Caltech joins the wireless energy hype - Page 1
Forum section: electronics / general

author: madires
author_rank: Super Contributor
timestamp: June 07, 2023, 03:56:29 pm
content: Satellite beams solar power down to Earth, in first-of-a-kind demonstration:https://www.science.org/content/article/satellite-beams-solar-power-down-earth-first-kind-demonstrationTL;DR: They transmitted 200mW of microwaves from a satellite to earth.

author: AVGresponding
author_rank: Super Contributor
timestamp: June 07, 2023, 05:03:25 pm
content: Is that the transmitted power, or the received power? I would suspect the latter, and the transmitted power was several orders of magnitude larger...

author: TimFox
author_rank: Super Contributor
timestamp: June 07, 2023, 05:52:38 pm
content: As is usual, this was a demonstration of a practical module that can be scaled up for use in spacecraft.Seehttps://www.caltech.edu/about/news/in-a-first-caltechs-space-solar-power-demonstrator-wirelessly-transmits-power-in-spaceAs Werner Herzog once titled a film, "Even dwarfs  started small"https://www.imdb.com/title/tt0065436/

author: Sredni
author_rank: Frequent Contributor
timestamp: June 07, 2023, 06:14:25 pm
content: I remember a Donald Duck comic where Uncle Scrooge places a 'solar umbrella' into orbit to beam down solar power to his money bin. Them pesky Beagle Boys ruined it.

author: helius
author_rank: Super Contributor
timestamp: June 07, 2023, 06:32:16 pm
content: As players of "SimCity 2000" will know, when the satellite solar collector beam wanders from its designated receiver station, lots of fires are started. We should think carefully about whether we want megawatts of microwave energy aimed at us.

author: Ranayna
author_rank: Super Contributor
timestamp: June 08, 2023, 08:10:57 am
content: Quote from: madires on June 07, 2023, 03:56:29 pmThey did *not* transmit down 200mW down to Earth. They transmitted 200mW within the satellite, over a distance of less than half a meter. They then turned the transmitter towards earth and were able to detect it.Sadly, there is no mention about the power of the transmitter, i infer from the article, and others i have read about this, that 200mW was the received power.Quote from: helius on June 07, 2023, 06:32:16 pmYes, that was exactly were my thought went toThat damn microwave power station, while clean, so often burned down the area around itAnd if this thing has an aimable beam, the potential for misuse is staggering. Literal Space Lasers....

author: Haenk
author_rank: Super Contributor
timestamp: June 08, 2023, 09:45:58 am
content: Good thing is: Before investing billions and more billions, there *might* be a discussion in advance if one should just buy 100 times the generated power by installing solar panels on, say, flat ground.

author: Marco
author_rank: Super Contributor
timestamp: June 08, 2023, 10:52:08 am
content: Much more money is going into PV, hydrogen and methanation ... but storage add a big cost multiplier to PV.Is it big enough to justify satellite power beaming? Almost certainly not, but it doesn't hurt to do a little exploration of the solution space. Maybe a space gun would drastically reduce launch costs of materials? You never know.

author: Marco
author_rank: Super Contributor
timestamp: June 08, 2023, 10:55:54 am
content: Quote from: Ranayna on June 08, 2023, 08:10:57 amYou can't really go small for any real testing, to get sufficient beam quality you need a huge phased array ... and if the transmitter is huge, even with a good beam the receiver needs to be huge squared.It's better to just do it all in sim, none of it is rocket science.PS. you can do mmWave I guess to at least get 1 order of magnitude in size reduction for a scale model, but at the same time the phased array and antennas become much more complex, it's not worth it.PPS. I wonder what's the most efficient way to build a huge phased array. Could you just have an oscillator at every patch antenna and sync it to a modulated signal from earth? No need to program anything, no need for communication across the array, array deformation is automatically corrected for?

author: jonpaul
author_rank: Super Contributor
timestamp: June 08, 2023, 11:00:48 am
content: Old idea,1960s MPSS rectenna Glasser,https://www.osti.gov/servlets/purl/1650318Could be used as a weapon as wellJon