Seriously, ESA? Wireless energy transfer bullshit on a cosmic scale - Page 1
Forum section: electronics / general

author: Keri Szafir
author_rank: Contributor
timestamp: August 23, 2022, 04:07:53 pm
content: When you thought you've seen it all, there's another one coming...https://arstechnica.com/science/2022/08/european-space-chief-says-continent-will-lead-in-space-based-solar-power/Transmitting such power over a light or microwave beam? The way I see it...1. The efficiency of power conversion on transmitting and receiving ends2. Clouds obstructing the beam and absorbing energy3. Focusing and alignment: a concentrated light beam would have to hit the precise spot, otherwise it's more waste and cause thermal damage4. Safety: a tens or hundreds kilowatts power microwave beam?5. The cost and effort of putting something as big up there in the orbit6. Serviceability and maintenance

author: helio0centra@gmail.com
author_rank: Contributor
timestamp: August 29, 2022, 11:29:44 pm
content: One of those ones that Dave debunked on the EEVBlog You Tube channel: Wi-Charge, uses an infrared laser. And it's efficiency is something like 10%. So the amount of energy you would need to convert and broadcast on the satellite would be ridiculous. And for any useful amount of received energy on the ground it would have to be a very dangerous beam that if you missed the target by a fraction of a degree you would have something like a sci-fi disaster movie.

author: Haenk
author_rank: Super Contributor
timestamp: August 30, 2022, 09:48:35 am
content: Plus one should always remember: There is plenty of landmass on earth available - with no population around at all.Mongolia, Sahara, Namibia are technically not too far away from major energy consuments; Australia has more than enough space, too. North/south America has plenty of free space as well.So there is no reason for complex space projects with dodgy energy transfers.

author: tszaboo
author_rank: Super Contributor
timestamp: August 30, 2022, 09:55:28 am
content: The project might be worth it for the alternative applications. Changing the beam's target could be a mayor deterrent, and might be funded from the military's budget, that we were going to spend anyway.

author: Haenk
author_rank: Super Contributor
timestamp: August 30, 2022, 10:18:08 am
content: Quote from: tszaboo on August 30, 2022, 09:55:28 amYou mean something like a James-Bond-ish Space Laser?

author: tszaboo
author_rank: Super Contributor
timestamp: August 30, 2022, 10:44:18 am
content: Quote from: Haenk on August 30, 2022, 10:18:08 amFor sure it wouldn't be so drastic, with vulcano bases and diamonds. A 100MW plant would only be able to heat up an object weighing 50 tons made out of steel by 5K/sec, so it would take about half a minute to a minute to heat it up to be unusable. Depending on how well it might track fast moving objects, that travel let's say 4KM/sec, it would be suitable to disable those in lesser time, maybe 1 sec or so, making those obsolete. Or better, disable the launch platforms on the ground. And deter other users of assembling such power generation platforms.

author: coppercone2
author_rank: Super Contributor
timestamp: November 09, 2022, 08:45:24 am
content: this was considered seriously by NASA, and used in several episodes of startrek. It has been studied as far back as the 1920's (all the Japanese secret death ray conspiracies of WW2)I welcome our orbitaldefensepower transfer particle beamcannonsatellite networkwhat can go wrong?https://web.archive.org/web/20051023080942/http://www2.univ-reunion.fr/~lcks/Old_Version/PubIAF97.htm

author: Haenk
author_rank: Super Contributor
timestamp: November 09, 2022, 12:19:07 pm
content: Funny, how that satellite with 10 squaremeters of panels will generate such an enormous powerbeam.But that's fricking NASA, so who am I to raise doubts.

author: Marco
author_rank: Super Contributor
timestamp: November 09, 2022, 12:21:23 pm
content: The most practical design I can come up with is a heliogyro, with the wings being thin film PV and a klystron in the middle. Very light weight, the wings hold themselves in tension due to centrifugal force.

author: David Hess
author_rank: Super Contributor
timestamp: November 09, 2022, 12:24:37 pm
content: Quote from: Keri Szafir on August 23, 2022, 04:07:53 pmThe total efficiency only needs to be high enough, and the efficiency at the receiving end is much higher than with solar photovoltaic. The transmitting side uses a Klystron or similar but maybe solid state is feasible now.QuoteSome will be absorbed, but still better than sunshine.QuoteThe beam is neither coherent nor tightly collimated.QuoteThe power density is pretty low. The receiving antenna takes quite a bit of area. Think of it as photovoltaic solar, but with much higher efficiency at the receiver and only a couple times the energy density.QuoteIt would be expensive, but compared to the alternatives not too expensive.QuoteThere is nothing mechanical to wear out.Quote from: helio0centra@gmail.com on August 29, 2022, 11:29:44 pmEfficiency is better than with solar photovoltaic, and the power density is not high enough to be instantly dangerous. You stand in sunlight, right?