Creating engry in space.

[MeteorWayne]

If there's energy absorbed by the "front" turbine, there's none left over to make the "rear" spin in the opposite direction.

 

[Jimmyboy]

If there's energy absorbed by the "front" turbine, there's none left over to make the "rear" spin in the opposite direction.

I thought it would have worked, but i'm not an astrophysicist.

Out of curiosity MW why wouldnt the back propeller have any energy to spin? or at least let the front propeller spin?

 

[MeteorWayne]

If the front turbine captures all the energy, none makes it to the back turbine to make it spin in the opposite direction. Hence, the whole assembly spins in the direction of the front turbine, so there's no rotation relative to the generator, since it's spinning at the same speed as the front turbine.

 

[undidly]

Again, what holds the outer part still so the spining creates work? In space, as the turbine spins, so does the turbine holder and generator so there is no net motion to create electricity. To hold the genberator in place, you need to supply as much energy as the turbine creates!

I already explained these things.

The outer part has two counter rotating turbines .Torque adds to zero.
The outer part (main structure ) could alternately have a torque arm with a sail at the end to provide a counter torque.

No energy is needed to hold something in place.

""To hold the genberator in place""
Do you mean its orbital position?.
Tilting the turbines to reflect some light at an angle can drive the whole thing in any required direction.

 

[MeteorWayne]

Again, what holds the outer part still so the spining creates work? In space, as the turbine spins, so does the turbine holder and generator so there is no net motion to create electricity. To hold the genberator in place, you need to supply as much energy as the turbine creates!

No energy is needed to hold something in place.

That's just a silly statement.

""To hold the genberator in place""
Do you mean its orbital position?.
Tilting the turbines to reflect some light at an angle can drive the whole thing in any required direction.

No, I mean what hold the body of the structure of the turbine assembly in place so it doesn't rotate with the turbine itself.

Your "flag" idea above might be the right idea...it would just have to be a larger turbine outside the inner one...but in any case, it will all flow downstream, and energy will be required to hold it in place so energy can be extracted.

 

[Jimmyboy]

If the front turbine captures all the energy, none makes it to the back turbine to make it spin in the opposite direction. Hence, the whole assembly spins in the direction of the front turbine, so there's no rotation relative to the generator, since it's spinning at the same speed as the front turbine.

I did say MW that you could adjust the front propellers area (make it smaller) so the rear one receives the same amount of engergy as the front.

You could have it tetherd to a orbiting meteor or moon or something like that, in which case it is just a windmill..

 

[undidly]

If the front turbine captures all the energy, none makes it to the back turbine to make it spin in the opposite direction. Hence, the whole assembly spins in the direction of the front turbine, so there's no rotation relative to the generator, since it's spinning at the same speed as the front turbine.

I did say MW that you could adjust the front propellers area (make it smaller) so the rear one receives the same amount of engergy as the front.

You could have it tetherd to a orbiting meteor or moon or something like that, in which case it is just a windmill..

The rotors can be side by side.
See chinook helicopter.

 

[undidly]

Again, what holds the outer part still so the spining creates work? In space, as the turbine spins, so does the turbine holder and generator so there is no net motion to create electricity. To hold the genberator in place, you need to supply as much energy as the turbine creates!

No energy is needed to hold something in place.

That's just a silly statement.

""To hold the genberator in place""
Do you mean its orbital position?.
Tilting the turbines to reflect some light at an angle can drive the whole thing in any required direction.

No, I mean what hold the body of the structure of the turbine assembly in place so it doesn't rotate with the turbine itself.

Your "flag" idea above might be the right idea...it would just have to be a larger turbine outside the inner one...but in any case, it will all flow downstream, and energy will be required to hold it in place so energy can be extracted.

ME ""No energy is needed to hold something in place.""

YOU ""That's just a silly statement.""

Where does the energy come from to hold the moon in place?.

 

[MeteorWayne]

The moon is in orbit around the earth-moon barycenter. It is so massive, that the solar forces (wind and radiation) are insignificant. That would not the the case with a small, light turbine assembly designed to capture that energy, unless you intend to make it as massive as the moon. See? Silly.

 

[undidly]

The moon is in orbit around the earth-moon barycenter. It is so massive, that the solar forces (wind and radiation) are insignificant. That would not the the case with a small, light turbine assembly designed to capture that energy, unless you intend to make it as massive as the moon. See? Silly.

You seem to be suggesting that the wind and radiation forces are strong enough to push the assembly away from the sun.
If this should happen then it can be brought nearer to the sun by turning the turbines on edge so they intercept very
little light.
A properly designed system would have the forces and gravitational attraction to the sun in balance.
They would remain in balance at any distance as they both follow the inverse square math.
Tilting the turbines or adding a solar sail can correct any error in position.

 

[jakeyboi]

What do you want the energy for? if its floating around in space how will transfer that energy back to earth or to a spaceship?

How about some mirrors like those on the james webb telescope that could be directed at turbines on earth or solar panels on a space craft?

 

[undidly]

What do you want the energy for? if its floating around in space how will transfer that energy back to earth or to a spaceship?

How about some mirrors like those on the james webb telescope that could be directed at turbines on earth or solar panels on a space craft?

"" or to a spaceship?""

It IS a space ship.
The turbines are mounted on a spaceship.

"" transfer that energy back to earth? ""
Too much trouble.Use the energy on the spaceship.
Earth gets 1000 Watts sunlight per square meter at midday.
That greedy Earth people can manage on that.

Solar cells and Stirling engines can produce more output but wear out in 20 years.
Light turbines last as long as the control electronics.
A passive turbine control system and gravity gradient orientation (to the Sun) could operate unattended for a million years.

 

[theridane]

Light turbines last as long as the control electronics.
A passive turbine control system and gravity gradient orientation (to the Sun) could operate unattended for a million years.

Yea beacuse we've never seen a micro meteor hit a spacecraft, a tether, or a multi-milion-square-meter tinfoil solar turbine.

 

[undidly]

Light turbines last as long as the control electronics.
A passive turbine control system and gravity gradient orientation (to the Sun) could operate unattended for a million years.

Yea beacuse we've never seen a micro meteor hit a spacecraft, a tether, or a multi-milion-square-meter tinfoil solar turbine.

I never said anything about a"" multi-milion-square-meter tinfoil solar turbine""

I intended smaller but rapidly rotating turbines ,1 meter radius spinning at 100,000 rpm for example.
A even number of turbines , half spinning in each direction to cancel any overall torque.
A large mirror behind the turbines would reflect light onto the back to drive them from both sides and give protection from micro meteorites approaching from behind .Most meteorites come from that direction.The suns gravity captures those from the front.
Angled mirrors at the sides give even more light and also side protection.
I think I have solved all the problems.

 

[theridane]

It doesn't matter if it's a single giant windmill or a buttload of little ones, one way or another you still need to cover an insane surface area on the order of square kilometers to do the same deal of work a square meter solar panel does.

So now we're adding mirrors to the mix? How much is that in terms of weight... another dozen Atlas V Heavies? And besides, mirrors aren't exactly the kind of meteor protection I'd like to see around me. Even if you coated the whole thing with Whipple shields it would still look like swiss cheese before it even managed to spin up and produce some measurable shaft power.

We already have spacecraft in orbit, many of them. They all have surface areas in dozens of square meters. They spend most of their time in direct sunlight. Yet the effects of solar pressure are so minuscule that they only manifest themselves as longer-term orbital perturbations. Not one of them is spinning up like a turbine. A Soyuz doesn't get pulled away from the ISS when coasting in for a dock. Why is that?

 

[undidly]

It doesn't matter if it's a single giant windmill or a buttload of little ones, one way or another you still need to cover an insane surface area on the order of square kilometers to do the same deal of work a square meter solar panel does.

So now we're adding mirrors to the mix? How much is that in terms of weight... another dozen Atlas V Heavies? And besides, mirrors aren't exactly the kind of meteor protection I'd like to see around me. Even if you coated the whole thing with Whipple shields it would still look like swiss cheese before it even managed to spin up and produce some measurable shaft power.

We already have spacecraft in orbit, many of them. They all have surface areas in dozens of square meters. They spend most of their time in direct sunlight. Yet the effects of solar pressure are so minuscule that they only manifest themselves as longer-term orbital perturbations. Not one of them is spinning up like a turbine. A Soyuz doesn't get pulled away from the ISS when coasting in for a dock. Why is that?

http://mashable.com/2010/04/28/solar-spaceship/

""it would still look like swiss cheese before it even managed to spin up and produce some measurable shaft power.""

 

[theridane]

• That's a 20-meter sail travelling in the interplanetary void, compare with a several kilometer-wide windmill battery in Earth orbit in terms of impact collection.
• Even they are expecting it to last at most two years, even in the void it heads into.
• The mission hasn't even really started yet, the sail is yet to deploy, who knows what happens next.
• This small, fast and agile sail is expected to perform a solar-powered rotational maneuver of a single revolution in more than a day, and that's only because it's completely free, not attached to a generator or anything.
• Are you serious or am I missing some kind of a cultural reference, joke or pun?

 

[undidly]

• That's a 20-meter sail travelling in the interplanetary void, compare with a several kilometer-wide windmill battery in Earth orbit in terms of impact collection.
• Even they are expecting it to last at most two years, even in the void it heads into.
• The mission hasn't even really started yet, the sail is yet to deploy, who knows what happens next.
• This small, fast and agile sail is expected to perform a solar-powered rotational maneuver of a single revolution in more than a day, and that's only because it's completely free, not attached to a generator or anything.
• Are you serious or am I missing some kind of a cultural reference, joke or pun?

I am serious.
I was thinking interplanetary void ,other side of the sun ,over a pole of the sun.
Two years survival for very thin foil.
So make the turbine from thicker metal.
The output depends on the light intensity and spin speed so spin up a strongly built turbine by some other means.
At full speed it gives full output no matter how heavy is the turbine.

Rotational movement ?.
The sail has no twist.
Left right up down I can understand,but rotate?.

 

[jakeyboi]

i think you've got to give up on the solar turbine idea. Stick with the duracells!!!

 

[neilsox]

Re: Creating energy in space.

On SBSP/SSP/SPS, GEO stationary orbit will likely be best when we have a million megawatts of SBSP. In the meantime, solar synchronous semi polar orbit has numerous advantages. Even far Northern countries can receive the beam during, and a few hours before, the evening peak demand period. With rare exceptions they won’t pay more than 4 cents per kilowatt hour for electricity at other times of day as their own generators are adequate, and not practical to shut down for a few hours. Other advantages are international companies and/or governments can share the start up costs, ship propulsion and the SPS is considerably closer than GEO but still in continuous sunlight. GEO satellite owners will be unhappy about megawatts, being transmitted near by.
Economies of scale likely run out at less than 100 megawatts, making many SPS practical. This is because 100,000 volts dc at 100 amps = 10 megawatts. More volts or more amps creates rapidly rising costs in space, so logically we build many medium size SPS. The Sun delivers about 1300 watts per square meter, but following the numerous conversions, and losses perhaps only 130 watts per square meter is delivered to the grid. Thus one square kilometer of solar panel in space, puts 130,000,000 watts = 130,000 kilowatts = 130 megawatts on the grid. That may be a billion solar cells in series parallel. That many connections presents a reliability problem, especially for open cells which are likely to reach temperatures of thousands of degrees as the very high voltage arcs across the open circuit. Solutions, especially at one million volts, get very complicated, heavy and expensive.
Almost a million laser diodes connected in series to use the million volts DC produce similar potential arcing which will damage nearby diodes.
Laser diodes are superior as they can focus on to existing solar farms (or ships at sea) with dimensions as small as 60 meters by 100 meters = about 5000 square meters = one megawatt if the beam is 200 watts per square meter. Microwaves cannot produce that small a spot except from LEO = low earth orbit, which is shaded by Earth about 40 minutes out of each 100 minute orbit. Neil

 

[undidly]

charliebigspuds who started this thread did not say the energy was to be used on Earth.
He just said "creating energy in space".
Sending energy from space to Earth is pointlessly complicated.
The surface gets light energy all day rising to 1000 w per square meter at midday.
Photo cells or heat systems for Earth,solar turbines for anywhere else (off planet) in the solar system.

A turbine system is so reliable it could be sent to another star system and still be working when it gets there.

 

[theridane]

The surface gets light energy all day rising to 1000 w per square meter at midday.

And in Earth orbit you get over 1300 W/m² all the time. You can use a solar cell to claim over 50% of that energy, both on Earth and in space.

So why the hell would you use a turbine that has an efficiency so low that it can't be expresses with a 32-bit floating point datatype, is so hellishly heavy that it would engage the entire lifting capacity of all space-faring nations today for a quarter of a century and has a power output that can be matched by a flat watch battery?

You know, you could just as easily send a solar panel to another star. As a bonus you wouldn't have to accelerate a megaton of unreliable mechanical crap and moving parts but just a couple pounds of static works-every-single-time silicon. A solar panel has nearly infinite shelf life (250+ a according to some sources, over 1000 years according to others) if it is protected from UV rays, which are responsible for their degradation. A simple storage bay would do the trick.

 

[neilsox]

Peaking at 1000 watts at mid day may be correct for the top of Pikes Peak, but 300 watts is about the average daily peak for most locations. If we use concentrating mirrors that don't reflect the damaging part of the ultra violet spectrum, we can shade the giant solar panel in space from harmful UV and possibly some other submicroscopic stuff flying about in the solar synchronous orbit. Neil

 

[theridane]

As part of an optional test protocol, we are pleased to present an amusing fact: your turbine construct, if properly protected, would be able to light up an LED. A solar cell array (η=40%) with the same area would be able to light up my entire country (and still sell the leftover wattage to Germans for billions).

 

[undidly]

As part of an optional test protocol, we are pleased to present an amusing fact: your turbine construct, if properly protected, would be able to light up an LED. A solar cell array (η=40%) with the same area would be able to light up my entire country (and still sell the leftover wattage to Germans for billions).

"" light up an LED""

Just the one?.
Would that be a red LED or a blue LED?.
Show us a few numbers so we can see how you get that answer.