Boondoggle or future of energy? Space Based Solar Power TED talk

[SamAdams]

Good 20 minute talk on Space Based Solar Power by the second private firm (Space Energy Inc.) to appear in the press the last few months (in addition to Solaren who announced a power purchase agreement with PG&E). Crazy enough to work?

[ThePythonicCow]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

See Space based solar power (wikipedia) for further details. These things would be friggin huge. Something like 50 or 80 tons and a kilometer across per each geosynchronous satellite, with 10 kilometer antenna's on the ground to receive the focused beam.

Getting that much stuff in to a geosynchronous orbit and constructing such large structures there will be a challenge.

[ASH]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

See Space based solar power (wikipedia) for further details. These things would be friggin huge. Something like 50 or 80 tons and a kilometer across per each geosynchronous satellite, with 10 kilometer antenna's on the ground to receive the focused beam.

Getting that much stuff in to a geosynchronous orbit and constructing such large structures there will be a challenge.

In my opinion, utterly impractical (without some cheap ground-to-orbit science fiction magic, like a space elevator). Too expensive to build and maintan (as you suggest), and then there's the politically sensitive issue of "beaming" those kinds of power levels down at the earth from space.

In my opinion (again), we need to be focussing on the low-cost/low-maintenance/low-complexity end of things. Anything on the other end of the spectrum had better be a really high-quality source of power, and terrestrial.

[Ghent12]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

In my opinion, utterly impractical (without some cheap ground-to-orbit science fiction magic, like a space elevator). Too expensive to build and maintan (as you suggest), and then there's the politically sensitive issue of "beaming" those kinds of power levels down at the earth from space.

In my opinion (again), we need to be focussing on the low-cost/low-maintenance/low-complexity end of things. Anything on the other end of the spectrum had better be a really high-quality source of power, and terrestrial.

I disagree. With enough capital investment, such a system could indeed work. Satellites and orbital bodies are designed to require no maintenance (with very few exceptions) and historically exceed their lifetime expectations. So long as the unfounded concern with regards to safety is ignored or addressed theatrically, this is one potential route towards much greater sustainability.

[Jay]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

In my opinion (again), we need to be focussing on the low-cost/low-maintenance/low-complexity end of things. Anything on the other end of the spectrum had better be a really high-quality source of power, and terrestrial.

Sure, like conservation. That is the largest and easiest fruit to harvest, by a mile. It's like preventative medicine, unsexy, but effective, so no one is willing to look at it seriously. Can the world act rationally for once or do we need to burn the forest down first?

[ASH]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

I disagree. With enough capital investment, such a system could indeed work. Satellites and orbital bodies are designed to require no maintenance (with very few exceptions) and historically exceed their lifetime expectations. So long as the unfounded concern with regards to safety is ignored or addressed theatrically, this is one potential route towards much greater sustainability.

I grant you that with "enough" capital investment, anything not forbidden by natural law can be accomplished. The question should probably be whether the capital investment required to make this work is greater than or less than other potential solutions. Both space-based power stations and potential new terrestrial energy technologies require substantial R&D to bring to fruition -- however, the terrestrial solutions don't have the logistical burdens imposed by working in space.

While it is true that satellites are designed to require no maintenance, it does not follow that it is practically possible to build an orbital solar power station that requires no maintenance. The total number of components -- many of which must be high-power devices -- would make it much harder to build a no-maintenance plant.

I have worked on characterizing space radiation damage to photodiodes, and have some familiarity with radiation hardening techniques for CMOS circuitry, but my experience has no specific application to solar cells. It did, however, prompt me to wonder about the typical lifetime on orbit. I found this plot of the efficiency degradation of solar cells on orbit, expressed as a percentage of the maximum possible efficiency at one astronomical unit (a.u.) from the sun (not power conversion efficiency). The cyclic structure in the graph results from the orbital motion of the geosynchronous satellite relative to the sun, but the downward trend in efficiency results from cumulative radiation damage. The text of the link says that after an initial rapid drop in the first year, current solar cells lose about 2% of their efficiency (relative to maximum) per year.



There would also be a maintenance issue related to collisions with 'space junk'. According to a reference cited by this article on space debris, "Large-scale structures, like solar power satellites, would be almost certain to suffer major collisions over short periods of time."

The political issue with beaming power to earth isn't a technical safety issue -- that can easily be dealt with by failsafe circuitry that breaks the space-ground link if the beam wanders off target. I admit that this is somewhat speculative, but the political issue I see is that various nations might perceive the power stations as potential space-to-ground directed energy weapons.

Mind you, I'm all for developing difficult technology. I'm even for developing challenging technology and achieving engineering feats of limited practical value, simply because engineering and science are expressions of cultural greatness and the human spirit... rather like climbing a mountain or funding a nice symphony hall. I just don't think I'd put money on space-based solar power as being the low-cost alternative energy solution that wins.

[unlucky]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

I grant you that with "enough" capital investment, anything not forbidden by natural law can be accomplished.

Another variation on the theme is the moon-based approach, proposed by e.g. physicist David Criswell. He claims to have done the sums to show that this can be built economically today with existing technology. See overview linked here.

[SamAdams]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

See Space based solar power (wikipedia) for further details. These things would be friggin huge. Something like 50 or 80 tons and a kilometer across per each geosynchronous satellite, with 10 kilometer antenna's on the ground to receive the focused beam.

Getting that much stuff in to a geosynchronous orbit and constructing such large structures there will be a challenge.

One option that could reduce the cost of launch is lunar based solar power. The Wikipedia article doesn't talk too much about the lunar solar power concept by Dr. David Criswell but here is some more info:
http://www.thespacereview.com/article/354/1

There is not too much mass represented by a solar cell. Almost all of the mass is taken up by silicon, which is plentiful on the Moon. The energy to refine the silicon is also plentiful. Thus the case for LSP is very robust to changes in the cost of transport. Even at ten times Criswell’s assumed cost to Earth orbit of $500/kilogram, building out the Moon would assure that the cost of energy never rises higher than it is today. That is a pretty good assurance. And once there is $500 billion a year or more in commerce on the Moon, it would be reasonable to assume there would be sufficient traffic for lower cost heavy lift to be affordable and fully utilized, making the low-cost case of Lunar development govern.

[SamAdams]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

Another variation on the theme is the moon-based approach, proposed by e.g. physicist David Criswell. He claims to have done the sums to show that this can be built economically today with existing technology. See overview linked here.

Sorry I missed your post before and also posted a link to lunar power....

[c1ue]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

In my opinion, utterly impractical (without some cheap ground-to-orbit science fiction magic, like a space elevator). Too expensive to build and maintan (as you suggest), and then there's the politically sensitive issue of "beaming" those kinds of power levels down at the earth from space.

Actually in my view the beaming is the primary problem.

If jetliners filled with fuel can bring down skyscrapers, what could megawatt or gigawatt power beams do?

For that matter what is the difference between said 'power' beams and weapons systems?

Destructive capability: check
Pinpoint guidance system: check
Huge global footprint: check

Admittedly power satellites are softer targets than a missile silo in North Dakota...but then again they would be fantastic first strike weapons: light speed from orbit.

[big67]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

In my opinion (again), we need to be focussing on the low-cost/low-maintenance/low-complexity end of things.

Completely agree. First rule of engineering design: what is not included does not break down and does not require maintenance...

[thriftyandboringinohio]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

Actually in my view the beaming is the primary problem.

If jetliners filled with fuel can bring down skyscrapers, what could megawatt or gigawatt power beams do?

For that matter what is the difference between said 'power' beams and weapons systems?

Destructive capability: check
Pinpoint guidance system: check
Huge global footprint: check

Admittedly power satellites are softer targets than a missile silo in North Dakota...but then again they would be fantastic first strike weapons: light speed from orbit.

Despite my normal tone as an engineering curmudgeon at iTulip, this one seems almost feasible.

True enough, such a power utility could be used as a beam weapon. But that helps the economics; much of the basic technology is dual-use and many of the details of station keeping and power beam focus may exist now from SDI. There is also the sunk-cost angle - we have NASA space centers full of people and hardware sitting around now trying to justify their existance, why not put them to work on this? I say go to a phase one study on this one.

[c1ue]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

Despite my normal tone as an engineering curmudgeon at iTulip, this one seems almost feasible.

True enough, such a power utility could be used as a beam weapon. But that helps the economics; much of the basic technology is dual-use and many of the details of station keeping and power beam focus may exist now from SDI. There is also the sunk-cost angle - we have NASA space centers full of people and hardware sitting around now trying to justify their existance, why not put them to work on this? I say go to a phase one study on this one.

My point was that other nations are not unaware of the dual use aspect - how do you think they would react to potential first strike orbital weapons being deployed?

Conversely how would the US react to an orbital power station by another nation?

[thriftyandboringinohio]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

My point was that other nations are not unaware of the dual use aspect - how do you think they would react to potential first strike orbital weapons being deployed?

Conversely how would the US react to an orbital power station by another nation?

I don't see it being a problem. The G20 are likely all capable of some anti-satellite strike. The US certainly is. This system would be a big, slow lumbering target, and not much of a threat for a surprise attack. To move it from it's permanent location to strike Bejing or Moscow would take a day or two - this thing would be acres of structurally fragile panels not ammenable to sudden acceleration. While the individual sub-systems and devices are dual-use, the entire system as a whole would be a pretty poor weapon system.

[KGW]

Re: Boondoggle or future of energy? Space Based Solar Power TED talk

I wonder how many developing countries would have to be "democratized" to source this "capital."

I disagree. With enough capital investment, such a system could indeed work. Satellites and orbital bodies are designed to require no maintenance (with very few exceptions) and historically exceed their lifetime expectations. So long as the unfounded concern with regards to safety is ignored or addressed theatrically, this is one potential route towards much greater sustainability.