Comments on: Financial and Organizational Analysis for a Space Solar Power System http://blog.nss.org/?p=1113 Blogging for the creation of a spacefaring civilization Sun, 19 May 2013 23:09:20 +0000 http://wordpress.org/?v=2.7 hourly 1 By: Royce http://blog.nss.org/?p=1113&cpage=1#comment-11798 Royce Mon, 25 Apr 2011 16:18:25 +0000 http://blog.nss.org/?p=1113#comment-11798 You can achieve 100% power in LEO, so the idea that only GEO will work is not correct. To get 100% power in LEO you put the SBSP satellite in a Sun-synchronous, Dusk to Dawn orbit. Here the satelite will ride the devide between day and night and the solar panels will always face the sun. The canadian satellites Radarsat 1 and 2 use this orbit. To further solve the problem requires that you place reflector satellites in an equatorial 2,000km orbit. So the power produced by the SBSP satellite is not sent directly to the ground, instead it is beamed to the reflector satellite and then to the ground. Doing this allows you to get the same benefits as GEO without the in-space transporatation cost or massive space infrastructure. You can achieve 100% power in LEO, so the idea that only GEO will work is not correct. To get 100% power in LEO you put the SBSP satellite in a Sun-synchronous, Dusk to Dawn orbit. Here the satelite will ride the devide between day and night and the solar panels will always face the sun. The canadian satellites Radarsat 1 and 2 use this orbit. To further solve the problem requires that you place reflector satellites in an equatorial 2,000km orbit. So the power produced by the SBSP satellite is not sent directly to the ground, instead it is beamed to the reflector satellite and then to the ground. Doing this allows you to get the same benefits as GEO without the in-space transporatation cost or massive space infrastructure.

]]> By: David Workman http://blog.nss.org/?p=1113&cpage=1#comment-1646 David Workman Tue, 21 Jul 2009 21:05:13 +0000 http://blog.nss.org/?p=1113#comment-1646 Yes, you would still get some dark time with "low earth orbit" but very little with "geosynchronous orbit". Remember that the Earth is about 24,000 miles circumference, which is very close to the GEO orbit distance - so if you take a globe and wrap a piece of string around the equator, and then stretch that piece of string out FROM the equator, it's easy to see that the axis tilt of the earth will keep the end of the string in daylight 24 hours a day (except for just a few hours during the equinox, which happens twice a year). Yes, you would still get some dark time with “low earth orbit” but very little with “geosynchronous orbit”. Remember that the Earth is about 24,000 miles circumference, which is very close to the GEO orbit distance - so if you take a globe and wrap a piece of string around the equator, and then stretch that piece of string out FROM the equator, it’s easy to see that the axis tilt of the earth will keep the end of the string in daylight 24 hours a day (except for just a few hours during the equinox, which happens twice a year).

]]> By: Raul Gutierrez http://blog.nss.org/?p=1113&cpage=1#comment-1632 Raul Gutierrez Mon, 20 Jul 2009 20:20:49 +0000 http://blog.nss.org/?p=1113#comment-1632 In the early stages of our research we clearly understood that we didn't have neither the time nor the technical knowledge to perform an in-depth study from that perspective. Besides, it was evident that a lot of research have been done with better means than those available to us. Instead we questioned ourselves, "aside from the evident reasons (expensive R&D and launch, as well as lack of appropiate infrastructure for setting up in space such a system) why SSPS hasn't become a reality?." So we studied and proposed some financial and organizational strategies that could help solving part of the actual and foreseable problems of bringing SSPS to life. We are proud that our work has found some acceptance. At the same time we ask for feedback both in the technical ground as well as from the "business" point of view. This way we can better reach our goal of contributing to solve the stated question. In the early stages of our research we clearly understood that we didn’t have neither the time nor the technical knowledge to perform an in-depth study from that perspective. Besides, it was evident that a lot of research have been done with better means than those available to us. Instead we questioned ourselves, “aside from the evident reasons (expensive R&D and launch, as well as lack of appropiate infrastructure for setting up in space such a system) why SSPS hasn’t become a reality?.” So we studied and proposed some financial and organizational strategies that could help solving part of the actual and foreseable problems of bringing SSPS to life. We are proud that our work has found some acceptance. At the same time we ask for feedback both in the technical ground as well as from the “business” point of view. This way we can better reach our goal of contributing to solve the stated question.

]]> By: Ray Van De Walker http://blog.nss.org/?p=1113&cpage=1#comment-1614 Ray Van De Walker Mon, 20 Jul 2009 05:10:33 +0000 http://blog.nss.org/?p=1113#comment-1614 Insolation is 1435W/M^2 in orbit, and as little as 1100 on the ground in an equatorial desert. It's less elsewhere. The capacity factor from weather, night, sun angle, etc. is about 20%. In geosynchronous orbit the capacity factor is better than 99%. Eclipses are still a problem in low earth orbit. Insolation is 1435W/M^2 in orbit, and as little as 1100 on the ground in an equatorial desert. It’s less elsewhere. The capacity factor from weather, night, sun angle, etc. is about 20%. In geosynchronous orbit the capacity factor is better than 99%. Eclipses are still a problem in low earth orbit.

]]> By: Karen Shea http://blog.nss.org/?p=1113&cpage=1#comment-1603 Karen Shea Sun, 19 Jul 2009 16:03:10 +0000 http://blog.nss.org/?p=1113#comment-1603 The factor of 7 is derived from 4 factors I believe. 1. a factor of 2 from the diurnal cycle(Day and Night). In GEO solar cells are nearly always in sunlight. 2. Sun angle. On earth Solar cells are fixed and sun angle is not always optimum. In space solar cells will always be at the optimum angle. 3. Weather 4. Atmosphere The factor of 7 is derived from 4 factors I believe.

1. a factor of 2 from the diurnal cycle(Day and Night). In GEO solar cells are nearly always in sunlight.

2. Sun angle. On earth Solar cells are fixed and sun angle is not always optimum. In space solar cells will always be at the optimum angle.

3. Weather

4. Atmosphere

]]> By: james walmsley http://blog.nss.org/?p=1113&cpage=1#comment-1599 james walmsley Sun, 19 Jul 2009 13:58:59 +0000 http://blog.nss.org/?p=1113#comment-1599 Hi Karen, I've answered my own question concerning the factor of seven you mentioned. It seems as though this would refer to the lower terrestrial figure during winter rather than the best case scenario of summer mid day. Hi Karen,

I’ve answered my own question concerning the factor of seven you mentioned. It seems as though this would refer to the lower terrestrial figure during winter rather than the best case scenario of summer mid day.

]]> By: James Walmsley http://blog.nss.org/?p=1113&cpage=1#comment-1597 James Walmsley Sun, 19 Jul 2009 13:34:15 +0000 http://blog.nss.org/?p=1113#comment-1597 Hi Karen, You've made some good points on cost reductions in relation to increased launches. Concerning the other topic, In my reading so far I have not founnd the factor of seven that you mentioned in terms of space based solar output over ground based ouput. The best I have read about so far was a factor of two but that was only refering to the amount of energy striking the panels. If you could tell me where I could read up on the remaining increase in effeciency then I would like to do so. Jim Hi Karen,

You’ve made some good points on cost reductions in relation to increased launches.

Concerning the other topic, In my reading so far I have not founnd the factor of seven that you mentioned in terms of space based solar output over ground based ouput. The best I have read about so far was a factor of two but that was only refering to the amount of energy striking the panels. If you could tell me where I could read up on the remaining increase in effeciency then I would like to do so.

Jim

]]> By: Karen Shea http://blog.nss.org/?p=1113&cpage=1#comment-1594 Karen Shea Sun, 19 Jul 2009 12:17:11 +0000 http://blog.nss.org/?p=1113#comment-1594 Yes, solar cells in space can produce 7 times more energy as those on the ground and deliver energy to when ever it is needed. Also the trap we are in with launch costs is they are high because launch rates are low so launch facilitites can't use mass production techniques. If space solar power becomes a reality launch costs will drop because the number of launches will go up dramtically. Yes, solar cells in space can produce 7 times more energy as those on the ground and deliver energy to when ever it is needed.

Also the trap we are in with launch costs is they are high because launch rates are low so launch facilitites can’t use mass production techniques. If space solar power becomes a reality launch costs will drop because the number of launches will go up dramtically.

]]> By: Mark Dansie http://blog.nss.org/?p=1113&cpage=1#comment-1578 Mark Dansie Sat, 18 Jul 2009 22:35:42 +0000 http://blog.nss.org/?p=1113#comment-1578 what a lot of hog wash. Can anyone actually believe the costs can be recovered by sending 3 tonne payloads into space. Madness what a lot of hog wash. Can anyone actually believe the costs can be recovered by sending 3 tonne payloads into space.
Madness

]]> By: Michael Martin-Smith http://blog.nss.org/?p=1113&cpage=1#comment-1569 Michael Martin-Smith Sat, 18 Jul 2009 13:58:21 +0000 http://blog.nss.org/?p=1113#comment-1569 This should mean that a demo SSPS, as is proposed, in the not too distant future could actually give a useful yield of solar photovoltaic energy, and make the case more convincingly for fullscale development. This should mean that a demo SSPS, as is proposed, in the not too distant future could actually give a useful yield of solar photovoltaic energy, and make the case more convincingly for fullscale development.

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