Re: For David Brin and the rest of you
From: Pat Mathews > How much does it cost in energy as well as in dollars? Substantial. I figured this for an elevator and got that the elevator had a 3 day payback for the parts and the same for lifting. The calculated energy investment for a kW of capacity was paid back in 53 days. Figured at 24 kWh/day, 1272 kWh. 94% of that is in the hydrogen used mostly for reaction mass. The startup scale project, 100 GW of new power plant per year takes a few LNG tankers a week to make the hydrogen > Cradle to grave? Mass in GEO is useful, so a worn out power sat would probably be fed into making new ones. > And is the initial investment within the capability of the United States > right now? (I know. $60B is peanuts. Even so -) or any corporation? There are several current energy projects, most of them LNG, that are in that range. Apple has $100 billion. If Steve Jobs were alive they might use it for this project, but without him, probably not. The most likely to do it are the Chinese, who certainly need the energy and a way to quit burning coal. How seriously to take this, I don't know. http://articles.timesofindia.indiatimes.com/2012-11-02/india/34877401_1_space-solar-power-space-collaboration-v-ponraj > What are the economics - in the terms mentioned above - of beaming solar > power down to earth? (Those of using it space are, of course, well > understood by now.) Space based solar power will under cut coal by half or it is not worth doing. > Over the past 7 decades, I've come to see the wisdom of getting a good, solid > cost accounting done before instituting any large scale project. If you want to go through the spreadsheet analyzing the project as a business, ask for it. > Anyway, subject to that sort of analysis, it does sound good indeed. Now all it needs is people. From: ALBERTO VIEIRA FERREIRA MONTEIRO > Even if these things were economically viable (which they probably ain't), ambientally it would be a disaster. I can't image the Earth getting such extra amount of radiant energy and not turning it (she? Gaia?) into a hell much worse than the most pessimistic images of the most radical ecogroups. They were not economically viable before April. Now they might be. But let's put numbers on your concerns. G. Harry Stine put a maximum capacity for power sats in GEO at 177 TW. I don't know exactly how he did it, I get similar but smaller numbers around 120 TW. Because the energy is higher grade than heat, 12 TW would probably be enough to replace fossil fuel use.. The Earth receives 174 petawatts of incoming solar radiation of which 70% is absorbed by clouds, oceans and land masses, about 122 PW. So the amount of energy added to the earth by 12 TW of power satellites is around 1 part in ten thousand. But wait, there is more. If you have this kind of industrial base in space, sunshades in L! are fully possible. How cold do you want? Alberto Monteiro (oil company guy) As an oil company guy, you might start thinking about what can be done with oceans of cheap power. There are things that hydrocarbons can do that just can't be electrified at reasonable cost. If you go through the chemistry and energy economics, synthetic carbon neutral gasoline can be made for about a dollar a gallon if the cost of power gets down into the 1-2 cent range. I know ExxonMobile is thinking about it. From: Pat Mathews >And of course, anything that can be that easily weaponized, will be. Remember >Heinlein's Loonies winning their independence by throwing rocks at the mother >world? It's really hard to weaponize the microwave transmission link. Microwave optics just will not let you focus it tight enough to be particularly dangerous. The propulsion lasers to get the parts up to GEO at a cost where the whole thing makes economic sense, those are weapons, game changing weapons. And if I had to bet, it would be for them to be controlled by the Chinese. Keith Henson ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
RE: For David Brin and the rest of you
>It looks like a combination of Skylon, a project being developed in the UK and big propulsion lasers will get the >cost to under $100/kg to GEO. Do you have any vidios of lasers holding up, say, a 10kg object, for 20 minutes and keeping it under control. This would be one of the easy feasability tests one would do at the start of any serious undertaking. That would be one of many things that would have to be sucessfully tested before the project would be deemed even possible. Dan M. ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
Re: For David Brin and the rest of you
On 9/5/2013 4:54 PM, Keith Henson wrote: The propulsion lasers to get the parts up to GEO at a cost where the whole thing makes economic sense, those are weapons, game changing weapons. And if I had to bet, it would be for them to be controlled by the Chinese. Keith Henson _ Now that's a problem with the plan. If the lasers could be weapons controlled by one country, I can see other countries upset enough to sabotage the whole project. There'd need to be a political solution that made it clear the lasers weren't going to be used as weapons by any group short of most of the UN Security Council. ---David Zeus' lightning bolt, Maru ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
Re: For David Brin and the rest of you
In a message dated 9/5/2013 4:24:09 A.M. US Mountain Standard Time, albm...@centroin.com.br writes: where the Mad Scientist tries to destroy the Earth by placing an enormous mirror or lens in orbit, concentrating solar energy? It's not in orbit; it's in London melting parked cars. Google: London building melting cars. ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
Re: For David Brin and the rest of you
On 9/5/2013 7:24 AM, ALBERTO VIEIRA FERREIRA MONTEIRO wrote: David Hobby wrote: Or are you worried about energy being beamed down inefficiently, producing much more heat than just the amount from people using energy directly? No, even if it was possible to beam energy with 100% efficiency... it's still energy. It comes down, it must get out. If not, Earth gets cooked. Alberto-- Sorry, I don't understand how getting energy from space is inherently worse than getting energy by burning stuff that's been sitting in the ground for millions of years. Either way, it's "extra" energy. Plus, burning carbon compounds from the ground adds to the greenhouse effect, which just beaming power down would not. There may be good arguments for conserving more rather than having cheap clean power from space, but yours isn't one. ---David ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
RE: For David Brin and the rest of you
> Date: Thu, 5 Sep 2013 08:24:00 -0300 > Subject: Re: For David Brin and the rest of you > From: albm...@centroin.com.br > To: brin-l@mccmedia.com > > David Hobby wrote: > > > > Or are you worried about energy being beamed down inefficiently, producing > > much more heat than just the amount from people using energy directly? > > > No, even if it was possible to beam energy with 100% efficiency... > it's still energy. It comes down, it must get out. If not, Earth gets > cooked. > > Hell on Earth, the nightmare of science fiction, brought to us by > those that try to save the planet. Isn't this the scenario of some > cheap sci-fi, where the Mad Scientist tries to destroy the Earth by > placing an enormous mirror or lens in orbit, concentrating solar > energy? > > Just we don't need mirror or lens, place a lot of death ray > satellites. Sorry, power satellites. > > Alberto Monteiro > And of course, anything that can be that easily weaponized, will be. Remember Heinlein's Loonies winning their independence by throwing rocks at the mother world? ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
Re: For David Brin and the rest of you
David Hobby wrote: > > Or are you worried about energy being beamed down inefficiently, producing > much more heat than just the amount from people using energy directly? > No, even if it was possible to beam energy with 100% efficiency... it's still energy. It comes down, it must get out. If not, Earth gets cooked. Hell on Earth, the nightmare of science fiction, brought to us by those that try to save the planet. Isn't this the scenario of some cheap sci-fi, where the Mad Scientist tries to destroy the Earth by placing an enormous mirror or lens in orbit, concentrating solar energy? Just we don't need mirror or lens, place a lot of death ray satellites. Sorry, power satellites. Alberto Monteiro ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
