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Boiling Water In Space

Stop thinking of the sun as a ball of fire -it isn't, by the way.

"Water near the sun boils" is wrong. I mean it does boil, but it doesn't need to be there to boil.

Water in space boils because there's no atmospheric pressure...

You're missing the point, Trekker. The design (as I understand it) is proposing a sealed system, where the water will always be at a significant pressure because it cannot expand out of the manifold. The water isn't exposed to vacuum. The role of the sun in this system is just a ball of fire providing thermal energy.

It still wouldn't need to be near the sun to boil, it'd boil just fine in Earth orbit.
 
^Correct, the important part is being outside the earth's atmosphere, which is blocking a significant portion of the sun's energy.
 
This is incorrect. It takes as much force to move a mass in space as it does on Earth.
Maybe he's thinking of friction in the bearings? In a weightless environment, the bearings wouldn't be under much stress at all

He wasn't. And while it's technically true that gravity would contribute to bearing load friction, it's negligible enough not to make any practical difference. It would have to be balanced differently though.

I've worked with turbines a bit like this one:

afp107_svar_05.jpg


I helped to recondition one (replace and trim blades, balance, etc.) during a maintenance at the nuclear power plant I worked at at. It's in sections, but they are so finely balanced that when they're at rest and unlocked a person can easily rotate one by hand, weighing several tons. If a human being can easily overcome the drive shaft friction, imagine what several hundred thousand horses worth of steam energy thinks of it. :)

Tachy's idea is not a stupid one though, for once, though his applications are specious at this point in time.
 
More energy produced, more energy stored.

Do you have any evidence or calculations of any kind to back up that this would be more efficient? That you're not just pulling assertions out of thin air like in every other Sci-Tech thread you've started?

What produces more power on Earth and is more efficient at energy production, steam powered turbines in coal/nuclear power stations or solar panels??

In space there's no Earth gravity affecting the turbines meaning they will move even quicker and more effectively than in a gravity environment, obviously therefore producing far more power output.
"Far more" isn't a quantity. If you haven't actually run the numbers, the "Far more" you gain from moving the turbines into space could still be less than the amount of power that can be feasibly beamed back to Earth in a microwave relay. For that matter, it could still be less than the amount of energy you could collect with a large solar panel, without the added complexity and expense of turbogenerators and coolant loops.

If you haven't actually run the numbers, you're just guessing. There are a lot of variables you haven't even considered yet, and pretending they don't matter won't make them go away.

In the case of the batteries you only need fuel to transfer the batteries to and from Earth
Speaking of numbers: it currently costs something like $5,000 to move a kilogram of payload into orbit, and around $20,000 to bring it back. Battery transfer therefore gives you a $25,000/kg cost for each "container" of energy moved to and from the power plant. At a power-to-weight ratio of, say, 3.6GJ per kilogram (an absurdly high figure even with futuristic technology) the nominal cost to consumers--before market adjustments--is $25,000 per kilowatt hour.

To put that in perspective: there are terrestrial solar panels produce energy to consumers at costs of around $.2 per kilowatt hour.

Your case may be considered rested.
 
Is it just me who thinks the original poster should be in charge of making Rube Goldberg machines? Whether its building Pyramids to space, flinging the moons of Jupiter out of orbit and on a path toward Alpha Centauri or constructing space based steam turbines, we'd be sure to always have some sort of wacky needlessly complex invention around :lol:
 
Is it just me who thinks the original poster should be in charge of making Rube Goldberg machines? Whether its building Pyramids to space, flinging the moons of Jupiter out of orbit and on a path toward Alpha Centauri or constructing space based steam turbines, we'd be sure to always have some sort of wacky needlessly complex invention around :lol:

He certainly has an imagination, and that's good. Unfortunately, he doesn't have the engineering or scientific prowess to make good estimations or throw the red flags up two or three questions into the process.

Serious question for Tachy/Legend: have you ever considered, I dunno..... reading a few general science texts? I'm not asking you to go back to school, but since you obviously have an interest in these kinds of things perhaps you should consider it. I don't think you fully appreciate a lot of the answers and criticism we give you.
 
Speaking of numbers: it currently costs something like $5,000 to move a kilogram of payload into orbit, and around $20,000 to bring it back. Battery transfer therefore gives you a $25,000/kg cost for each "container" of energy moved to and from the power plant. At a power-to-weight ratio of, say, 3.6GJ per kilogram (an absurdly high figure even with futuristic technology) the nominal cost to consumers--before market adjustments--is $25,000 per kilowatt hour.

That's all wrong. You only need to get the materials up to construct the batteries. After that the batteries never leave space and the only other thing you need to send up now and again is fuel.
The Batteries will dock with an orbital transmitter which will beam the energy down to the surface of the Earth via Microwaves and then leave back to the powerplants.

The only thing that will cost anything in regards to the batteries is the fuel to get it to and from Earth orbit.

But I keep saying it and I'll continue to say it till I'm blue in the fingers. These powerplants could be used for space based colonies.
 
Right, because all the components that make a battery have no mass at all until they are a battery. Therefore, it'll be much cheaper to send up all the parts to make a battery, and all the tools required to make a battery than to send an actual battery.

:rolleyes:
 
Right, because all the components that make a battery have no mass at all until they are a battery. Therefore, it'll be much cheaper to send up all the parts to make a battery, and all the tools required to make a battery than to send an actual battery.

:rolleyes:

The guy was talking like the battery would keep getting dropped back down to earth and then launched back up again on a regular basis which is not the case, the thing will remain in space at all times.
Most of the cost will be getting it up there originally but once up there only fuel is required.
 
That's all wrong. You only need to get the materials up to construct the batteries. After that the batteries never leave space and the only other thing you need to send up now and again is fuel.
The Batteries will dock with an orbital transmitter...

The engine I liked, but this relay race of rechargeable batteries is unfeasible.

You're after moving them in and out of gravitational field of the sun, which means they'll need to be fitted with engines of their own, which would have to burn much more fuel than what you'd ultimately deliver. It would be a cumbersome and expensive setup for what energy you get out of it.
 
"only fuel":guffaw: You do realize that the cost of fuel will sink the idea? You would be better off just burning the fuel in a generator on earth to create the energy.

But yes, for a space colony, there is nothing wrong with the concept of a solar furnace.
 
That's all wrong. You only need to get the materials up to construct the batteries. After that the batteries never leave space and the only other thing you need to send up now and again is fuel.
The Batteries will dock with an orbital transmitter...

The engine I liked, but this relay race of rechargeable batteries is unfeasible.

You're after moving them in and out of gravitational field of the sun, which means they'll need to be fitted with engines of their own, which would have to burn much more fuel than what you'd ultimately deliver. It would be a cumbersome and expensive setup for what energy you get out of it.

Which is precisely why I keep saying that it's no longer about Earth but rather space colonies but some people can't seem to let the whole Earth part go.
I admit there are complications trying to get the energy to Earth, I've proposed batteries as a possible alternative because people are still talking about getting the power to Earth but truth be told it's no longer about Earth.
 
Replacing "Earth" in the example with a Space Colony doesn't change much, though. If this Turbine is in space, and it's trying to get energy to a location on the ground, the energy has to get there somewhere.

Options are to:

-Transmit the energy directly from the turbine to the end location. Probably the only way to make the idea fly, but there are complications. Not very efficient, and the farther you have to transmit the energy, the more you'll lose en route. After a pretty short distance, you'll have lost 99% of it. Again, depending on distance/location, you could also have planets, moons, comets, etc in the way, and you're trying to hit a target that's moving VERY fast with a microwave. More problems than you're allowing for.

-Ferry the energy there, via batteries, or something else. Not really feasible. Going to spend more energy on creating and moving around the batteries than you'll produce. Also, you'll now need people AT these facilities, right? How are the batteries getting pulled out, shipped to the destination,a nd new ones hooked up? At the receiving end, you've gotta swap old batteries for fresh ones, and then transmit the power to a ground station. Not sure how fast shipping will be, but you'll dissapate some of the battery en route. You've then gotta beam it down, losing another percentage. Between the microwaves, fuel for shipping the batteries around, and then keeping people alive at both stations, you're far in the red.

- A little easier if the colony is free-floating and not ground-based, but makes the colony itself MUCH harder to keep going, and the tradeoffs are worse. On the plus side, you could beam the energy directly there, so you don't lose that last bit. If the floating colony was NEAR the sun, could hook this turbine up directly to the colony, and bring in power via cables, which would probably work, but if it's hot enough to make water, you've got a lot of work protecting the colonists. And why is the colony floating near the sun, other than the turbine? And at that distance, wouldn't massive solar panels be easier to get going, just as efficient (no atmosphere in the way), and not require any extra work (no moving parts, no water loss, etc)?

-Could go with the turbine on the ground, but that already exists, is known about, and in use, and negates the entire space idea.

plenty to talk about, if you're actually interested in talking critically about it rather than looking for praise...
 
Replacing "Earth" in the example with a Space Colony doesn't change much, though. If this Turbine is in space, and it's trying to get energy to a location on the ground, the energy has to get there somewhere. .

This is where you fail. It's a space colony. In space. Next to the powerplant. All you need is about 6 feet of cable. Ok, that last sentence is exaggerating, but you get the idea.

The powerplant doesn't need to be "near" the sun anymore than the colony does. Like an earth based solar furnace it would concentrate sunlight using mirrors.
 
You're kidding, right?

Read the rest of the post you quoted before judging, as I addressed your "point".

Also, the mirror techniques you're describing are NOT the ideas talked about in the OP. He's basing this on boiling by distance from the sun, or later on by pressure. Different design, for starters.

And without atmosphere in the way, why wouldn't you scrap the turbine and just go with more solar panels? No moving parts, way less complicated with a lot less to maintain. And it's space, so uh, space, isn't an issue. Should be lighter/easier to get panels up into space than a big turbine and cooling system as well....
 
No, I am not kidding, I am just not reading more into what the OP said than what is there.

Also, the mirror techniques you're describing are NOT the ideas talked about in the OP.

True, but instead of continuing to attack a seeming silly idea, I tried to make it work.

or later on by pressure. Different design, for starters.

Not true, he never suggested this. The attackers of his idea did.

And without atmosphere in the way, why wouldn't you scrap the turbine and just go with more solar panels? No moving parts, way less complicated with a lot less to maintain.

Less to maintain? IDK, they have already had issues with the ISS panels ripping, and that system is only large enough to maintain 6 people.
It may be found that a solar furnace system scales better in the energy it provides than solar cells. Can't say one way or another at this point. And while individual solar panels may be lighter, they may take up more volume per Kw generated. This could actually result in more rocket launches, due to limits in payload size, than a solar thermal plant. Driving up costs.
 
IDK, they have already had issues with the ISS panels ripping, and that system is only large enough to maintain 6 people.

Upon deployment they ripped and NASA has gotten around that. But the ISS's solar panel generates more energy than needed. The power generation isn't what limits the ISS to 6 people.
 
Power use obviously depends on the processes you're running.

If we're talking about a remote space colony, you'll need to direct a lot of energy into oxygen production, and growing food. I believe the OP is intending for a large degree of independence in these space colonies he's hypothesizing.
 
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