Caltech researchers demonstrate wireless solar power transmission in space

[Alfonso Maruccia]

What just happened? The global race to beam solar energy from space directly to Earth is raging on, and Caltech scientists have seemingly scored the first goal. The SSPD-1 has successfully harvested solar power in space, wirelessly transmitting it at close distance and then "lighting" a sensor on the Earth's surface.

The ability to harvest solar energy in space is one of the most sought goals for solving the many energy problems we have here on Earth. An orbiting satellite fleet could theoretically provide an endless source of clean, electromagnetic energy, but the technology is still in its prototype stage even for the most advanced ventures like Caltech's Space Solar Power Project (SSPP).

Now, scientists at the California research institute claim they have been able to wirelessly transmit solar power in space. The Caltech SSPP team tested the Space Solar Power Demonstrator (SSPD-1) prototype that was launched into orbit in January, and they were able to successfully demonstrate the MAPLE experiment for energy harvesting and transmission.

MAPLE, which is short for Microwave Array for Power-transfer Low-orbit Experiment, is one of the three key experiments aboard the SSPD-1 prototype. The device is provided with an array of flexible lightweight microwave power transmitters, driven by custom-built microchips based on low-cost silicon technologies. The array can beam and direct energy to desired locations, Caltech said, while the flexible design was adopted to minimize the amount of fuel needed to send the satellite into space.

MAPLE includes two separate receiver arrays installed a foot away from the transmitter, which were used to receive the collected energy, convert it into direct current (DC) electricity, and finally light up a pair of LEDs to show that the wireless energy transmission was working as intended. "No one has ever demonstrated wireless energy transfer in space even with expensive rigid structures," Caltech scientists said, and now the SSPP team is doing it with their own integrated circuits.

The last part of the MAPLE experiment is a small window through which the array can beam the energy to Earth. The Caltech researchers installed a receiver on the roof of the Gordon and Betty Moore Laboratory of Engineering on the university's campus, and they were able to detect the beam transmitted from space. The SSPP team said flexible power transmission arrays are essential if they want to achieve the vision for a constellation of sail-like solar panels that unfurl once they reach orbit.

According to SSPP co-director Ali Hajimiri, wireless energy transfer (from space) has the power to effectively democratize access to energy. No energy transmission infrastructure would be needed on the ground to receive this power, Hajimiri said, which means that a satellite fleet could "send energy to remote regions and areas devastated by war or natural disaster" – regardless of weather conditions or daylight availability.

Besides MAPLE, the SSPD-1 prototype includes two other experiments which are still waiting for their time to shine: DOLCE (Deployable on-Orbit ultraLight Composite Experiment) is a six feet by six feet structure designed to demonstrate the "architecture, packaging scheme, and deployment mechanisms" of the modular spacecraft; ALBA is a collection of 32 different types of photovoltaic cells that help determine which types of cells can best withstand the harsh conditions of outer space without losing their efficiency.

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https://www.techspot.com/news/98997-caltech-researchers-demonstrate-wireless-solar-power-transmission-space.html

 

[SweatyLoveJuice]

I guess the US governments Directed Energy Weapons are most likely another conspiracy theory that has been proven true....If US tech has this now, the gov did 30 years ago.

 

[Kashim]

I guess the US governments Directed Energy Weapons are most likely another conspiracy theory that has been proven true....If US tech has this now, the gov did 30 years ago.

Boy, that's a pretty big logical leap you took there. If some company has a barely working prototype of something now then obviously the "gumment" already had it 30 years ago and is currently using it as a space weapon. But of course! Ergo, conspiracy theory proven true. And using the transitive property of conspiracy theory proof we can assume that ALL conspiracy theories are therefore true. Please adjust your tinfoil hat, some of the crazy might be leaking out.

 

[Kashim]

What these articles never talk about is what happens when something gets in the way of these beams. Say, an airplane, or birds, or thick clouds. What happens then? While all of it sounds very cool and science fiction-y, I fail to see any practical applications for this in the coming decades. Not only does it require extreme precision, but there are also just too many things that can go wrong. We can spend lots of research dollars on pie in the sky ideas like this, and space elevators, cold fusion, etc. but we have yet to see any of these fantastical ideas come to fruition.

 

[cristianm]

What these articles never talk about is what happens when something gets in the way of these beams. Say, an airplane, or birds, or thick clouds. What happens then? While all of it sounds very cool and science fiction-y, I fail to see any practical applications for this in the coming decades. Not only does it require extreme precision, but there are also just too many things that can go wrong. We can spend lots of research dollars on pie in the sky ideas like this, and space elevators, cold fusion, etc. but we have yet to see any of these fantastical ideas come to fruition.

I believe at this point the low hanging fruits have been harvested. So, while some ideas are not practical, we have to investigate and split the big problem into smaller ones that we can solve one by one. Maybe energy harvesting from space is not useful now, or maybe never for earth because of the atmosphere, clouds, birds and planes and other things. But the building blocks could be used for something else or somewhere else. Solar cells were developed for space, and we now use them for generating part of our energy.

 

[Badvok]

Wireless solar power transmission in space = Exactly what the Sun does.

Or am I somehow missing something?

 

[Plutoisaplanet]

Wireless solar power transmission in space = Exactly what the Sun does.

Or am I somehow missing something?

I’m completely spitballing here based on how I’d think it works… But I think it’s more of a concept of creating a much higher output of the energy from sun in a specific area. Plus much of the sun’s light is reflected by our atmosphere (how much, idk) and whatever wavelengths are retransmitted could be chosen based on what our atmosphere is poor at blocking. Last, light could be directed to somewhere where it’s night/evening to match demand with the desired energy generation curve.

Seems like something up Elon Musk’s alley. But definitely a concern is risk to bystanders in the directed path (midair), or if this thing misses/malfunctions somehow.

 

[cristianm]

Wireless solar power transmission in space = Exactly what the Sun does.

Or am I somehow missing something?

You are right, the sun sends energy, but the output is on the surface of a sphere so it diminishes quite fast by 4*pi*R^2. If they can send energy coherently to some meaningful distance they may able to harvest energy closer to the sun and send it where it is needed.
Another advantage is the radiance at some point in space is constant, whereas on a planet it varies wildly (from day to night, from season to season). So having a solar farm in space and being able to send that energy where needed is more like having a reliable power source than the finicky solar farms on the ground we use today.

 

[Freddie159]

I guess the US governments Directed Energy Weapons are most likely another conspiracy theory that has been proven true....If US tech has this now, the gov did 30 years ago.

My buddy worked for the US Government in the 70's and 80's and they were writing how to papers on this back then, it was for disaster areas where there was NOTHING that they could depend on once they put boots on the ground.

 

[Freddie159]

You are right, the sun sends energy, but the output is on the surface of a sphere so it diminishes quite fast by 4*pi*R^2. If they can send energy coherently to some meaningful distance they may able to harvest energy closer to the sun and send it where it is needed.
Another advantage is the radiance at some point in space is constant, whereas on a planet it varies wildly (from day to night, from season to season). So having a solar farm in space and being able to send that energy where needed is more like having a reliable power source than the finicky solar farms on the ground we use today.

So you are talking about a global power company that gathers power as the Sun moves around the World providing it to underdeveloped places? Here now there then as the World turns.

 

[Philip BM]

So nobody here played Sim City 2000? https://simcity.fandom.com/wiki/Microwave_Power_Plant

 

[dmatheson]

What these articles never talk about is what happens when something gets in the way of these beams. Say, an airplane, or birds, or thick clouds. What happens then? While all of it sounds very cool and science fiction-y, I fail to see any practical applications for this in the coming decades. Not only does it require extreme precision, but there are also just too many things that can go wrong. We can spend lots of research dollars on pie in the sky ideas like this, and space elevators, cold fusion, etc. but we have yet to see any of these fantastical ideas come to fruition.

Pretty sure you could make that argument for technologies that we now use every day. Just like start-ups, new technologies have the similar calculus, one hopefully is a unicorn, 2 will sell and make a profit, 3 will break even and 5 will die...or some similar ratio. You don't know what you don't know about new technologies and how they can be applied and you don't know what you'll discover along the journey of development. If everyone had your attitude, we'd still be using rocks.

 

[dmatheson]

Pretty sure you could make that argument for technologies that we now use every day. Just like start-ups, new technologies have the similar calculus, one hopefully is a unicorn, 2 will sell and make a profit, 3 will break even and 5 will die...or some similar ratio. You don't know what you don't know about new technologies and how they can be applied and you don't know what you'll discover along the journey of development. If everyone had your attitude, we'd still be using rocks.

For instance, people thought others were crazy proposing lithium batteries...you know, lithium blows up. Now everyone is carrying around a lithium battery. I'm not saying there still aren't some valid arguments NOT to be doing that but that's the evolution of the beast.