Alternative energy sources? How about photons?

  • #1

Main Question or Discussion Point

I'm looking to get into the realm of science fiction writing and am currently working out how the main "SciFi energy source" works in this world I'm trying to make. Fusion reactors are the obvious go-to, but I wanted to get creative, that said: how plausible/effective would it be to directly harness photons as an energy source? Less as using sunlight with a solar panel and more trapping photons and using them to generate energy to power different devices.

The current idea is something called a Photonic Black Box, in which one can store photons. My only concern is that this could be either incredibly stupid or otherwise realistically ineffective compared to other hypothesized energy sources.
 

Answers and Replies

  • #2
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in which one can store photons.
Implies emissivity equals zero, therefore, impossible?
 
  • #3
Vanadium 50
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This reminds me of "Why do we need nuclear energy? We can just use electricity!"
 
  • #4
Implies emissivity equals zero, therefore, impossible?
So in layman's terms (aka terms I understand) the answer is this is stupid and I should stick to fusion or something else?
 
  • #5
This reminds me of "Why do we need nuclear energy? We can just use electricity!"
I'm not that dumb ;D
 
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  • #7
ZapperZ
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I'm not that dumb ;D
But you're dismissing that comment without thinking it through. Remember, YOU said this:

Fusion reactors are the obvious go-to, but I wanted to get creative, that said: how plausible/effective would it be to directly harness photons as an energy source? Less as using sunlight with a solar panel and more trapping photons and using them to generate energy to power different devices.

The current idea is something called a Photonic Black Box, in which one can store photons. My only concern is that this could be either incredibly stupid or otherwise realistically ineffective compared to other hypothesized energy sources.
You never described how a box of photons can actually be used!

In solar panels, one uses the HEAT energy from photons to heat water tubes. In solar cells, one converts the photon energy directly into free electrons inside the photodiode and creates electricity. You never explicitly described HOW to use these photons that you are trapping. How do you intend to harness their energy into useful form?

So actually, what you have said is analogous to Vanadium's quote, even if you don't realize it.

Zz.
 
  • #8
  • #9
You never explicitly described HOW to use these photons that you are trapping. How do you intend to harness their energy into useful form?
That's why I came here, I don't know enough about photons to explain this without throwing the science out of science fiction. I don't know if it would even be possible to use a photon as an energy source (and I reasonably had my doubts), so I figured you folks would know more.

But something I do know is that in a fission reactor you're turning water into steam to drive a turbine and this turbine spinning is what generates the electricity, hence the above comment of "Not being that dumb." I'm dumb about the hypothetical use of photons as the 'electron of the future', sure I'll give you that. But I'm not so dumb as whoever said the quoted comment about nuclear energy vs electricity.
 
  • #10
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I don't know enough about photons to explain this without throwing the science out of science fiction
If you don't know what you're writing about, shouldn't you write about something else?
 
  • #11
ZapperZ
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That's why I came here, I don't know enough about photons to explain this without throwing the science out of science fiction. I don't know if it would even be possible to use a photon as an energy source (and I reasonably had my doubts), so I figured you folks would know more.

But something I do know is that in a fission reactor you're turning water into steam to drive a turbine and this turbine spinning is what generates the electricity, hence the above comment of "Not being that dumb." I'm dumb about the hypothetical use of photons as the 'electron of the future', sure I'll give you that. But I'm not so dumb as whoever said the quoted comment about nuclear energy vs electricity.
In a fission reactor, you are turning energy that is given out during a nuclear fission, and converting it to heat, which in turn, turned water into steam to create a mechanical form of energy. This mechanical form can be used directly (steam engine), or converted into electricity (electrical turbines). Electricity generated is then used to power devices.

There is a clear chain of "events" here.

EM radiations have been used to convert its energy to heat. Solar water heater does that. EM radiations have also been used to convert to electrical energy directly via solar cells. But somehow, these are not the form of "energy" that you are looking for.

The problem here is that a "photon" doesn't carry that much kinetic energy in the first place, and the conversion factor sucks, for it to turn into useful form to power mechanical devices that either do work directly, or converting it to electrical energy without the use of solar cells. In the world of photonics, we use light to carry information or signal, not do work.

Zz.
 
  • #12
russ_watters
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That's why I came here, I don't know enough about photons to explain this without throwing the science out of science fiction. I don't know if it would even be possible to use a photon as an energy source (and I reasonably had my doubts), so I figured you folks would know more.
I'll try to be more charitable in my interpretation than some of the others (not saying I disagree with them...):

Photons are just "particles" of light. If you could store them in a box [with perfect mirrors], you'd have to take them out and consume them in order to to use them; e.g., store light from the sun in a box and then open it later to throw the light at solar panels, to generate electricity.

It seems like a pretty weird way to store energy to me. But maybe you're ok with that* and can build a story around how a perfect one-way mirror is used to collect sunlight and store it "fresh".

*Pretty much every piece of far science fiction technology contains an element of nonsense. That's what makes it science fiction....or rather why some people break off a separate category from more plausible near-term/realistic SciFi and call it "Science Fantasy", in which you would put Star Trek/Star Wars. Trouble is, a lot of people don't realize they are not plausible.
 
  • #13
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I know it is a tangent to the OP, but the idea of storing photons for later use reminded me of Bob Shaw's "slow glass."

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

I still remember reading that story, must have been almost 50 years ago.
 
  • #14
CWatters
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I'll try to be more charitable in my interpretation than some of the others (not saying I disagree with them...):

Photons are just "particles" of light. If you could store them in a box [with perfect mirrors], you'd have to take them out and consume them in order to to use them; e.g., store light from the sun in a box and then open it later to throw the light at solar panels, to generate electricity.

It seems like a pretty weird way to store energy to me. But maybe you're ok with that* and can build a story around how a perfect one-way mirror is used to collect sunlight and store it "fresh".
Presumably as the photons bounce around inside the box of ideal mirrors they exert a force on the walls? Perhaps all you need to turn it into a rocket is to make a small hole in one side?
 
  • #15
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Presumably as the photons bounce around inside the box of ideal mirrors they exert a force on the walls? Perhaps all you need to turn it into a rocket is to make a small hole in one side?
If this is all one wants, then why fuss around with a box of photons when one can just stick a laser on the spacecraft’s rear end?

Zz.
 
  • #16
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The current idea is something called a Photonic Black Box, in which one can store photons. My only concern is that this could be either incredibly stupid or otherwise realistically ineffective compared to other hypothesized energy sources.
On sci-fi basis it would be qualified as a kind of battery. But what would be the source?
 
  • #17
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If this is all one wants, then why fuss around with a box of photons when one can just stick a laser on the spacecraft’s rear end?

Zz.
Agreed. Not sure if that would satisfy the OP request to use photons as an energy source?
 
  • #18
stefan r
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... trapping photons and using them....
Here is a company making devices for residential use.
 
  • #19
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correct me if I'm wrong, but photons are energy carriers, not energy source. So the OP's idea of using photons as energy source is not possible.
 
  • #20
stefan r
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correct me if I'm wrong, but photons are energy carriers, not energy source. So the OP's idea of using photons as energy source is not possible.
That is also true for batteries and petroleum. With petroleum you could one step further and say that petroleum is not a energy carrier unless there is an oxidizer too.

My impression was that he was talking about Sun produced energy from nuclear fusion. Photons are emitted by the surface of the Sun. Photons are "trapped" and then used as needed. Here is a NASA article on solar fiber optics.

If you can build a perfect mirror then you can store photons and use them whenever you want. You could bottle magnified sunlight if the entire inside of the bottle was a perfect mirror.
 
  • #21
ZapperZ
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That is also true for batteries and petroleum. With petroleum you could one step further and say that petroleum is not a energy carrier unless there is an oxidizer too.

My impression was that he was talking about Sun produced energy from nuclear fusion. Photons are emitted by the surface of the Sun. Photons are "trapped" and then used as needed. Here is a NASA article on solar fiber optics.

If you can build a perfect mirror then you can store photons and use them whenever you want. You could bottle magnified sunlight if the entire inside of the bottle was a perfect mirror.
Do you know where I can buy this perfect mirror? I need 17 of them.

Zz.
 
  • #23
russ_watters
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Do you know where I can buy this perfect mirror? I need 17 of them.
In the 23rd century there is no money; just have the replicator make them for you.
 
  • #24
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Do you know where I can buy this perfect mirror? I need 17 of them.

Zz.
I get them at the Ideal Hardware Store. They're in the aisle past the massless springs. If you see the monopoles you've gone too far.
 

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