother to design a new
Re: An interesting response
On 03/05/2008, at 1:48 PM, [EMAIL PROTECTED] wrote: You seem to think the subsidies were aimed towards Concorde's final fate. They weren't, they were aimed at getting the time of long-haul flights down. Even today, it takes a day to get from London to Sydney. Concorde was supposed to halve that. But, supersonic flight is a fuel hog. Look at the range of the 747 vs. the Concord Concorde. With an e. and their fuel loads per passenger. One would have to stop for fueling several times to make that distance. I realize that most planes have to stop once, including the 747, but the 777 can make it in one. London to Sydney? In one hop? No current commercial aircraft can do it. London to Sydney is almost 13.500 miles and the 777 has a range of a bit over 9000. I'll come back to the rest of the post later. Charlie. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: An interesting response
Reality check. Coal power is about 0.04 cents / kWh I'm in the solar biz. The reality is: Orbital stations are operational for 100% of the time. Earthbound stations are operational at most 50% of the time (because of the day/night cycle). But orbital stations cost a LOT more to get going. This eliminates any advantage you might get from the 50% power gain, and then some. I'm a proponent of earthbound CPV systems, and am actively seeking investment in my particular design. I know this industry inside and out, and can tell you straight out that orbital power gen systems will simply not fly, for cost-effectiveness reasons. Regards, Curtis. With very expensive receivers you can get about 40% efficiency. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Charlie Bell Sent: Friday, April 18, 2008 1:40 PM To: Killer Bs (David Brin et al) Discussion Subject: Re: An interesting response On 18/04/2008, at 7:16 AM, hkhenson wrote: At 12:00 PM 4/17/2008, Dan M wrote: Nothing works 100% of the time, but lets assume a 95% efficiency, or running 8322 hours/year. The cost is, then, about $39 per kWh. If you do it this way, the cost the next year is zero. That's not good accounting. These things should run for decades. If you wrote it off in 10 years, it would be $3.90 a kWh. Ah yes. I totally missed that part of Dan's calculation, despite the fact I used precisely the correct calculation in my own roof-top solar calculation - I blame my flu. Fucking schoolboy error. So - assuming a yearly running cost at 10% of start-up, that's still about 5 bucks a kwh. So comparable to rooftop solar, but with massively more startup cost. Hmmm. So why's it better? C. ___ http://www.mccmedia.com/mailman/listinfo/brin-l ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
On 25/04/2008, at 4:19 AM, Curtis Burisch wrote: Reality check. I'm a proponent of earthbound CPV systems, and am actively seeking investment in my particular design. I know this industry inside and out, and can tell you straight out that orbital power gen systems will simply not fly, for cost-effectiveness reasons. Well, there we have it. Is there nothing that someone on here isn't an expert in? Charlie. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
On Fri, 25 Apr 2008, Charlie Bell wrote: On 25/04/2008, at 4:19 AM, Curtis Burisch wrote: Reality check. I'm a proponent of earthbound CPV systems, and am actively seeking investment in my particular design. I know this industry inside and out, and can tell you straight out that orbital power gen systems will simply not fly, for cost-effectiveness reasons. Well, there we have it. Is there nothing that someone on here isn't an expert in? And if anyone was thinking of saying child car seats, try again. :) Julia ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: An interesting response
Coal power is about 0.04 cents / kWh Whoops. That was supposed to be 4 cents / kWh. I also neglected to mention the following stats that may be of interest: Power in earth orbit: 1300 W/m^2 Power at earth surface: 1000 W/m^2 Regards, Curtis. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
On 18/04/2008, at 7:16 AM, hkhenson wrote: At 12:00 PM 4/17/2008, Dan M wrote: Nothing works 100% of the time, but lets assume a 95% efficiency, or running 8322 hours/year. The cost is, then, about $39 per kWh. If you do it this way, the cost the next year is zero. That's not good accounting. These things should run for decades. If you wrote it off in 10 years, it would be $3.90 a kWh. Ah yes. I totally missed that part of Dan's calculation, despite the fact I used precisely the correct calculation in my own roof-top solar calculation - I blame my flu. Fucking schoolboy error. So - assuming a yearly running cost at 10% of start-up, that's still about 5 bucks a kwh. So comparable to rooftop solar, but with massively more startup cost. Hmmm. So why's it better? C. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: An interesting response
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of hkhenson Sent: Wednesday, April 16, 2008 8:10 PM To: brin-l@mccmedia.com Subject: An interesting response At 12:00 PM 4/16/2008, Dan M wrote: (Keith wrote) At 12:00 PM 4/11/2008, Dan M wrote: (Keith wrote) Takes 10 200 ton payload rockets each flying once a day to do it and with a blank check perhaps under 5 years to work up to this production rate and 6-7 years from start to get to a $50 billion a year revenue stream increasing at $25 billion a year. OK, let's do the math on that. At the present time, the cost of lift to geosynchronous orbit is $20,000 per kg or $20M per metric ton. Ten 200 ton payloads would be about 40 billion per day or 14.6 trillion per year. That's roughly the GDP of the US. And the analogy would be how impossible it is to build a dam sending all the contents in Fed Ex envelopes. The trick is, as it always has been, to lower launch costs. Unfortunately, even in inflation adjusted dollars, launch costs haven't dropped much over the past 40 years. I agree with you. The question is why? I wrote a blog on that general topic at the Scientific American website http://science-community.sciam.com/blog-entry/Dan-Ms-Blog/Unfortunate- Promin ent-Misconception-Concerning-Tech/34870 It was an interesting blog, though *social problems* are in a very different class than engineering ones like going to the moon. At least they are now. Ask and I will point you to a dark story about how they might be solved. The essence is that when the engineering community starts working on something, it starts working on the obviously solvable problems first. Then, progress slows as the easy problems are solved and harder problems are faced. The point at which this happens, and the manner in which it happens is based on what is found. The speed of sound barrier is rather significant, and we have not found a way to develop efficient planes that go at Mach 1.1 almost 60 years after we first went above Mach 1. It's not the cost of energy. No, it's the cost of the system. A nearly hundred percent efficient space elevator lifts about 2400 mt a day (on less than a GW) snip I've invented a few things that are used worldwide and am still engaged in practical science/engineering. I've worked close to guys who's inventions have reduce world costs for producing oil by about 250 million/day. Since there are around 80 million barrels a day produced, that's a reduction of about 3%. So, I think I'm fairly familiar with processes that are economical and that work. I have not seen anything in what you have written on this subject that gives an indication of an understanding of the nature of practical solutions to problems. What do you want? The current 747 cost about $300 million and dry masses out to about 185 mt or $1.6 million a ton. Produced in similar tonnage, do you see any reason these rockets would cost more than per ton than a 747? If so, why? For the rocket itself, not counting all the other expenses associated with launches, that's not an unreasonable cost. First and second stage mass 619 tons, (third stage is mostly power sat parts) so if they cost on a par with a 747, they would cost just a hair over a billion each, with one coming off the production line every 20 days, or about 31 mt a day. That might sound like a lot, but I have worked in a locomotive factory that made 30 times that much a day in product (8-9 locomotives a day at 113 mt each). At peak production 747s were coming off the line at a slightly higher tonnage per year. If you use them for 200 flights the capital cost per flight is $5 million /200,000kg or $25/kg. Here's where you throw in the unspecified assumption. A simple disposable rocket, like the ones being used by all launch facilities but the shuttle, could cost about what you said. But, then you talk about reusable rockets and assume that the initial capital cost is the critical factor. The fantasy of the space shuttle was that it could be reused easily. 10 years into the mission, it was supposed to require a very small ground crew, getting lift costs to near earth orbit down to about $25/kg or some such number. But, the maintenance is very high and expensive. The shuttle costs a lot of money to fly, even though we are not buying new shuttles, the big fuel tank is the cheapest part of the assembly, and the solid fuel rockets are recoverable. So, I've seen no estimates for this, just the same arm waving I heard about the shuttle years ago. I can think of Russia, Japan, the EU, the US, and China all having significant lift capacity, and Russia is the cheapest available one I know of. I tend to look at actual costs and their trends as a guideline, not estimates that make unproven assumptions. I realize
Re: An interesting response
At 12:00 PM 4/17/2008, Dan M wrote: Nothing works 100% of the time, but lets assume a 95% efficiency, or running 8322 hours/year. The cost is, then, about $39 per kWh. If you do it this way, the cost the next year is zero. That's not good accounting. These things should run for decades. If you wrote it off in 10 years, it would be $3.90 a kWh. And what kind of a deal would the Russians give you if you wanted to launch 110 of these a day? Keith ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
hkhenson said the following on 4/17/2008 5:16 PM: At 12:00 PM 4/17/2008, Dan M wrote: And what kind of a deal would the Russians give you if you wanted to launch 110 of these a day? Perhaps this is naive of me, but who is going to want to build the multiple launching facilities 110 launches/day will require? I would expect most of those pads would go idle once the project completed, no? Seems like a sunk cost to me. --[Lance] -- GPG Fingerprint: 409B A409 A38D 92BF 15D9 6EEE 9A82 F2AC 69AC 07B9 CACert.org Assurer ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: An interesting response
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of hkhenson Sent: Friday, April 11, 2008 3:43 PM To: brin-l@mccmedia.com Subject: RE: An interesting response At 12:00 PM 4/11/2008, Dan M wrote: (Keith wrote) Takes 10 200 ton payload rockets each flying once a day to do it and with a blank check perhaps under 5 years to work up to this production rate and 6-7 years from start to get to a $50 billion a year revenue stream increasing at $25 billion a year. OK, let's do the math on that. At the present time, the cost of lift to geosynchronous orbit is $20,000 per kg or $20M per metric ton. Ten 200 ton payloads would be about 40 billion per day or 14.6 trillion per year. That's roughly the GDP of the US. And the analogy would be how impossible it is to build a dam sending all the contents in Fed Ex envelopes. The trick is, as it always has been, to lower launch costs. Unfortunately, even in inflation adjusted dollars, launch costs haven't dropped much over the past 40 years. I agree with you. The question is why? I wrote a blog on that general topic at the Scientific American website http://science-community.sciam.com/blog-entry/Dan-Ms-Blog/Unfortunate-Promin ent-Misconception-Concerning-Tech/34870 The essence is that when the engineering community starts working on something, it starts working on the obviously solvable problems first. Then, progress slows as the easy problems are solved and harder problems are faced. The point at which this happens, and the manner in which it happens is based on what is found. The speed of sound barrier is rather significant, and we have not found a way to develop efficient planes that go at Mach 1.1 almost 60 years after we first went above Mach 1. It's not the cost of energy. No, it's the cost of the system. A nearly hundred percent efficient space elevator lifts about 2400 mt a day Of course you have the cost of the elevator and cleaning up the space junk as capital costs. It can't be done at all now because we don't have the cable, but just for analysis put a $1000 billion price tag on it. Sure, if the cost were that low, it would work. But setting a figure like that reminds me of the story of the engineer, the chemist, and the accountant who were all stuck on a desert island with cans of food and no can opener.I'm sure you've all heard the jokebut the punchline is the accountant, after hearing suggestions from the engineer and the chemist that don't work gives his solution that starts with first assume we have a can opener. I've invented a few things that are used worldwide and am still engaged in practical science/engineering. I've worked close to guys who's inventions have reduce world costs for producing oil by about 250 million/day. So, I think I'm fairly familiar with processes that are economical and that work. I have not seen anything in what you have written on this subject that gives an indication of an understanding of the nature of practical solutions to problems. Done with rockets of this sort http://www.ilr.tu-berlin.de/koelle/Neptun/NEP2015.pdf the energy input is about 15 times that high, or from $15 /kg down to $1.50 as you get less and less expensive energy. I went to this website, and it looked like a speculative conference. Vaporware is easy to build. Doing something that works is hard. Most things we wish we could do we do not know how to do. I think that this is the absolutely fundamental difference you have with folks who argue for nuclear reactors vs. space based solar power. We've demonstrated safety mechanisms, Can you be specific about what you mean here? Sure, to be effective, power would have to be transmitted down in a fairly dense fashion. One needs mechanisms that provide feedback to turn the power off should the aim stray. Plus, it costs money to build the actual arrays. That's true, but with just mild concentration you can get at least 10 times more power out of a solar cell in space. We have an overwhelmingly fundamental difference here. I have looked at the solar arrays for the space station and they are expensive. If concentration were trivial in space, don't you think they would have used it? We know on earth that techniques that use concentration have practical problems that have prevented them from being cost effective. If you can find a way to drop launch costs a factor of 100 to 500, then space based solar becomes a player. There is nothing like that on the horizon. There doesn't seem to be any reason a really huge throughput transport system should not be able to give you that much reduction. Then, why hasn't it happened with the scores of airline industries? 747s were brought online in the '60salmost 40 years ago. 747s remain competitive. The airline industry is huge, and we've only seen incremental improvements over the past 40 years
Re: An interesting response
On 17/04/2008, at 3:14 AM, Dan M wrote: The speed of sound barrier is rather significant, and we have not found a way to develop efficient planes that go at Mach 1.1 almost 60 years after we first went above Mach 1. So-called supercruise. The biggest problem with going over Mach 1 is political and legal, not technological - had Concorde not been killed by politics, its successor would have been an efficient supersonic plane. It's not the cost of energy. No, it's the cost of the system. Yep. Can you be specific about what you mean here? Sure, to be effective, power would have to be transmitted down in a fairly dense fashion. One needs mechanisms that provide feedback to turn the power off should the aim stray. Current designs seem to show a wide collection with a diffuse beam, so that it's relatively safe to be under the beam. There doesn't seem to be any reason a really huge throughput transport system should not be able to give you that much reduction. Then, why hasn't it happened with the scores of airline industries? 747s were brought online in the '60salmost 40 years ago. 747s remain competitive. The airline industry is huge, and we've only seen incremental improvements over the past 40 years. And 747s, beyond the basic airframe and control systems, are very different to what they were in the 70s. (by the way, they were brought online in 1970 - maiden flight was '69, but it wasn't delivered 'til the following year). There isn't a need for that many huge airliners, only around 1400 747s have been built, and it's taken 'til last year for the 747s size and efficiency to be surpassed by the A380 (which is an incredible plane) - improvements in the mid-size airliners have been marked, however, mainly because there's a lot more competition. Point on this part is that there is huge inertia when there's huge capital expenditure - if you've spent a few tens of millions on a plane in 1970 or 1980 you're going to keep using it as long as you can, 'cause a similar plane costs a few hundred million in 2008. All that said, I'd like to see you, Dan, try to put together a cost- analysis on a powersat project. You're very good at using your tenacious posting to naysay, so I'd like to see you attempt to solve the problem so I can see where the problems are. C. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: An interesting response
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Charlie Bell Sent: Wednesday, April 16, 2008 6:49 PM To: Killer Bs (David Brin et al) Discussion Subject: Re: An interesting response On 17/04/2008, at 3:14 AM, Dan M wrote: The speed of sound barrier is rather significant, and we have not found a way to develop efficient planes that go at Mach 1.1 almost 60 years after we first went above Mach 1. So-called supercruise. The biggest problem with going over Mach 1 is political and legal, not technological - had Concorde not been killed by politics. Well, Concord was a political animal from the very beginning wasn't it? It was a tax subsidized showcase for Britain and France from the start. IIRC, it never really was a profit center. its successor would have been an efficient supersonic plane. I don't doubt that a successor would have been better, but you putting efficient in quotes seems to indicate that you aren't arguing against the fundamental increase in cost per passenger mile when a plane goes at Mach 1.05 compared to Mach 0.95. That's not political. The decision to use tax money to subsidize the travel of the richest businessmen is, of course, political. Can you be specific about what you mean here? Sure, to be effective, power would have to be transmitted down in a fairly dense fashion. One needs mechanisms that provide feedback to turn the power off should the aim stray. Current designs seem to show a wide collection with a diffuse beam, so that it's relatively safe to be under the beam. OK, then there would be the cost of a wider array, earlier designs had cheaper local receivers with feedback required to keep the beam on. I'm not saying that this would be a showstopper, it's just that it's part of the price that has to be figured in. http://en.wikipedia.org/wiki/Boeing_747 And 747s, beyond the basic airframe and control systems, are very different to what they were in the 70s. (by the way, they were brought online in 1970.. OK, the first commercial flight was Jan, 22, 1970...my apologies for rounding. But, the 747 is still in competition, sometimes on the same routes as smaller planes...and there are still a number on order (see site given above). Point on this part is that there is huge inertia when there's huge capital expenditure - if you've spent a few tens of millions on a plane in 1970 or 1980 you're going to keep using it as long as you can, 'cause a similar plane costs a few hundred million in 2008. I understand that, but there was a huge inertia All that said, I'd like to see you, Dan, try to put together a cost- analysis on a powersat project. Sure, be glad to. The cheapest commercially available launch to geosynchronous orbit (GEO) that I know of is the Russian Zenit program. For about 90 million, one can get a payload of just over 1800 kg into GEO. That's just under 50,000 per kg. http://en.wikipedia.org/wiki/Zenit_rocket OK, so lets calculate output per kg. of weight. From a site that is promoting their solar cells for use in orbit http://www.mdatechnology.net/techprofile.aspx?id=226 we get an output of 150W/kg. That gives us a launch cost of about $325 per watt (I'm rounding down now instead of up). Nothing works 100% of the time, but lets assume a 95% efficiency, or running 8322 hours/year. The cost is, then, about $39 per kWh. Dan M. tenacious posting to naysay, so I'd like to see you attempt to solve the problem so I can see where the problems are. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
On 17/04/2008, at 12:26 PM, Dan M wrote: So-called supercruise. The biggest problem with going over Mach 1 is political and legal, not technological - had Concorde not been killed by politics. Well, Concord was a political animal from the very beginning wasn't it? It was a tax subsidized showcase for Britain and France from the start. IIRC, it never really was a profit center. All aircraft mfrs are subsidised. Yes, it was supposed to be a technology its successor would have been an efficient supersonic plane. I don't doubt that a successor would have been better, but you putting efficient in quotes seems to indicate that you aren't arguing against the fundamental increase in cost per passenger mile when a plane goes at Mach 1.05 compared to Mach 0.95. Fundamental? No. Substantial, yes. That's not political. The decision to use tax money to subsidize the travel of the richest businessmen is, of course, political. The politics came in when a swathe of countries banned the Concorde from overflying. That's what killed it. Didn't take long before the only route for Concorde was the transatlantic shuttle, and even then, only the very rich could afford it. That's a scale issue. When only a handful are ever built, the RD isn't every going to be repaid. You seem to think the subsidies were aimed towards Concorde's final fate. They weren't, they were aimed at getting the time of long-haul flights down. Even today, it takes a day to get from London to Sydney. Concorde was supposed to halve that. Can you be specific about what you mean here? Sure, to be effective, power would have to be transmitted down in a fairly dense fashion. One needs mechanisms that provide feedback to turn the power off should the aim stray. Current designs seem to show a wide collection with a diffuse beam, so that it's relatively safe to be under the beam. OK, then there would be the cost of a wider array, It's chicken wire on poles, Dan. Strung over land that can still be used for other stuff. The rectennas are by far the smallest costs in the whole thing... Point on this part is that there is huge inertia when there's huge capital expenditure - if you've spent a few tens of millions on a plane in 1970 or 1980 you're going to keep using it as long as you can, 'cause a similar plane costs a few hundred million in 2008. I understand that, but there was a huge inertia ...? All that said, I'd like to see you, Dan, try to put together a cost- analysis on a powersat project. Nothing works 100% of the time, but lets assume a 95% efficiency, or running 8322 hours/year. The cost is, then, about $39 per kWh. Right. So, how do you improve that. OK, say we can get the launch cost halved by mass producing rockets and stuff. That's still $20/kwh. Coal's a few cents a kwh. Even with carbon sequestration doubling or tripling that, it's still a big gap. Roof-mounted solar, I can get a 1kW system (grid connected) for AUD5200, with 20 year warranty. So say it's doing that 1kw 6 hours a day (paper napkin calculation here), that's 43,800 kw across the life of the system, that's about AUD8/kwh ($7.50/kwh). So still a lot better than a powersat, and that's not factoring in the launch pollution. So... how to bridge the gap? Charlie. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: An interesting response
At 12:00 PM 4/11/2008, Dan M wrote: (Keith wrote) Takes 10 200 ton payload rockets each flying once a day to do it and with a blank check perhaps under 5 years to work up to this production rate and 6-7 years from start to get to a $50 billion a year revenue stream increasing at $25 billion a year. OK, let's do the math on that. At the present time, the cost of lift to geosynchronous orbit is $20,000 per kg or $20M per metric ton. Ten 200 ton payloads would be about 40 billion per day or 14.6 trillion per year. That's roughly the GDP of the US. And the analogy would be how impossible it is to build a dam sending all the contents in Fed Ex envelopes. The trick is, as it always has been, to lower launch costs. Unfortunately, even in inflation adjusted dollars, launch costs haven't dropped much over the past 40 years. I agree with you. The question is why? It's not the cost of energy. A nearly hundred percent efficient space elevator lifts about 2400 mt a day to GEO on an input of about a GW. That's 2.4 million kg/24 million kWh. At ten cents a kWh that's a dollar a kg. At the target sales price of a penny a kWh it's ten cents a kg. Of course you have the cost of the elevator and cleaning up the space junk as capital costs. It can't be done at all now because we don't have the cable, but just for analysis put a $1000 billion price tag on it. Since it is going to be used at least ten years, write it off at $100 billion a year. 2.4 million kg x 365 is close enough to a billion kg. So the capital cost would be around $100 a kg. Done with rockets of this sort http://www.ilr.tu-berlin.de/koelle/Neptun/NEP2015.pdf the energy input is about 15 times that high, or from $15 /kg down to $1.50 as you get less and less expensive energy. The rockets are only assumed to make 200 trips before being junked. At 200 tons payload, they deliver 40,000 mt or 40 million kg. The mass of one of them is about 3 times a 747. If they cost a billion dollars each (produced at 20 a year), $1000 million/ 40 million is $25 a kg. I.e., there is no reason for large volume space travel to cost more than $100 a kg even with rockets. What we need is a transcontinental railroad. What we have in NASA is the Pony Express. Incidentally, the energy returned from a kg of power sat is 4000 kWh. At a penny a kwh that's $40 a year, at ten cents, $400. The income stream (which you estimate at 25 billion/year) Actually it was rising at $25 billion a year from selling power. If you sold the satellites for ten years power production the income stream would be $250 billion a year. would also have to support ground receivers, Rectennas are (from a cost standpoint) installed chicken wire over farmland and inverters (the diodes are almost free). Collecting 1/4 kW from 400 square meters would give you a hundred kW. At pc power supply prices, the inverters are $60 a kW. Counting the chicken wire, poles, diodes and power collecting grid, a 5 GW rectenna would cost $500 million or less and deliver $400 million to $2 billion a year at the bus bars. It would take decades to saturate the market, which for oil alone is about $3 trillion a year. safety mechanisms, Can you be specific about what you mean here? transmission lines, etc. At least for a while you could site the rectennas near existing transmission lines. Plus, it costs money to build the actual arrays. That's true, but with just mild concentration you can get at least 10 times more power out of a solar cell in space. If you can find a way to drop launch costs a factor of 100 to 500, then space based solar becomes a player. There is nothing like that on the horizon. There doesn't seem to be any reason a really huge throughput transport system should not be able to give you that much reduction. However, I don't thing NASA is the right organization to do it. Keith Keith ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
At 12:21 AM Thursday 4/10/2008, hkhenson wrote: I have recently been discussing the scope of a space based power satellite project with a bunch of high powered space engineers. They are all accomplished, one of them was the project engineer for the first moon lander. This started when I scaled a moving cable space elevator large enough (2000 tons a day) to put a real dent in the carbon/energy problems (300 GW/year production rate, displacing all the coal fired plants in the US in one year). So when one of them posted a study of a rocket with about twice the payload of a Saturn V, I extrapolated how many of them and what rate of launches it would take to ferry 2000 tons per day to GEO using rockets instead of a much more questionable space elevator. To my surprise, the energy payback went from under a day for the elevator to 15 days for rockets. You would have to dedicate the first 3 power satellites (15 GW) to making rocket propellants. Hardly a deal breaker. Takes 10 200 ton payload rockets each flying once a day to do it and with a blank check perhaps under 5 years to work up to this production rate and 6-7 years from start to get to a $50 billion a year revenue stream increasing at $25 billion a year. I didn't expect a response other than something like that's interesting but they reacted almost with horror, saying the best they could hope for is an almost useless 1 GW demonstration power sat in the next 10 or 15 years and that the only choice we have is to build lots of nuclear power plants. Now countries and companies in the world for the most part realize that there is a serious problem with energy, and that it isn't going to get better as we slide down the far side of oil production. It seems to me that a project that really could displace all fossil sources of energy with renewable solar energy and (using penny a kWh electricity) reduce the price of synthetic gasoline to a dollar a gallon would get a lot more support than a tiny demonstration project no matter how few in billions it cost. There is no doubt it's a big project, on a par with what we have spent on the Iraq war. But the market for energy is massive, oil alone is $3,000 billion a year. And there is no lack of money to fund it, Exxon can't figure out what to do with their profits so they are buying back $30 billion of their stock a year. The Chinese have a few thousand billions in US notes they would spend on a secure energy source large enough to meet their growing needs. So my question to you, is which be an easier project to sell, a demonstration project for a small number of billions over 10 or 15 years, or a really huge project in the high hundreds of billions to massively displace coal and oil with solar energy from space in under ten years? Keith Henson Or perhaps the real question is which of the following is the case? (1) Your figures and their figures disagree that much, in which case it might be worthwhile to have someone else independently check both sets of figures (probably a good idea in \\any\\ case), or (2) There is more on the agenda than simply finding longer-lasting, less-polluting sources of energy to replace oil. ? Maru . . . ronn! :) ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: An interesting response
Takes 10 200 ton payload rockets each flying once a day to do it and with a blank check perhaps under 5 years to work up to this production rate and 6-7 years from start to get to a $50 billion a year revenue stream increasing at $25 billion a year. OK, let's do the math on that. At the present time, the cost of lift to geosynchronous orbit is $20,000 per kg or $20M per metric ton. Ten 200 ton payloads would be about 40 billion per day or 14.6 trillion per year. That's roughly the GDP of the US. The trick is, as it always has been, to lower launch costs. Unfortunately, even in inflation adjusted dollars, launch costs haven't dropped much over the past 40 years. The income stream (which you estimate at 25 billion/year) would also have to support ground receivers, safety mechanisms, transmission lines, etc. Plus, it costs money to build the actual arrays. If you can find a way to drop launch costs a factor of 100 to 500, then space based solar becomes a player. There is nothing like that on the horizon. Dan M. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: An interesting response
Dan M wrote: The trick is, as it always has been, to lower launch costs. Unfortunately, even in inflation adjusted dollars, launch costs haven't dropped much over the past 40 years. Maybe even if launch costs were _zero_, orbital power satellites could still have a negative energy net production. Last time I heard (when I was working in the Space Industry, and not in the Oil Industry), solar arrays required more energy to be built than the energy they produced during their lifetimes. Alberto 'oil rulez, fsck space!' Monteiro ___ http://www.mccmedia.com/mailman/listinfo/brin-l
