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Sigmetnow

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Solar Power from Space? It’s complicated.
« on: June 22, 2021, 09:04:42 PM »
Solar Power from Space? It’s complicated.

All that free power from the sun up in space, available all day, every day — as long as you are not in the earth’s shadow.  Why can’t we capture it and send it to earth?  Some day, it might be possible, but there are many obstacles….

<< Recap and continuation of a discussion which has been deleted from the Electrical Grid thread.  Feel free to add your two cents and correct anything I’ve said wrong! >>

The first thought that might come to mind is a using satellite with a huge array of solar panels, which orbits the earth and beams down power to a receiving station.  The first problem is:  due to the earth’s strong gravity, the super slow orbit that would take ~24 hours to complete (and thus keep a satellite constantly over the same spot on the earth), is only available at 35,000 km (22,000 miles) away from the earth.  This is why geostationary internet satellites have such terrible latency — because to stay in one spot as earth rotates, so that fixed rooftop dishes will always point to it — the signals must travel far out into space, then all the way back.
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Wikipedia:
A geostationary orbit can be achieved only at an altitude very close to 35,786 kilometres (22,236 miles) and directly above the equator. This equates to an orbital speed of 3.07 kilometres per second (1.91 miles per second) and an orbital period of 1,436 minutes, one sidereal day. This ensures that the satellite will match the Earth's rotational period and has a stationary footprint on the ground. All geostationary satellites have to be located on this ring.
https://en.wikipedia.org/wiki/Geostationary_orbit

Due to the earth’s gravity, satellites in orbit closer than this must move faster, to prevent them from falling back to earth. 

For example, the International Space Station in Low Earth Orbit circles the earth at a distance of about 250 miles [400 km].  It must maintain a speed of about 17,000 miles per hour [5 miles per second; 8 kps] to stay at that altitude.  And that speed results in an the station circling around the earth every 90 minutes.

If the ISS slowed, gravity would pull it down until it succumbed to reentry.  The station’s precise orbital speed at that altitude is what’s required to prevent the station from flying away from earth, or being pulled down to it.

Stable orbits require you going fast enough, in a direction pointed away from earth, so that you continually “fall toward earth but miss it.” ;)   

20 second video:
https://twitter.com/tyler0309/status/1397629811951128587

—-
Yeah, but it would be better if the satellite were closer
To orbit closer to the surface, at approximately the edge of space (100 km) and not be pulled down to earth would require a speed of 7.84km/sec.  This is much faster than the earth rotates — it theoretically would circle the earth every 87 minutes — but it would be stable only for a few minutes before collapsing.

https://en.wikipedia.org/wiki/Newton%27s_cannonball

https://www.freemars.org/jeff/speed/index.htm
 
—-
This is why we hear “Vehicle is pitching downrange” a few seconds after a rocket clears the launch tower.  Because orbits require “sideways” speed. A bullet fired straight up might reach orbital velocity… but then gravity would pull it right back down.

Orbital mechanics:  it’s the law! :)

If we launched a spacecraft straight up to the edge of space and wanted it to “hover” in place, it would require, essentially, a rocket engine firing forever, with just enough thrust at altitude to match the weight of the spacecraft, the rocket — and its crap-ton of forever fuel.  Consider what is required to keep an airplane or helicopter over one spot.  Much energy and fuel burned, and not able to be maintained for long.

—-
Near-earth power transfer from space might require a constellation of Low Earth Orbit satellites, each one beaming down power as it passed over an earth receiving station…. 

—-
There are proposals for “Geostationary Balloon/Airship Satellites”, floating in the mid-stratosphere (~70hPa).  But I see winds of up to 30 to 90kph at 70hPa altitude today, a relatively calm day, which would mean a lot of energy would be needed to remain in place, and quite a challenge to maintain a large array of solar panels, especially if an array is held up by multiple ships.  A solar array on the earth’s surface could be much larger, less vulnerable to the elements, and not require any energy to just remain in place.
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Geostationary balloon satellites (GBS) are proposed high-altitude balloons that would float in the mid-stratosphere (60,000 to 70,000 feet (18 to 21 km) above sea level) at a fixed point over the Earth's surface and thereby act as atmosphere analogues to satellites.
https://en.wikipedia.org/wiki/High-altitude_balloon

—-
What else? Some new kind of solar satellite? Laser links to send power to satellites on the dark side? Space batteries? How would power be transmitted from space down to earth?  What about clouds?  And how much Prohibited Airspace (it’s a thing) would be needed to keep airplanes away from where they might get burned up by it, let alone other satellites?
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NeilT

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Re: Solar Power from Space? It’s complicated.
« Reply #1 on: June 22, 2021, 09:24:35 PM »
Sig I did some reading about the thoughts on this.  35km to LEO is not a real problem because very short microwave can deliver a huge amount of power over long distances due to the lack of an atmosphere.

The LEO satellites can then beam it down to earth using lower frequencies and guidable transmitters.

There are benefits to space.  Much more of the solar power gets absorbed by the panels and is usable due to the lack of atmosphere.  Far enough out and the panels can get sun 24x7.  But bringing it down to earth loses up to 50% of the energy.

I was thinking that with low loss transmission, outside the atmosphere, with a sufficient number of downlink transmitters, power could be beamed wherever it is needed without needing the huge infrastructure of HVDC cables under the sea.

It is worth thinking about, at least.

There is quite a lot of research and information about top of atmosphere dynamics.  There is virtually zero wind or current or drag or anything like that.  The main problem with it is getting up there then staying up there.  Something the US military tried very hard to do and failed miserably.

Google wanted balloons for internet, due to the very low altitude it became prohibitive.

There is, possibly, a place for this tech, but it would require a level of space infrastructure which is, to our current technology, the equivalent of building the great pyramid with bare hands.

Loads of thoughts there though.  Like if you get 100% more energy for 100% more time and lose 50% of it on the downlink, you are still 100% up on the energy you were getting for the same panels.

Most analysis focuses on the loss.  Not on the opportunity.

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Re: Solar Power from Space? It’s complicated.
« Reply #2 on: June 22, 2021, 10:08:17 PM »
I read somewhere that geosynchronis orbits are essentially full over densely populated areas.

Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #3 on: June 23, 2021, 12:48:41 AM »
I was thinking that with low loss transmission, outside the atmosphere, with a sufficient number of downlink transmitters, power could be beamed wherever it is needed without needing the huge infrastructure of HVDC cables under the sea.

Totally agree with this.  What with all the Bluetooth, and Qi charging, etc., cables seem so… last century.  We may not have the technology quite yet, but with access to space becoming more affordable, there will be more interest in figuring out how to transmit power and radio signals, next door and around the globe, without using cable or fiber.  Phased array antennas used to be very expensive gear, used mainly by the military, but now SpaceX Starlink is bringing them to the common consumer.

If we can transmit power at a distance in space, there will be no need to have large solar arrays in LEO — they can be some distance away in a sun-synchronous orbit that may not look like a traditional “orbit.”  Check out the planned path of the once and future James Webb telescope:

https://twitter.com/nasawebb/status/1405948904538001417
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Tor Bejnar

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Re: Solar Power from Space? It’s complicated.
« Reply #4 on: June 23, 2021, 01:11:15 AM »
Cross post below:
To minimize losses of transferring energy gathered in outer space to Earth's surface, would a dirigible parked at about 20 km up provide a platform to relay energy beamed from on high down to Earth?  From the Sceye website:
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We chose the form factor of an airship over balloons and fixed wing aircrafts as it allows for geostationary capability while lifting and powering far more payload than any other platform.

And good news:  Sceye has job openings!
Sceye, New Mexico consortium tests OpenRAN in the stratosphere for tribal broadband service
Quote
A Swiss high-altitude platforms (HAPS) company Sceye recently conducted a test flight of its sleek, silvery stratospheric blimp with the aim of covering rural and tribal areas of New Mexico with 100 Mbps-level speeds.

Sceye’s HAPS achieved an elevation of 64,000 feet during a two-hour test flight last Wednesday, and the company also recently conducted tests to determine the range of its Open RAN-based LTE coverage. Sceye said that its tech allows OpenRAN-based LTE to reach a range of up to 140 kilometers — which it claims is “a long-range record in LTE OpenRAN architecture” — and 40 km beyond what standard LTE would be expected to achieve. It says that it will be able to cover “areas as wide as 27,000 square miles with high-speed broadband for all users of fixed and mobile, carving a path forward to providing true equitable access.”

“We view the successful flight and the record setting data connection as a significant milestone for our technology; one that could dissolve the rural broadband barrier,” said Sceye CEO Mikkel Vestergaard Frandsen. Frandsen founded Sceye in 2014 to focus on the possibilities of solar-powered HAPS for providing broadband service as well as improving environmental and disaster monitoring.
...

See more information on this European Space Agency site. "Sceye Services Enabled by HAPS Complemented by Satellite"
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NeilT

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Re: Solar Power from Space? It’s complicated.
« Reply #5 on: June 23, 2021, 03:35:27 PM »
In all of my reading, you need to get over 30km in order to get out of the issues with remaining stationary, i.e. you burn your budget of fuel trying to remain on station and force either refuel or to land and replace the lift vessel.

Although my thinking was that with a power conduit, burning hydrogen with oxygen, in a closed loop system, would give you endless propulsion fuel if you cracked the water back to hydrogen and oxygen using a small portion of the power going through the relay.  Food for thought.

But this kind of vessel has a huge problem which is the loss of lift gas.  Eventually it leaks and eventually it has to be refilled.

Most LTA vehicles are designed to lift, go somewhere and land.  This kind of infrastructure would need to be fixed, long term.

I managed to make a contact through work to talk about my idea on that.

My thoughts revolve around a vessel which can reach 70km or more, never have to come down and be able to keep itself in position as needed.  That kind of vessel could hold the required downlink transmitting circuitry on the bottom and the high frequency receiving circuitry on the top.

Enough of those and you have the requisite infrastructure for space based power to be viable.

Another consideration is that the higher losses of power down to earth come from using frequencies which are not harmful.  However there are places in the world where harmful frequencies are not an issue.  Allowing for less loss and greater power delivery.

It is an interesting field.
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Tor Bejnar

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Re: Solar Power from Space? It’s complicated.
« Reply #6 on: June 23, 2021, 09:54:38 PM »
Did you read
Quote
Sceye is solar powered during the day and battery powered at night. We don’t rely on rocket fuel like satellites or single use plastics like balloons.
Quote
We chose the form factor of an airship over balloons and fixed wing aircrafts as it allows for geostationary capability while lifting and powering far more payload than any other platform.
Quote
Our hull fabric in comparison to the nearest alternative used by others in attempts to build the stratospheric platform
     5 times stronger relative to weight
     1500 times more gas tight
     UV and ozone resistant
Quote
Our advanced lithium-sulphur battery
     Energy density more than 400 Wh/kg
     2 times greater energy density than best electric vehicles
     400 Wh/kg is the threshold at which airplanes go electric
That's their hype.  I don't know!  (I've just been a fan of dirigibles ever since I first read Nevil' Shute's Slide Rule: Autobiography of an Engineer in 1972.)

They don't appear to be 'just' some crazy Swiss hanging out in the New Mexico desert! (They're also crazy Swiss doing things with the European Space Agency.)

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NeilT

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Re: Solar Power from Space? It’s complicated.
« Reply #7 on: June 24, 2021, 03:27:04 PM »
Yes I know that they are putting a huge amount of effort into this.  But the point is that there is no such thing as a fully gas tight envelope for helium or hydrogen.  Also, at 20km, there is the statistical certainty that it will be overwhelmed by winds at that altitude.  From my reading you need to get over 38km before you can start to discount atmospheric drag from wind storms.

It is a fantastic advance on existing technology.  But it is limited by its very own design, which means it uses a lift gas which cannot be replaced whilst in flight without resupply.

Most of my reading says you need to be in the mesosphere to achieve truly viable operational capability as wind problems found in the stratosphere are rare.

The airship being worked on here falls into a category of long duration middle atmosphere flight.  To truly get to space based solar power we'd need permanent middle atmosphere platforms which are geostationary, locked to one place on the earth.

Having permanent platforms of this type would allow orbiting solar power farms to beam onto the required downlink platform for transmission of the power to earth.

Of course, even with this helium kind of ship, given the electric nature, it could borrow from the beamed power stream to hold itself in place and, thus, need minimal battery capacity.

However it still suffers from helium loss and helium is a finite gas.  For fixed operation hydrogen would be a far better choice.  Given that the platform would not be carrying passengers or low flying around populated areas.

Still not my idea but this is better than many others.
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Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #8 on: June 24, 2021, 04:13:29 PM »
Just came across this graphic, which may help here until I find something better….
Click to embiggen.
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Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #9 on: June 24, 2021, 04:48:39 PM »
How much lift does a hydrogen or helium balloon generate at stratospheric altitudes? 

Per wikipedia, high altitude balloons generally attain stratospheric altitudes “between 18 and 37 km (11 and 23 mi; 59,000 and 121,000 ft) above sea level. In 2002, a balloon named BU60-1 reached a record altitude of 53.0 km (32.9 mi; 173,900 ft).”
https://en.wikipedia.org/wiki/High-altitude_balloon

It’s one thing for a balloon to lift itself, and maybe a small package of instruments, to the stratosphere.  But attach high-power transmitters, receivers, antennas, batteries… and thrusters?, fuel, and fuel generators? … and the balloon has to lift much more than its own weight.  (Big satellites weigh several tons!)  I have a hard time seeing airship power maintaining anything similar at a high altitude, in place, using current technology. 

Change my mind. ;)
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NeilT

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Re: Solar Power from Space? It’s complicated.
« Reply #10 on: June 24, 2021, 05:23:19 PM »
How about this one?



It gives an idea of what can get to where with current technology.
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NeilT

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Re: Solar Power from Space? It’s complicated.
« Reply #11 on: June 24, 2021, 05:36:24 PM »
Change my mind. ;)



That is 2.7 tons.

https://www.nasa.gov/scientific-balloons/types-of-balloons

Quote
Scientific balloons can lift up to 8000 lbs. (3600 kg), which is approximately the weight of three small cars!

I would expect commercial platforms to be a LOT bigger than a science balloon and stay up for a LOT longer.  It is, for instance, the difference between the Montgolfier brothers balloon and the Graf Hindenburg series.

I would also expect that the commercial application would be able to stay up for years.

So it is being done for tens of days to an altitude which is viable.  When pushing the envelope, it is worth aiming a lot higher.

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Tor Bejnar

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Re: Solar Power from Space? It’s complicated.
« Reply #12 on: June 24, 2021, 07:05:45 PM »
Thank you Neil for your several comments.
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Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #13 on: June 24, 2021, 07:50:06 PM »
Good info, Neil. Thanks!
Quote
That is 2.7 tons.

But only at altitude for a few days, or a couple months at most, right?  Even the longest duration in your table is 100 days.

Importantly:  those balloons are in simple free-flight, not stationary. 

“Thrusters at station-keeping, Captain.”

The Inmarsat I4 F3 communications satellite was a hefty 5960kg.
 Weather satellite (DMSP) weighs just over 4,500lbs total.

Just saying, powerful tech is much heavier than we’d like.  NASA rejected the Dynetics moon lander proposal because they determined it would require “negative mass”….
      
Quote
I would expect commercial platforms to be a LOT bigger than a science balloon and stay up for a LOT longer. …

I would also expect that the commercial application would be able to stay up for years.

So it is being done for tens of days to an altitude which is viable.  When pushing the envelope, it is worth aiming a lot higher.

It would have to be — much heavier than a science pack, and at altitude for much longer — but I still don’t see how it could be done.  Not saying it never will be done!  But I see no current technology that could lift a heavy power station to high altitude and keep it there, fixed over one spot.  In fact, have we seen any lighter than air craft that can station-keep in the stratosphere for months at a time?

Let’s keep looking.
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NeilT

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Re: Solar Power from Space? It’s complicated.
« Reply #14 on: June 24, 2021, 09:49:39 PM »
You're right, it has not been done.  Getting above the stratosphere solves the station keeping, there is virtually zero wind.  The reason it has not been done is because current tech is only aiming for the stratosphere because that is easier to get to.

Staying up?  Now that's a big one.  You need a lift envelope which can be maintained without resupply.  I have thoughts about that.  I'll find out, shortly, if others see it the same way.  Well hopefully.

But, no, nobody is doing that today. They're still trying to do what the incumbent automotive industry is doing.  Leveraging 100 year old technology with 21st century materials.  They need to take 21st century tech and create a new look at what they're doing.
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Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #15 on: August 03, 2021, 10:20:54 PM »
—- Revealed:  Space-based Solar Power Project (SSPP)
Quote
Eric Berger
Now that the cost of access to space is coming down it's important to actually have meaningful things to do with it. Space-based solar power certainly qualifies. Excited to see where this goes.
https://twitter.com/sciguyspace/status/1422638198618984453
 
Quote
Caltech
Today, we announce a $100M gift from Donald Bren, chairman of Irvine Company and a Caltech lifetime trustee, to form the Space-based Solar Power Project (SSPP).

The goal: Develop technology to capture solar power in space for use on Earth.
https://twitter.com/caltech/status/1422626285356912641
 
Caltech Announces Breakthrough $100 Million Gift to Fund Space-based Solar Power Project
Quote
Today, Caltech is announcing that Donald Bren, chairman of Irvine Company and a lifetime member of the Caltech Board of Trustees, donated over $100 million to form the Space-based Solar Power Project (SSPP), which is developing technology capable of generating solar power in space and beaming it back to Earth.

SSPP aims to ultimately produce a global supply of affordable, renewable, clean energy. A key benefit of harnessing solar power from space is that it provides access to the sun to create power all day, every day, free from weather constraints or darkness of night.

The project's first test, which will occur in early 2023, will launch technology prototypes for the solar power generators and RF wireless power transfer, and includes a deployable structure measuring roughly 6 feet by 6 feet. … 
https://www.caltech.edu/about/news/caltech-announces-breakthrough-100-million-gift-to-fund-space-based-solar-power-project

Space Solar Power Project
Quote
Collecting solar power in space and transmitting the energy wirelessly to Earth through microwaves enables terrestrial power availability unaffected by weather or time of day. Solar power could be continuously available anywhere on earth.
Our concept is based on the modular assembly of ultralight, foldable, 2D integrated elements. Integration of solar power and RF conversion in one element avoids a power distribution network throughout the structure, further reducing weight and complexity. This concept enables scalability and mitigates local element failure impact on other parts of the system.

Most recently we demonstrated the lightest (by an order of magnitude) integrated multifunctional prototype which collects sunlight, converts it to RF electrical power, then wirelessly transmit that power in a steerable beam.
 
RESEARCH
Our research solves the fundamental challenges associated with implementing space solar by integrating ultralight and shape accurate structures with high efficiency photovoltaics and large scale phased array power transmission into a two dimensional scalable, deployable spacecraft.
https://www.spacesolar.caltech.edu/
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Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #16 on: August 03, 2021, 10:29:29 PM »
Space-based Solar Power | ACT of ESA
https://www.esa.int/gsp/ACT/projects/sps/

Solar Power Satellite concept
Space based solar power satellites (SPS) are large structures in space that convert solar energy, captured as solar irradiation, into a form of energy that is transmitted wirelessly (WPT) to any remote receiver station. This receiver could either be on Earth, or on a high altitude platform (aircraft), other spacecraft or even on the surface of the moon or other planets. The original idea took form in the 1970's by the Czech-US engineer Dr. Peter Glaser and ever since a variety of studies have been undertaken. These studies have led to a large diversity of concepts which use different forms of power generation, conversion and transmission principles.

How is the power transmitted to Earth?
Currently the so-called reference design transforms solar power into electricity via photovoltaic cells in geostationary orbit around Earth. The power is then transmitted via electromagnetic waves at 2.45 GHz to dedicated receiver stations on Earth, "rectennas", which convert the energy back into electricity used in the local grid.

How much power can solar power satellites deliver?
The power range of the concepts for SPS is from a few tens of MW to several hundred of GW. Just for comparison purposes, a modern standard nuclear power plant delivers about 1 GW and the energy need for Europe in 2020 is estimated to be about 500 GW. If we can come close to the theoretical transmission efficiencies via electromagnetic waves (50-60%) then we could produce around 400W electricity per square meter on Earth receivers, which is about two to three times the amount we could receive from the same area of terrestrial PV panel. Furthermore, this would be produced continuously, day and night.

The advantages and disadvantages of a space-based system
One of the main advantages of a solar power station is the continuous power generation. Unlike the day-night cycle of solar arrays on Earth, a SPS in geostationary orbit 35786 km above earth will continuously face the sun and provide a constant output over time. The solar irradiation (W/m2) outside of the Earth's atmosphere is also slightly higher. The continuous energy supply will also put much less stringent demands on the storage capabilities, which are in general large and expensive. A second advantage is obtained by the wireless power transfer to any location on the planet. This will remove the requirements of a large-scale electricity grid and allows for dynamically allocating power to the regions where it is required. A possible third advantage is the level geopolitical playing field in which the energy is equally collected and distributed by all participating countries.

Clearly, one of the main challenges for any space-based solar power satellite is the construction of large structures in orbit. Not only does it require significant amounts of material to be launched into space, these materials will need to be assembled, maintained and possibly replaced over time. In fact, due to the harsh space environment, the lifetime of current solar panels in space is significantly shorter compared to the Earth surface. A second complication is related to the wireless power transmission to the Earth surface, which requires transmission via electromagnetic waves at high transfer efficiencies. To stay below safety limits, this will require very large diameter receiver antenna's (or rectenna's), although in comparison to earth bases solar arrays the total area coverage will be smaller.
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Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #17 on: January 05, 2022, 05:22:04 PM »
Russia studies
Quote
Eric Berger
Russia is apparently funding studies of space-based solar power. However there is zero indication in this news release that funding exists for actual development of hardware.

Stas Klymenko
This is the most common situation for Roskosmos.
They talk about concepts but never end up building them. Same situation with:
- Russian orbital station.
- RU/CN lunar station.
- Sphere (Starlink analog)
- Superheavy Enisey
- Orel/Federation spaceship

Eric Berger
Yes, it's depressingly consistent.
1/5/22 https://twitter.com/sciguyspace/status/1478708502835171329

Quote
РОСКОСМОС @roscosmos
[Translated:] Solar power plant!  RCC scientists have proposed an alternative to traditional energy ☀️

The development will ensure the regular supply of alternative electricity to remote areas of the Earth, regardless of weather conditions and time of day: roscosmos.ru/33810/
1/5/22 https://twitter.com/roscosmos/status/1478629606580264968
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morganism

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Re: Solar Power from Space? It’s complicated.
« Reply #18 on: April 23, 2022, 11:10:58 PM »
US Navy wirelessly beams 1.6 kW of power a kilometer using microwaves

(...)
Using a 10-GHz microwave beam, SCOPE-M set up at two locations. The first was the US Army Research Field at Blossom Point, Maryland, and the second was at the Haystack Ultra Wideband Satellite Imaging Radar (HUSIR) transmitter at MIT in Massachusetts. The frequency was chosen because it was not only able to beam even in heavy rain with a loss of power of under five percent, it's also safe to use under international standards in the presence of birds, animals, and people. This means the system doesn't need the automatic cutouts developed for earlier laser-based systems.

In the Maryland tests, the beam operated at an efficiency of 60 percent. The Massachusetts test didn't reach the same power peak, but had a higher average power level, so more energy was delivered."

"Although SCOPE-M was a terrestrial power beaming link, it was a good proof of concept for a space power beaming link," said Brian Tierney, SCOPE-M electronics engineer. "The main benefit of space to Earth power beaming for the DOD is to mitigate the reliance on the fuel supply for troops, which can be vulnerable to attack."

https://newatlas.com/energy/us-navy-beams-1-6-kw-power-kilometer-microwaves/

Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #19 on: April 26, 2022, 05:37:56 PM »
The video below describes huge satellites in geostationary orbit, with panels made from mass-produced modules which are assembled in space by autonomous robots, each satellite requiring an earth (ocean surface?) receiving footprint of only 3% of an offshore wind farm.

The video says:
Each satellite converts sunlight to radio waves, delivering 2 gigawatts of continuous power to earth, equivalent to a conventional power station. The beam is safe, with a strength one-quarter of that of the mid-day sun, and requires a receiver footprint (shown floating in the ocean) of only about 3% of an offshore wind farm.
Each satellite is very big, but made from thousands of small modules to keep costs down. “Transported to orbit by a fleet of reusable rockets” — deployment by a SpaceX Starship is shown — then autonomous robots assemble the panels together on orbit.  Energy delivered should be about the same cost as power from solar panels on earth — but Space Based Solar Power continues at night.

Space Based Solar Power: Helping to deliver Net Zero


1 month ago. 3 minutes.
Quote
The Space Energy Initiative will bring together government, research and industry in the space and energy sectors to develop and deliver a co-ordinated programme of technology development and demonstration.

Meeting the timeline set out by the Government’s Net Zero pledge, and in partnership with other nations, the aim is to establish the first orbital demonstrator SBSP system by 2030, with the first of a kind operational system delivering power into the grid by 2040.

A constellation of Solar Power Satellites would be in operation by the mid 2040s, delivering a substantial proportion of the UK’s energy needs.


The UK wants SpaceX to help it launch a $20 billion orbital solar power station
The first demonstrator could reach orbit by 2030.
Quote
The U.K. government is considering building a £16 billion ($20.8 billion) orbital solar power station, a report from TheNextWeb reveals.

The government recently released its Net Zero Innovation Portfolio, which includes a section on space-based solar power. It is one of several potential solutions aimed at helping the country achieve its goal of net-zero emissions by 2050.

The project, called the Space Energy Initiative (SEI), aims to set up the first power station in space by 2035. …

Space-based solar power
There are several key obstacles that must be overcome before the U.K.'s orbital space station can become a reality. Firstly, much like China's system, tests are required to verify the safety of the technology. The main questions that need answering are how will such a high-frequency energy beam affect communications, air traffic control, and the well-being of nearby residents? China has so far conducted tests from altitudes of 980 feet (300 meters) using hot air balloons and soon aims to carry out 20km-range experiments using an airship.

The cost and emissions of sending such a large station to orbit is also a potential obstacle for a project that's aimed at lowering the cost of renewables and achieving climate goals. This is where the U.K. hopes the world's leading satellite launcher, SpaceX, will help out. In an interview with the Daily Express, Conservative MP, Mark Garnier recently said, "They (the satellites) are going to be in the magnitude of tens of launches in order to get these things into orbit, and you have got to get the assembly unit up there as well." …
https://interestingengineering.com/uk-launch-solar-power-station

EDIT:
⬇️ From the video: Looks like several of the solar power satellites are focussed on each Earth receiving grid.
Reminder: A geostationary orbit can be achieved only at an altitude very close to 35,786 kilometres (22,236 miles) and directly above the equator.
« Last Edit: April 27, 2022, 02:13:04 PM by Sigmetnow »
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morganism

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Re: Solar Power from Space? It’s complicated.
« Reply #20 on: April 26, 2022, 11:45:00 PM »
Beaming solar power from satellite array is Earth Day focus for AFRL
by Rachel Delaney for AFRL News
Kirtland AFB NM (AFRL) Apr 22, 2022

Video: Space Solar Power Incremental Demonstrations and Research Project (SSPIDR)

In honor of Earth Day, the Air Force Research Laboratory, or AFRL, is highlighting its efforts toward harnessing the Sun's energy, converting it to radio frequency, or RF, and beaming it to the Earth providing a green power source for the U.S. and allied forces.

Key technologies need to be developed to make such a challenging process a reality.

In response to this challenge, AFRL formed the Space Solar Power Incremental Demonstrations and Research, or SSPIDR, project to develop the critical technologies needed for such a system. These technologies include further improving solar cell efficiencies; solar to RF conversion and beam forming; reducing large temperature fluctuations on spacecraft components; and deployable structure concept designs.

"A major objective of SSPIDR is to break the one-meter-squared aperture threshold for solar power capture and conversion, and beam that energy to the ground," said James Winter, AFRL principal engineer and SSPIDR project manager. "AFRL will do this with Arachne, SSPIDR's keystone flight experiment that is anticipated to launch in early 2025."

Other demonstrations of the target technologies include the Space Power INcremental DepLoyables Experiment, or SPINDLE, - a deployable structures experiment still undergoing trade studies, and the Space Power InfRared Regulation and Analysis of Lifetime, or SPIRRAL, experiment - a thermal experiment exploring the concept of using variable emissivity materials to reduce the large temperature swings experienced by spacecraft components on orbit. SPIRRAL is anticipated to launch in 2023 for a test campaign onboard the International Space Station."

https://www.solardaily.com/reports/Beaming_solar_power_from_satellite_array_is_Earth_Day_focus_for_AFRL_999.html

Space Solar Power Incremental Demonstrations and Research Project (SSPIDR)


morganism

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Re: Solar Power from Space? It’s complicated.
« Reply #21 on: May 27, 2022, 12:53:33 AM »
Spooky Power at a Distance

 Practical Power Beaming Gets Real

A century later, Nikola Tesla’s dream comes true

(not much new here, but listing of lots of companies working on it.)

https://spectrum.ieee.org/power-beaming

Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #22 on: May 29, 2022, 07:57:44 PM »
NASA plans to reexamine the feasibility of space-based solar power, an approach that is finding new support based on lower launch costs, technological advances and interest in clean energy sources.
 
NASA to reexamine space-based solar power
Jeff Foust May 28, 2022
Quote
WASHINGTON — NASA is starting a study to reexamine the viability of space-based solar power, a long-touted solution to providing power from space that may be getting new interest thanks to technological advances and pushes for clean energy … the first by the agency in about two decades.

“As the technology has evolved, the feasibility of the system has changed over time,” he said. “This study is going to assess the degree to which NASA should support space-based solar power.”

The study will not attempt to come up with a new architecture for SBSP, but instead reexamine past concepts for collecting solar energy in space and transmitting it to the ground for conversion to electricity. Those updated systems will be compared to terrestrial power systems and assess policy and implementation challenges they face.

It will also look at the costs of such systems, which traditionally has been a major stumbling block in previous studies dating back to the 1970s. “It’s going to be a lot of money, but money is not the only driver here,” he said. “If the number is huge and staggering, that might be OK.”

Advance[ments] in several technical areas, Joseph said, give the agency reason to at least reexamine the feasibility of SBSP. “The elephant in the room is launch costs, and launch has become significantly more accessible. That completely changes the way we look at this,” he said. Other areas that have seen advances include thermal systems, electronics, materials and solar panels.


There has been a revival of interest in SBSP in recent years, including a workshop last December by the European Space Agency that Joseph said NASA attended and which led the agency to consider its own study. The British government included SBSP as a technology it was exploring alongside nuclear, wind and other energy systems last year.

Much of that interest is driven by the desire for energy sources that can achieve goals of “net zero” carbon emissions to mitigate climate change. “I think it’s one of the more promising things that we can do from a space perspective to help save the planet. We’ve got to get to 2050 net-zero,” said Karen Jones of The Aerospace Corporation’s Center for Space Policy and Strategy during a later panel on SBSP at the conference.

“It just doesn’t make any sense for the United States to not be looking at this,” said Peter Garretson, a former U.S. Air Force officer who led a study on SBSP by the now-defunct National Security Space Office in 2007. He cited both climate change as well as international competition, including reported Chinese interest in SBSP.

“Even if you were to assume that space solar power would not end up being economical, the fact that we are losing the narrative by not trying for something on a global agenda just makes us look silly,” he argued.

John Mankins, a longtime advocate for SBSP who led earlier NASA studies on the topic, said “super cheap” space access promised by vehicles like SpaceX’s Starship changed the economics of such system. “Transportation is no longer part of the cost equation,” he said. “That makes space solar power potentially affordable, depending on how you do it.” …
https://spacenews.com/nasa-to-reexamine-space-based-solar-power/
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Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #23 on: August 16, 2022, 07:43:41 PM »
—- ESA wants to lead on Space-Based Solar Power (SBSP)
  But…
Quote
Eric Berger: 
Europe's chief space official says his agency intends to lead the way on development of space-based solar power.
8/16/22, 10:57 AM. https://twitter.com/sciguyspace/status/1559554867475226625
 
Quote
Josef Aschbacher
It will be up to Europe, @esa and its Member States to push the envelope of technology to solve one of the most pressing problems for people on Earth of this generation. Much will be on the table at #CM22.

Josef Aschbacher
At #CM22, I will propose a SBSP preparatory programme to Member States called #SOLARIS. We have the main building blocks already, but let me be clear: for the project to succeed, much technology development and funding is still needed. esa.int/Enabling_Suppo… pic.twitter.com/raqf9ZcRht
[Infographic at the link.]
8/16/22, 10:52 AM https://twitter.com/aschbacherjosef/status/1559553716738527232

< Eric, I know you are just reporting what has been said, but what do you think? Surely this has to be a non-starter for the financials, let alone everything else.
 
Eric Berger
I'm not sure what to think. I would welcome a government at least taking a crack at the concept, however. (China has already indicated its interest, as well).
8/16/22 https://twitter.com/sciguyspace/status/1559571525560565760

<  I just hope they start doing the math and realize they need a massive, fully reusable launch vehicle to get it anywhere close to making sense. The sooner they realize they need to build a European Starship competitor the better.
<< That's literally what ESA did a few weeks ago, they starting asking the industry about a European reusable heavy lift launcher:
 
Quote
Since writing, @esa_sts has updated the PROTEIN ITT increasing the projected capability of the system from 1,500 t per year to 10,000 t per year. That's a significant update! I have changed the web version to reflect it.
7/18/22 https://twitter.com/andrewparsonson/status/1549081261708382208 [/size]

 
ESA posted a new video today:
SOLARIS: Preparing for space-based solar power - YouTube
4 minutes. Includes what appears to be a reusable, heavy-lift ESA-branded rocket booster [with SpaceX-Falcon 9-like landing legs and diamond-shaped grid fins above 8)].  Look closely for the SpaceX Dragon! 
 


——
Quote
< I've seen an interview with @elonmusk where he bluntly states that putting solar panels in space and beaming the energy back to earth is not a useful idea. (and he rhetorically states that if there's anyone who should be excited about the idea, it's him)
8/16/22 https://twitter.com/danielbigham/status/1559556787937939459
 
Casey Handmer explained why the financials don’t work, back in 2019.
 
—- Space-based solar power is not a thing
Casey Handmer, August 17, 2019
Quote
… As Elon Musk has concisely pointed out, the fundamental problem with space-based solar power is that it’s obtaining a commodity, power, somewhere where it’s expensive and selling it somewhere where it’s cheap. This is not a good business. Indeed, it might make more sense to beam power from Earth to space stations, if they needed it.


What are the extra costs? Broadly, they fall into the following categories: Transmission losses, thermal losses, logistics costs, and space technology penalty. Individually, any one of these issues cancels out the benefits, and combined they leave space-based solar power at least three orders of magnitude more expensive than the terrestrial equivalents. Because it’s not even close, I don’t have to be persnickety about decimal places – instead I can rely on generously drawn bounds.


Today, I can pick up the phone and any of dozens of contractors in the LA market can fill hundreds of acres with panels, each built to survive 30 years under the harsh sun and sized perfectly for deployment using the latest tech, which is men in orange vests with forklifts.

In contrast, space technology has not benefited from such breakneck levels of growth, demand, and investment. Prohibitive maintenance costs demand perfect performance, and low rates of deployment ensure a slow innovation feedback loop. The result is that none of the current incredibly cheap solar panels could work in space, where thermal and vacuum, not to mention stresses of launch, would destroy their operation in days.

Instead, space operators rely on more traditional supply chains, with the result that building anything for space takes years and costs billions. Right now, a billion dollars invested will buy about 100MW of solar panels on the Earth, or 100kW of solar panels in space. This is a factor of 1000, and it also erases the advantages of more sunlight in space.

These four elements, transmission, thermal, logistics, and space technology, inflate the relative cost of space-based solar power to the point where it simply cannot compete with terrestrial solar. It’s not a matter of 5% here or there. It’s literally thousands of times more expensive. It’s not a thing.
https://caseyhandmer.wordpress.com/2019/08/20/space-based-solar-power-is-not-a-thing/
« Last Edit: August 16, 2022, 07:59:54 PM by Sigmetnow »
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Tor Bejnar

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Re: Solar Power from Space? It’s complicated.
« Reply #24 on: August 16, 2022, 10:15:27 PM »
How sad!
😥
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Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #25 on: August 17, 2022, 03:02:37 AM »
How sad!
😥

Why not take the money earmarked for SBSP and build 1000 times that solar power right here, right now, on Earth?

Keep up the R&D, ramp up heavy-lift reusable rocket flights until they are commonplace, and maybe in a couple decades, SBSP will make sense.
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Sigmetnow

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Re: Solar Power from Space? It’s complicated.
« Reply #26 on: August 17, 2022, 04:46:07 AM »
—- ESA SBSP, continued
Quote
Eric Berger
Europe did some cost-benefit studies on the potential of space-based solar power.
The UK firm Frazer-Nash used an interesting rocket as part of its graphics package.
esa.int/Enabling_Suppo…
8/16/22, 5:37 PM. https://twitter.com/sciguyspace/status/1559655578754060298
⬇️ Infographic and emphasized section.
 
Quote
Eric Berger
Would love to see @CJHandmer's reaction to these studies as I find his dismissal of space-based solar power to be fairly persuasive.
caseyhandmer.wordpress.com/2019/08/20/spa…

Casey Handmer, PhD @CJHandmer
But I read here it's rock solid:
Quote
Josef Aschbacher @AschbacherJosef
Space-based Solar Power would be an important step towards carbon neutrality and energy independence for Europe. Two recent independent studies strongly recommend investments to advance the SBSP technologies needed to address our growing energy crisis: esa.int/Enabling_Suppo…

Casey Handmer, PhD @CJHandmer
I have not read this particular proposal in detail but I will and I will find its error. I think it's pretty irresponsible to be promoting this sort of nonsense when Europe is in the grips of a real energy crisis.
  —
[ 2 hours later … ]
I couldn't find any techno economic estimates so that was easy.
  —
Almost always these studies either overstate future demand, make wildly unjustified assumptions about learning rate, or fail to account for price shifts in competing methods. Often all three. That's if they get far enough to actually make an estimate.
  —
LCOE suspiciously close to the projected wholesale cost (assuming 0% financing, 90 year payback period, 98% reduction in launch costs, 100% regulatory approval, zero marginal cost microwave transmission, 99% reduction in...
  —
... manufacturing costs, solar and wind power cost growth, the non-existence of battery technology, and our team of novices hitting every development milestone 2 months early and under budget.)"
8/16/22, 6:43 PM. https://twitter.com/cjhandmer/status/1559672327956099073

Quote
< Space based power would be useful on the Moon though. Powersats placed at Lagrange points could deliver uninterrupted power to lunar industries anywhere on the surface.
8/16/22, 7:01 PM. https://twitter.com/john_gardi/status/1559676755778101253
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morganism

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Re: Solar Power from Space? It’s complicated.
« Reply #27 on: September 10, 2022, 01:38:13 AM »
solar-powered lasers to new heights with four-mirror pumping

 In a recent study published in the SPIE Journal of Photonics for Energy, researchers from Algeria and Portugal report a new solar-powered laser design that successfully addresses these issues. This laser has an improved laser conversion efficiency compared to those pumped with conventional sources (such as flash lamps and LEDs).

"The approach we adopted in this study allowed us to develop a powerful solar-powered laser operating in TEM00 mode, the fundamental or lowest-order mode," explains Associate Professor Dawei Liang from Universidade Nova de Lisboa in Portugal, the corresponding author of the study. "Each of these modes (our laser sustains multiple fundamental modes) can be precisely controlled with minimal heat input to the pump cavity. This enables us to tailor the applied energy to the specific needs of an application," he adds.

The researchers performed numerical simulations to optimize the design parameters of a TEM00-mode Nd:YAG solar laser beam. Further, they used four laser rods inside four 2V-shaped pump cavities, and pumped them with sunlight using four large off-axis parabolic mirrors with a total collection area of 10 m2."

 One of the major potential applications of this design concerns space-based solar power generation. This involves collection of solar energy in outer space, converting it to a laser beam, and sending it down to Earth where it can be utilized to generate electricity using solar cells. Since this process is not influenced by the Earth atmosphere, it is more stable and requires smaller transmission and receiving equipment than those needed in microwave power transmission.

Liang notes that while a photovoltaic-powered diode-pumped laser still has greater solar-to-laser conversion efficiency than that of a solar laser, it is much less suitable for long-term space applications. This is because a diode-pumped laser has a limited diode pump source lifetime and a more complex laser system. A solar-powered laser enjoys far greater system simplicity, and benefits from a nearly eternal and free pump source.

Overall, this study lights a way to take solar-powered lasers to new heights, with a clear blueprint for high-efficiency, space-ready solar lasers."

https://www.solardaily.com/reports/Taking_solar_powered_lasers_to_new_heights_with_four_mirror_pumping_999.html

https://www.spiedigitallibrary.org/journals/journal-of-photonics-for-energy/volume-12/issue-03/038002/Efficient-TEM00-mode-solar-laser-using-four-Nd-YAG-rods/10.1117/1.JPE.12.038002.full?SSO=1