spectrum.ieee.org/space-based-solar-power-2667878868
Space-based solar power as a concept has been building some momentum. But the technical and logistical problems pointed out here seem to end any hopes for this solution to the climate crisis. Unsurprisingly, it seems more like an idea that's being sold to us.
The question remains: what does a healthy green transition look like? What's "enough" power and how would it be generated in a world that doesn't rely on fossil fules?
SSP emerged in the midst of the first Energy Crisis riding a popular misconception --propagated by the oil industry, conservatives, and even some nit-wit school teachers-- that there wasn't enough land surface on Earth to ever meet our energy needs with solar power and, somehow, there would never be a practical way to store energy for use overnight or on cloudy days... Something a little math could have easily debunked and which completely ignored the full spectrum of renewable energy systems at our disposal. And so building solar arrays in space, where space seems unlimited and solar is about 40% higher in yield, seemed like a logical solution. Then and now the essential problems with the concept are the same; its creation and maintenance relies on a host of technologies and in-space industrial capability that don't yet exist, aren't really being worked on present, and whose development time and costs never get brought into the picture, rectenna arrays take up almost as much contiguous land area as mass commercial solar and must be remotely located creating the same distribution logistics problems as terrestrial solar, and it reestablishes the same hegemony of northern industrial countries and their corporations (now in the form of spacefaring superpowers) over the world energy infrastructure as exists with fossil fuels.
What, at first, greatly sold the idea of SSP was the fantasy of space colonization as depicted by Gerard O'Neill in his classic space futurism books like The High Frontier and elaborated on by many others of the time. Given our culture at the time, the proposition of space colonization needed a commercial rationalization, but that's a problem when there really is no practical way to get space resources or products to the Earth's surface in bulk. (again, high school physics can tell you why that will not likely ever happen. Mass at orbital velocity represents a lot of energy you have to dissipate into the atmosphere as heat to get it to the ground --and then there's all the pollution and energy/carbon spent collecting all those payloads, if you aren't further increasing mass with a soft-landing system)
Enter SSP which offered the prospect of turning space resources into a commodity that could be conveniently beamed to Earth as microwaves, thus economically rationalizing the creation of these gigantic rotating space colonies as 'company towns' for a presumed army of workers and their families mining the Moon and asteroids to build and maintain orbital solar arrays. Unfortunately, by the late '90s the Energy Crisis had become a fading memory after being exposed as a grand corporate grift, it had become quite apparent that launch costs were not declining as --forever-- predicted (space agencies failing to demonstrate that reusable spacecraft could save any money), and suited EVA wasn't actually useful for any real work nor likely to ever become so. If we were ever going to build and maintain such gigantic things in space, that work would have to be done with robots controlled from Earth itself, which put the hero-astronauts out of work and precluded any need for company towns in space, making the gigantic space colonies commercially pointless again. Well, that's no fun so the space advocacy community more-or-less gave up on the notion and turned their attention to Mars and the cultivation of a cosmo-humanist philosophical system to rationalize manned space activity when money and utility couldn't, though it has remained on the back shelf to be trotted out whenever someone again tries to find a commercial rationalization for grandiose space development visions.
As for what a green energy transition looks like, I refer again to that Land Art Generator site and this updated article and map looking at the broader renewables picture. They've done a pretty-good job of the back-of-the-envelope math, though they still don't account for some available but undeveloped technology like OTEC. But the basic story here is that it doesn't demand that drastic a change to our civilization's footprint, doesn't demand some untenable land area, nor does it require any speculative super-technology only and handful of superpower nations might be able develop. Fundamentally, SSP is redundant and offers no particular advantages. It just delays and distracts from what is doable right now, with tools at-hand, while burning through a lot of money and time. SSP is to the energy transition what self-driving has proven to be to the EV transition.
I worked on SSP rectennas for the army a few decades ago. The promise of SSP is actually for flexability in emergency power, aircraft power, and military power. Most uses of SSP are in fact in space.
But other than space and possibly military uses, the downsides of SSP are not because of SSP. It's because for most uses there is a cheaper and more robust terrestrial option.
For instance our fabric rectenna tent covers were better used for receiving power from an adjacent mountain instead of from space or an aircraft. Regardless, solar panels with giant batteries were cheaper.
SSP will be amazing in space, and for power assistance to electric assisted launch rockets. In theory.... In practice, not so much.
As is typical of such criticisms, this is a straw man. The premise is that rocket launches are too expensive. This is assuming rockets are required for access to orbit.
Electromagnetic launch is far lower in cost for bootstrapping industrial space solar. After you build the first high energy beam, subsequent payloads are delivered to orbit via the beam of concentrated energy.
Tethers are another approach. Rockets being the weakness of the plan is a strawman, it is a form of deception whether intentional or not
Hey trying to stay open to lots of perspectives, but don't want to spread misinformation.
Electromagnetic launches, while theoretically possible are not in any way a proven technology for space applications and certainly would not be cheaper than rocketry to develop infrastructure for (individual launches maybe, infrastructure, development, and testing, definitely not). It is as yet an unsolved problem in aerospace. Not to mention, the acceleration required to generate all of the necessary delta-v to get to orbit before you leave the ground would react absolutely absurd stresses through any structures you were trying to launch which would mean you would need to further rigidize your structure which then requires even more energy to hit your target dv, not to mention the destructive effects on your launch system.
Transporting any materials on a "beam of energy" or "by tethers" are both not feasible. For one, the photonic pressure exerted by light is tiny. You could not generate enough lift to move a payload of any appreciable size without dumping truly atmosphere destroying levels of power into a beam, and at that point you have likely vaporized your payload as well. If we had tethers strong enough to support their own weight to orbit, not to mention a payload, we would be building space elevators, not any of the other solutions. Alas, we have no such tethers at the present time.
I appreciate your enthusiasm for the issue, but sadly, solutions are rarely so simple. I think when you put it in perspective it is hardly a leap to say mega-structures thousands of times the size of the most expensive structure ever produced by mankind (the ISS) would be very expensive. We can hardly convince politicians to fund proven social programs here on earth, let alone spend trillions of dollars on unproven technologies.
Source: I have a masters degree in aerospace engineering focusing on space systems and robotics.
The key criticism isn't launch. It's a broad range of technical and logistical limitations that make terrestrial power sources far easier to accomplish.
Chief among all of them: if you're selling this power, it doesn't make financial sense for companies to buy it considering they could get it cheaper elsewhere.
Thank you for your submission, we appreciate your efforts at helping us to thoughtfully create a better world. r/solarpunk encourages you to also check out other solarpunk spaces such as https://wt.social/wt/solarpunk , https://slrpnk.net/ , https://raddle.me/f/solarpunk , https://discord.gg/3tf6FqGAJs , https://discord.gg/BwabpwfBCr , and https://www.appropedia.org/Welcome_to_Appropedia .
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.