The current interest in Space Based Solar Power (SBSP) is opening the way to an eruption of projects. The permanent sun illumination met in Geostationary Earth Orbit (GEO) could enable the cost per continuous watt to be competitive with ground based like solar and wind. There have been a number of assumptions made in the various studies and reports, encompassing technological, development, validation, deployment, operational and financial point of views.
A new paper delivers a first order evaluation of the power management, conversion, distribution and wireless transport aspects and to show that, from this technical point of view, the feasibility of gigawatt size SBSP systems is everything but established. A brief assessment of some other aspects is also provided, going in the same direction. Altogether, the conclusion is that the analyses about the economic and environmental benefits of SBSP, sometimes extremely detailed, are built on a technical ground far from being solid enough to make them credible.
The PDF for the Henri Barde study is not publicly available without purchase.
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And the pink elephant in the room is the power transfer. Nobody has demonstrated anything approaching what of needed. Or proved me wrong by linking to a source….
https://www.space.com/space-solar-power-satellite-beams-energy-1st-time
Demonstrated one foot distance transmission. A factor of one hundred million short of what is needed…
https://ssi.org/solar-power-satellites/sps-reports/
If I’m not mistaken, they tested high power decades ago on the ground between to separated antennas. The efficiency was fairly high in this limited test. The attack on Lahaina shows they can beam down power effectively.
Your second link goes to a site with more than a thousand pages. Please be more specific if you have some data about demonstrated power breaming over relevant distances. The data should contain information about distance and efficiency.
Please note that a few meters, or even a kilometre is not relevant, since the target distance is 36000 km!
I do recall a power transfer test between two dish antenna on Earth, a long while back. More recently: https://www.powermag.com/mhi-demonstrates-wireless-power-transmission/
The problem with these tests at ground level is that a real system would have to go through the ionosphere. Since that’s actually, (Unlike the lower atmosphere.) a conductive plasma, you have a lot of potential for interactions there. And the test needs to be at full power, the interactions are unlikely to be linear.
Your best bet would probably be to test power transmission upwards, your sensors would be a LOT cheaper to loft than the transmission equipment. Just dump a huge load of cubesats to pass through the beam above the ionosphere and record the beam strength.
The ground level equipment would be fairly pricey, as while the individual antennae elements would be cheap enough, you’d need a filled array covering many acres, and transmitting GW for a real full scale test.
Such a system would have serious weapons potential, though only against targets passing over it. Maybe, though, it could be used to dispose of orbital debris?
I’ve seen proposals to use solar panels in deserts to generate power that is beamed up to a relay station, then back down to a point of use.
Over a certain distance, losses are, (predicted to be) less than line transmission
Your point on the ionosphere being a problem is valid.
[ means, energy being transmitted 2x through atmosphere
knowing from solar irradiation input, atmosphere absorbs ~19% of incoming electromagnetic spectrum’s energy (top of atmosphere ~1366W/m², because of geometric and reflective surfaces, (atmosphere_67, land&water_168 W/m² are directly absorbed) ~235W/m², Greenhouse gas absorption ~350W/m², all Greenhouse warming (Greenhouse gas, land&water heat emissions) summing up a warming heat input at ~450W/m²)
Meanwhile solar&battery&(cheap)’rangeExtender backup’ seems more reasonable (compared to space arrays&network, electromagnetic distribution&transmission, Earth network(&storage&backup)? ]
[ Average Daily Global Horizontal Irradiation (kWh/m²) ‘https://resourcewatch.org/data/explore/2063964b-56c8-4080-b2a5-5a7710f321b9?hash=layers§ion=Discover&selectedCollection=&zoom=2.0605240991346307&lat=10.450554087679052&lng=-42.27624342401198&pitch=0&bearing=0&basemap=dark&labels=light&layers=%255B%257B%2522dataset%2522%253A%25222063964b-56c8-4080-b2a5-5a7710f321b9%2522%252C%2522opacity%2522%253A1%252C%2522layer%2522%253A%25220bb499a3-3a09-4461-a8d6-295b8491cd5a%2522%257D%255D&aoi=&page=1&sort=most-viewed&sortDirection=-1’ ]
Space-based power generation can have a dual use as a space weapon. How will that be monitored? Will countries like China or Russia allow oversite to ensure power beaming doesn’t target cities?
Given satellites in geostationary, the only way you could really weaponize them is if you had a large number of satellites and aimed them all at the same city. Beamed power from that distance would be less concentrated than sunlight. The only reason it still makes sense is that the ground collector for microwaves is very cheap, with antenna wire in place of solar cells.
As of the tech a decade ago, achieving even that much focus from a phased array transmitter required a reference signal from the ground target.
The ground reference signal doesn’t have to be from the target, though. You just need one, once you have it you can impose an offset, and focus the beam somewhere else.
The real limit is antenna size; If the antenna is just large enough to achieve a useable power density on a rectenna, you know they can’t further focus it to weapons level intensity. If somebody starts building an SPS with a grossly over-sized antenna, then you know before it’s finished that it’s intended to be usable as a weapon.