Energy Supply in Solar System vs Productive Use

tahanson43206 · 2021-06-19 18:27:49

The human race is (hopefully) very early in its development.

At present, some members of the population perceive a poverty of energy, and claim that whatever energy is available is being consumed faster than it is being captured.

I was curious to see if Google might be able to provide some facts to work with.

Inquiry regarding energy passing Earth

Google ... how much energy does the sun produce?

About 337,000,000 results (0.83 seconds)
The sun releases energy at a mass–energy conversion rate of 4.26 million metric tons per second, which produces the equivalent of 384.6 septillion watts (3.846×1026 W).Dec 14, 2015
How does the sun produce energy? - Phys.org

Google ... how much energy does the earth receive from the sun

A total of 173,000 terawatts (trillions of watts) of solar energy strikes the Earth continuously. That's more than 10,000 times the world's total energy use. And that energy is completely renewable — at least, for the lifetime of the sun.Oct 26, 2011
Shining brightly | MIT News | Massachusetts Institute of ...https://news.mit.edu › energy-scale-part3-1026

It seems to me the human race is in the midst of a torrent of available energy, more than sufficient to meet every conceivable need for every conceivable purpose, but only a tiny fraction of the population have the dimmest understanding of how to go about meeting the totality of the need.

This forum ** may ** contain members who can look at the big picture (on behalf of the population) and see ways of proceeding that will result in elimination of energy poverty.l

(th)

SpaceNut · 2021-06-19 18:38:26

2/3 rds of the earth is oceans so what manned presence in them is small so we get the surplus from not occupying that footage as the ocean are absorbing that energy and man is not capturing any of it. course with each passing hour the amount of land versus ocean is changing for the rate of absorption.

I believe that total number is against a 24 hr clock assuming compensation for the change with latitude and longitude figured in as the hour window of high noon is the max solar amount as every thing on either side of that is a value that is less.

https://unboundsolar.com/solar-informat … calculator

hourly state table given

Average peak sun hours by state
Location Peak Sun Hours (PSH)
Alabama 3.5 – 4
Alaska 2 – 3
Arizona 7 – 8
Arkansas 3.5 – 4
California 5 - 7.5
Colorado 5 – 6.5
Connecticut 3
Florida 4
Georgia 4 – 4.5
Idaho 4 – 4.5
Illinois 3 – 4
Indiana 2.5 – 4
Iowa 4
Kansas 4 – 5.5
Kentucky 3 – 4
Louisiana 4 – 4.5
Maine 3 – 3.5
Maryland 3 – 4
Massachusetts 3
Michigan 2.5 – 3.5
Minnesota 4
Mississippi 4 – 4.5
Missouri 4 – 4.5
Montana 4 – 5
Nebraska 4.5 – 5
Nevada 6 – 7.5
New Hampshire 3 – 3.5
New Jersey 3.5 – 4
New Mexico 6 – 7
New York 3 – 3.5
North Carolina 4 – 4.5
North Dakota 4 – 4.5
Ohio 2.5 – 3.5
Oklahoma 4.5 – 5.5
Oregon 3 – 5
Pennsylvania 3
Rhode Island 3.5
South Carolina 4 – 4.5
South Dakota 4.5 – 5
Tennessee 4
Texas 4.5 – 6
Utah 6 – 7
Vermont 3 – 3.5
Virginia 3.5 – 4
Washington 2.5 – 5
West Virginia 3
Wisconsin 3.5
Wyoming 5.5 – 6

louis · 2021-06-19 18:46:04

That's just the Earth. If you think in terms of PV satellites it will be vastly more as you go into outer Earth orbit.

I am absolutely confident that in the next 100 years we will find ways of capturing that vast flow of energy and be able to beam it back to Earth.

However, until that technology becomes mature, back on our planet we can improve PV technology in numerous way and also develop energy storage technology. I think we can't be more than 20 years away from viable PV plus storage energy systems that meet all our needs - and very cheaply as well.

tahanson43206 wrote:

The human race is (hopefully) very early in its development.
At present, some members of the population perceive a poverty of energy, and claim that whatever energy is available is being consumed faster than it is being captured.
I was curious to see if Google might be able to provide some facts to work with.

Inquiry regarding energy passing Earth

Google ... how much energy does the sun produce?
About 337,000,000 results (0.83 seconds)
The sun releases energy at a mass–energy conversion rate of 4.26 million metric tons per second, which produces the equivalent of 384.6 septillion watts (3.846×1026 W).Dec 14, 2015
How does the sun produce energy? - Phys.org

Google ... how much energy does the earth receive from the sun
A total of 173,000 terawatts (trillions of watts) of solar energy strikes the Earth continuously. That's more than 10,000 times the world's total energy use. And that energy is completely renewable — at least, for the lifetime of the sun.Oct 26, 2011
Shining brightly | MIT News | Massachusetts Institute of ...https://news.mit.edu › energy-scale-part3-1026

It seems to me the human race is in the midst of a torrent of available energy, more than sufficient to meet every conceivable need for every conceivable purpose, but only a tiny fraction of the population have the dimmest understanding of how to go about meeting the totality of the need.
This forum ** may ** contain members who can look at the big picture (on behalf of the population) and see ways of proceeding that will result in elimination of energy poverty.l
(th)

Last edited by louis (2021-06-19 19:24:33)

SpaceNut · 2021-06-19 18:53:40

orbital solar is higher but you are constantly trying to aim the panels while zipping around which means you are not getting all of the energy when collected to beam to earth....
1300 watts in space versus the 1100 on earths surface... with the same panels now seeing high levels of heat which drops the effectiveness of the energy captured.

tahanson43206 · 2021-06-19 19:07:06

For Louis and SpaceNut ... thank you ** both ** for giving this new topic a rolling start!

SpaceNut .... may I give you a homework assignment ????

Can you research and report on how NASA deals with the intake of energy by solar panels in space.

The issues you raised sound important (to me for sure) and worth our understanding.

Also for SpaceNut .... For many years, Earthly intelligence agencies, and lately commercial data suppliers, have (apparently) solved the problem of how to keep a camera pointed precisely at a location on the surface of the Earth while moving in X, Y and Z at significant velocity.

It would be helpful to know how that is done, so that solar energy supply systems can be designed to perform as well as the optical ones.

***
For all ... where I would like to go with this new topic is toward a collective understanding of how MUCH energy is available to be harvested from the massive flow from the Sun, and a few of the ways to increase the amount we are presently collecting.

There is ** another ** issue to address ...

I saw a report recently indicating the the Earth Energy Budget is out of balance. Apparently, the Earth is taking in more energy from the Sun than it is radiating to Space. The net effect is accumulation of thermal energy in the Earth. This is not the same thing as causing heating of the Earth due to contamination of the atmosphere with gases that should not be there, although the two may be related.

(th)

louis · 2021-06-19 19:26:50

I was simply referencing the fact that with orbiting satellites - as far out as 10s of thousands of miles, the area of insolation you can draw on is much greater than just the Earth surface.

SpaceNut wrote:

orbital solar is higher but you are constantly trying to aim the panels while zipping around which means you are not getting all of the energy when collected to beam to earth....
1300 watts in space versus the 1100 on earths surface... with the same panels now seeing high levels of heat which drops the effectiveness of the energy captured.

louis · 2021-06-19 19:31:52

This isn't something I've researched but if, for your orbiting satellite, you have a cylinder surfaced with PV panels (with the cylinder perpendicular to the orbital plane) then it will be picking up PV power at all times until it is behind the Earth. My intuition says if it is say 36 K miles out in orbit it will be getting maximum insolation probably 80% of the time. Happy to see what others think.

tahanson43206 wrote:

For Louis and SpaceNut ... thank you ** both ** for giving this new topic a rolling start!
SpaceNut .... may I give you a homework assignment ????
Can you research and report on how NASA deals with the intake of energy by solar panels in space.
The issues you raised sound important (to me for sure) and worth our understanding.
Also for SpaceNut .... For many years, Earthly intelligence agencies, and lately commercial data suppliers, have (apparently) solved the problem of how to keep a camera pointed precisely at a location on the surface of the Earth while moving in X, Y and Z at significant velocity.
It would be helpful to know how that is done, so that solar energy supply systems can be designed to perform as well as the optical ones.
***
For all ... where I would like to go with this new topic is toward a collective understanding of how MUCH energy is available to be harvested from the massive flow from the Sun, and a few of the ways to increase the amount we are presently collecting.
There is ** another ** issue to address ...
I saw a report recently indicating the the Earth Energy Budget is out of balance. Apparently, the Earth is taking in more energy from the Sun than it is radiating to Space. The net effect is accumulation of thermal energy in the Earth. This is not the same thing as causing heating of the Earth due to contamination of the atmosphere with gases that should not be there, although the two may be related.
(th)

Last edited by louis (2021-06-19 19:32:39)

SpaceNut · 2021-06-19 19:44:27

Using a targeting alignment system that picks up a given star to lock on.
everything else is moving relative to that fixed point.

To make the system simpler use the Lagrange points so as to keep from the need to be orbiting the earth so fast and can be more stationary pointing at a target in the polar region of earth for the systems beam.
The collector would want to be high in the atmosphere and have a cable passing the power to the world below.

tahanson43206 · 2021-06-19 20:09:54

For Louis (in particular because your post mentions being out of sunlight) ...

This subject has been presented in the forum previously, so i won't repeat it here except to invite a search if anyone is interested ... There is a class of orbits (a subset of polar orbits) that are designed to stay in the sunlight all the time. The orbits are designed to precess at exactly the correct rate so that they remain in the dusk/morning boundary (from the Earth perspective). Thus, they are NEVER in shadow.

The elevation is in need of clarification for the purposes of solar power capture and delivery. The primary purpose of these satellites (those in use today) is for Earth observation, when the need is to NEVER loose a moment due to the Earth being in shadow. From what I've been able to discover so far, this is a well proven and well established subset of polar orbits.

For purposes of capture of solar energy, the point raised by SpaceNut is important. The satellites are in orbit around the Earth, and the Earth is turning under the satellites (which are ALWAYS in the same plane with respect to the Sun), so the antenna pointing capability needs to be very good indeed.

However, happily, it appears that electronic beam steering has been developing over recent decades, so that there is a chance electronic steering can be used to deliver power beams to on-Earth receiving stations.

The Sun-Synchronous polar orbits for these salellites would permit transmission distances on the order of hundreds of miles (or kilometers) instead of many thousands which are needed for Geosynchronous orbits. Therefore, the loss of signal strength due to dispersion of radio waves would be dramatically less.

For SpaceNut ... most designs for rectenna farms anticipate they will be mounted just above the surface of the Earth, with grass or other crops underneath. The rectenna farms need to be in fixed positions and close to conduits for delivery to energy storage facilities.

(th)

SpaceNut · 2021-06-20 19:02:53

https://en.wikipedia.org/wiki/Rectenna

Antenna design
https://www.miklor.com/COM/pdf/PracAntDesignVHF.pdf

https://its-wiki.no/images/8/80/Antenna_Design.pdf

Microwave Beamed power
https://ntrs.nasa.gov/api/citations/198 … 018286.pdf

https://www.newswars.com/us-military-pl … -to-earth/

https://www.moonsociety.org/projects/po … g-project/

As seen in the wiki article a fabric based design of a ballon shell can be used to get the antenna high above earth so that the beam can not be where people might be.

Then re-beam to a tighter radius beam to a much small target below the balloon...

tahanson43206 · 2021-06-20 19:32:23

For SpaceNut re #10

The links you provided are chock full of good information ... I note the NASA publication is referenced by the Wiki article (or at least Dr. Brown is referenced) I appreciated the updates in the Wiki article about progress in the direct conversion of optical wavelength photons to direct current.

https://en.wikipedia.org/wiki/Rectenna

Optical rectennas
Main article: Optical rectenna
In principle, similar devices, scaled down to the proportions used in nanotechnology, can be used to convert light directly into electricity. This type of device is called an optical rectenna (or "nantenna").[9][10] Theoretically, high efficiencies can be maintained as the device shrinks, but to date efficiency has been limited, and so far there has not been convincing evidence that rectification has been achieved at optical frequencies. The University of Missouri previously reported on work to develop low-cost, high-efficiency optical-frequency rectennas.[11] Other prototype devices were investigated in a collaboration between the University of Connecticut and Penn State Altoona using a grant from the National Science Foundation.[12] With the use of atomic layer deposition it has been suggested that conversion efficiencies of solar energy to electricity higher than 70% could eventually be achieved.
The creation of successful optical rectenna technology has two major complicating factors:
Fabricating an antenna small enough to couple optical wavelengths.
Creating an ultra-fast diode capable of rectifying the high frequency oscillations, at frequency of ~500 THz.
Below are a few examples of potential paths to creating diodes that would be fast enough to rectify optical and near-optical radiation.
Geometric Diodes
A promising path towards creating these ultrafast diodes has been in the form of "geometric diodes".[13] Graphene geometric diodes have been reported to rectify terahertz radiation.[14] In April 2020 geometric diodes were reported in silicon nanowires.[15] The wires were shown experimentally to rectify up to 40 GHz, but that was instrument limited, and theoretically may be able to rectify signals in the THz region as well.

This progress is certainly encouraging. The ideal would be an all-electronic system in orbit.

The Wiki article discusses cascading losses at each stage of the process.

The balloon idea would represent an additional set of losses, because the signals from space would have to be converted to DC and then reconverted to RF for the final stage of transmission.

The fewer stages there are in the system, the better.

(th)

SpaceNut · 2021-06-20 20:00:37

True under normal consideration but from solar any energy is a prize

https://pdfs.semanticscholar.org/789d/a … 5470f5.pdf

The transmitted radio frequency (RF) power can reach a level of microwatts (W) to milliwatts (mW) DC, which is a useful range for charging batteries or powering battery-free devices. The main challenge of RF energy transmission is the low level of the received power and the RF-DC power conversion efﬁciency (PCE).

https://circuitdigest.com/article/rf-en … cal-energy

https://www.allaboutcircuits.com/techni … -hardware/

kbd512 · 2021-06-21 00:08:29

At 170GHz to 300GHz, the Earth's atmosphere, even when loaded with water vapor, is very nearly transparent up to something on the order of 100 miles or thereabouts. Both electronics and structures do not like being constantly heated and cooled in an extreme fashion, so if PV arrays could be positioned in polar orbits such that they always remain in sunlight, thus at a constant 250F, then despite the fact that some active cooling will be required for certain components, this would be much better for cell life than continuously heating and cooling. The radiation environment would take its own toll on the equipment, as would SPEs / CMEs, but in normal operations the service life of the PV cells should be improved.

If Starship can make launches cheap enough, or we develop electromagnetic launch systems (28kWh/kg to LEO), or beamed microwave power for orbital launches (Hydrogen monopropellant rockets with 1,000s of specific impulse), or a SSTO such as the British Skylon, that significantly reduces propellant consumption and launch costs (assuming all are equally reliable and durable in operation, which is almost never true for an operational system), then we could feasibly do solar power satellites.

In terms of propellant to payload ratio, Starship is 36:1, Skylon is 17:1, beamed microwave power with 1,000s Isp is approximately 6:1 (KSC to a 185km circular orbit, with 2,000kN of thrust), and at least in theory, an electromagnetic launch would only require enough propellant to circularize the orbit, although practical limitations (such as killing people with pressure waves) would likely preclude electromagnetic launch from doing much more than accelerating the launch vehicle to high subsonic speeds. It should be abundantly clear that start with 1,000s of specific impulse (zapping Hydrogen with a microwave beam) roughly triples the economy of energy usage over a LOX/LH2 SSTO, and is an improvement over LOX/LCH4 by a factor of 6. The combination of electromagnetic launch to high subsonic speed with LH2-only SSTO using beamed microwave power would further decrease the amount of fuel required, but mostly it would ensure that the vehicle is already moving well beyond flying speed prior to leaving the ground, so a launch abort becomes much more feasible to do.

Ground-based rectennas would be vastly cheaper to build and maintain than over-capacity PV systems that require burdensome changes to power distribution infrastructure, as a function of the low capacity factor of PV. That otherwise intractable problem forces utilities to construct 2 or 3 complete power plants to contend with the fact that ground-based PV is hamstrung by basic physics (diurnal cycles, clouds, severe weather, seasonality). If we have full Sun 24/7, then we don't have grid capacity and storage problems to solve.

Incidentally, back in 2020 the US Navy launched a power beaming satellite experiment aboard the USAF's X-37B, so beamed solar power is definitely on DoD's radar screen. They're conducting endurance testing of the equipment to see how well suited it is for the environment.

Calliban · 2021-06-21 05:15:10

Kbd512, excellent post. Launch assist techniques have been discussed as some length on this board before. One of the most interesting revelations for me was the discovery that a very large proportion of the fuel mass carried by the space shuttle was consumed overcoming gravity losses in the first minute after takeoff, whilst accelerating to a speed of just 1000mph. A while back I can remember Musk stating that his Starship upper stage could reach orbit as an SSTO, but would carry virtually no payload in doing so. A short term goal for reducing launch costs would be to eliminate the need for a Starship lower stage, by accelerating the upper stage using a launch assist. This would eliminate about two thirds of takeoff mass and presumably cut capital cost by a similar amount. The question is, can a launch assist provide sufficient velocity boost to eliminate the need for a lower stage?

Regarding a rectenna, my understanding is that this is essentially a net of wires. So I would agree that it is a much lower cost piece of infrastructure than a PV array of similar size. I don't think an SPS needs to be in a permanently illuminated polar orbit. In a geostationary orbit, it is in sunlight for 95% of the time. It will pass into shadow and lose power for one hour each day at entirely predictable times. We deal with predictable, short outages like that, using open cycle gas turbines, pumped storage, compressed air, flywheels, battery banks, etc. Small amounts of energy storage for predictable periods are affordable and likely to be easier than attempting to steer the microwave beam to different ground based targets as the satellite orbit carries it over different parts of the Earth surface.

Last edited by Calliban (2021-06-21 05:30:25)

tahanson43206 · 2021-06-21 05:21:56

For kbd512 re #13

Thank you for your substantial support of the polar orbiting SPS concept!

The potential power delivery from the dawn/dusk orbital band extends from (about 100 miles) to as far out as the equipment can deliver power to the ground.

The ** big ** worry that I have right now is the Kessler Syndrome potential of a large number of ** very LARGE ** satellites crossing the paths of thousands and thousands of Internet communications satellites that are in a great variety of orbits, along with all the other satellites in their random orbits.

The need for global traffic management is already clear, but it is becoming more evident every day.

In the early days of air travel, regulation and coordination of movements was not necessary, but as time went on the need for coordination of landings in particular, but for movements in particular became clear, and humans managed to organize themselves so that we now have robust conventions that everyone follow to insure safe travel for everyone.

We need something like that for space travel in the vicinity of a planet, and we need it sooner rather than later.

I am hoping someone currently active in the forum might be able to spend some time calculating the power gathering potential of the dawn/dusk band around the Earth.

I am hoping to learn it is sufficient to provide clean power in the quantities needed to sustain civilization on Earth as fossil fuels phase out.

I'm about to drop off a post about the inevitable carbon increase caused by the (to my mind less than sensible) shuttering of nuclear power plants around the world.

Thanks again for your contribution!

Edit: As a reminder, there is an extensive exploration of this concept earlier in the archives.

A key concept available for study in the earlier work is the fact that power is available twice a day to every location on Earth that needs it.

The satellites themselves deliver power continuously to locations on the Earth, by shifting the power beam instantaneously from one rectenna farm to the next as appropriate. This means (of course) that each rectenna farm will be fitted with storage capacity for 12 hours of delivery to customers.

Power is thus available twice a day 365 days a year without significant degradation due to atmospheric conditions at a particular rectenna site.

Rectenna sites far from human habitation can produce useful products that require investment of energy, including fuels of various kinds but including all materials that require investment of energy for refinement and shaping for use.

(th)

kbd512 · 2021-06-21 06:19:33

Calliban,

The use of polar orbits was related to avoiding that 500 degree temperature swing, which does a number on all electrical and structural components. If we have components that are truly capable of withstanding the temperature delta over 25 years, then yes, a geosynchronous orbit is a much better option from an operations standpoint. This is likely an area where we have to compromise for sake of simplicity in operation.

tahanson43206 · 2021-06-21 06:36:45

For Calliban re #14

Thank you for adding a reminder of the potential of geosynchronous orbit.

SPS have been proposed for geosynchronous orbit. There was quite a bit of work done (and books and papers published), but after (by now) many decades, no such power facility exists.

Perhaps some day we will see SPS in service.

The distinct advantage of a dawn/dusk polar orbit for SPS is the proximity to the rectenna installation.

The distinct (and significant) disadvantage is the movement of the SPS with respect to the customer site.

however, there ** is ** another ** very ** significant advantage.

By definition, a geosynchronous SPS will be limited in reach to the cone of the Earth that it can "see".

The dawn/dusk polar orbit systems will cover ** every ** square meter of the Earth twice an (Earth) day.

Rectenna can be deployed at the poles and in the ocean island locations, and even in floating factory locations.

(th)

kbd512 · 2021-06-21 11:41:11

For those who are curious, microwave power transmission at 170GHz+ is up to 80% efficient for gyrotrons from 1MW to 10MW output RF power. This is commercial technology developed for the international nuclear fusion program. For whatever reason, weight is also a factor for these units, so they've become increasingly lighter and more compact over the years, with great attention paid to stable output and proper cooling for continuous operation.

Let's say you get 24kWh/m^2 on Earth or in orbit, but rotation of the Earth and weather limit the ground based installation to a maximum of 20% of the daily insolation. That equates to 4.8kWh. Let's say you get 95% of that from orbit because you're seldom in Earth's shadow, and of that 95%, you ultimately capture, transmit, and convert 70% of that power. That equates to 15.96kWh, a far cry from the 4.8kWh you would've collected from a panel fixed to Mother Earth, and since that power output is nearly continuous, storage becomes superfluous. Power generation trumps power storage every day of the week. The solution to that "lost power" from transmission and conversion, is merely to "build it bigger". Heck, even if you ultimately lose 50%, you still come out on top in an unambiguous way. Your panels are never subjected to storm damage or dust accumulation, either, so continuous output is all but guaranteed. So long as emergency gas turbine generators are present on the ground, any unforeseen emergencies are covered by a backup solution. The ability to beam power to areas affected by natural disasters, so that damaged grid infrastructure can be electrically bypassed, is another built-in resiliency feature.

Beyond the most obvious use case, beamed power makes it feasible to remotely power ships and airliners, especially flying boats that can land on the ocean in the event of power loss. If the US Navy had gigantic remotely powered flying boats acting as airborne aircraft carriers, then it's technologically feasible to deliver troops and aircraft to flashpoints in the Pacific in mere hours, rather than days to weeks. This would greatly reduce or possibly eliminate, in some cases, the need to forward deploy our ships from naval bases in foreign countries. We wouldn't need nuclear powered super carriers or even diesel / gas turbine powered amphibious carriers, given the ability to deploy troops and micro fighters in 12 hours or so, from Hawaii to Japan. Since the US Navy is clearly interested in using beamed power, this is an obvious first application of the technology.

tahanson43206 · 2021-06-21 12:47:22

For kbd512 re #18

Thanks for the numbers you provided for a comparison of on-orbit and on-ground solar power installations.

***
For all ... this is a todo item that the more mathematically inclined members might find interesting ... at least i hope so ...

The Dawn/Dusk concept amounts to a cylinder of energy flowing past the Earth from elevation of (about) 100 miles to Geosynchronous orbit ...

I'd be interested to see how much energy is potentially available in a cylinder from 100 miles (162 km) inside diameter out to 1000 miles (1620 km).

At this point I have no sense of the magnitude of the available energy compared to the need on Earth.

Something to consider is that while the Sun delivers water for free from the oceans to various locations on the Earth, it does so in a random manner.

The ideal circumstance would be for the Solar energy needed to harvest water to be harnessed to deliver fresh water to where it is needed on land.

Is there enough energy in the band around Earth to provide fresh water where it is needed, in addition to supplying all the existing energy requirements for the existing human civilization?

I have no idea. All I know for CERTAIN is that ** every ** molecule of water that moves around the Earth with the wind is placed there by individual photons provided by the Sun.

And fresh water supply for entire Earth is just ** one ** of the services performed by the totally free energy supply we enjoy, thanks to being in the vicinity of the Sun.
(th)

tahanson43206 · 2021-06-21 13:52:07

This post is about defensive measures for a solar power satellite in low Earth orbit in a dawn/dusk polar orbit ....

The solar panels for such a satellite would be as large as a US football field at a minimum, and probably larger.

To protect such solar panels from collisions with objects in low Earth orbit that are travelling across the path of the polar satellites, it would be possible to arrange for the panels to rotate around an axis that is itself aligned with the direction of travel. The mass of the solar panels would be equally balanced between the down-orbit panels and the up-orbit ones, so that by rotating the panels in opposite directions, momentum is preserved and the stability of the system is preserved. After the danger is past, the panels would be rotated back into full sun-facing aspect.

The radio frequency array would itself be parallel to the ground and thus not at risk, although the cross section of the satellite would present a strike surface in any case.

(th)

SpaceNut · 2021-06-21 17:04:00

All forms of energy fan out from the transmitting source and become weaker as distance.
LEDs measure that fan out angle at a fixed distance when taking power measurements.
RF transmitted energy can overwhelm objects with in the beam directional path.

tahanson43206 · 2021-06-21 18:06:53

For SpaceNut re #21

Thank you for reminder of factors that must be taken into account when designing a high power remote power transmission system.

Here is a web site Google came up with when I asked about divergence ...

https://www.laserworld.com/en/laserworl … lator.html

While the web site is (apparently) devoted to study of laser beams, I thought the statement made about aperture size might be helpful in planning a transmitter to deliver power over 1000 miles (1620 km).

It should be possible to calculate the amount of divergence to be expected at a particular frequency, and plan to extend the rectenna field to catch the outer rings of energy that would be present.

Edit#1 (next day) .... your observation about the RF potentially having an effect upon satellites, aircraft or birds moving through the beam stayed with me.

For orbiting objects the transit time would be (relatively) short ... satellites in the non-polar orbits are going to be traveling at 17,000 mph (28,000 kph) while the power satellites will be traveling in the dawn/dusk polar orbits at some lesser velocity due to increased altitude. If a beam is the size of an American football field, then it will be (on the order of) 100 meters in diameter. The transit time for a satellite passing through the beam would be:

7.8 km / second >> 7800 meters / second >> for 100 meters so the 78th part of a second >> (on the order of) 13 milliseconds

The transit time for an aircraft would be greater, depending upon the velocity of the aircraft.

On the ** other ** hand, the times when beams would be present would be knowable, since the satellites would always be in the dawn/dusk band.

The transit time for a bird would be greater still, so I would expect some effect, which should be predictable. It is possible studies have been done on the effect of microwaves on animals (including humans) since top tier nations have been deploying powerful radar installations for many decades.

SearchTerm:animals effect of RF bean on

(th)

SpaceNut · 2021-06-22 17:10:57

Solar power investors burnt by rise in raw materials costs

The rapid rise in prices for raw materials has reversed a decades-long decline in the cost of solar energy, companies face higher steel, polysilicon and freight costs. The supply chain pressures are limiting the potential for further reductions in the costs of solar installations, just as governments pledge to focus on a “green recovery” from the pandemic.

tahanson43206 · 2021-06-24 10:09:41

This post is offered in hopes a registered member with posting privileges will find it interesting enough to pursue for the record....

Premise: There is a band of energy flowing past the Earth that could be captured and made available for use on Earth

The band of interest (to me for this post) is from about 100 miles (162 km) above the surface, to about 1000 miles (1620 km).

This band has an area which is knowable.

The energy flowing past each square segment of this band is knowable.

The total energy available is knowable.

The total energy consumed by human beings on Earth can only be estimated, but estimates of varying quality are available.

I expect to learn that the amount of energy flowing uselessly past the Earth, in the band of interest, is far in excess of whatever the current energy consumption may be observed on Earth, using fossil fuels as the resource, but including all sources of energy.

Harvesting the energy in the band of interest would require a collective effort of which the human race is not currently capable.

However, the threats facing the human race are of sufficient magnitude so that some small percentage of the population may be motivated to try to organize the population to meet the threats.

Halting efforts along those lines are reported in the media from time to time.

(th)

SpaceNut · 2021-06-24 19:11:02

Keeping anything above earth means we need to be beyond the drag of the earth atmosphere to which even the ISS is considered LEO and must get re-boosted to be able to stay in place. That said we know that we are closer to the 1,000 mile value.

The international space station orbits the earth at an average distance of approximately 248 miles (400 kilometers)”. Whereas the minimum possible ISS approximate distance is 330 km (205 mi) and a maximum of 410 km (255 mi) from the earth’s surface.

That said we have a known location to test equipment that could be used to try any means to collect the energy other than a solar panel....

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#1 2021-06-19 18:27:49

Energy Supply in Solar System vs Productive Use

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