Thread: What % of solar energy is 'wasted' ?

1. I tried looking it up, but I can't do the math to get the answer.

According to Wikipedia,

(energies in joules)
1.5×1022J total energy from the Sun that strikes the face of the Earth each day
3.3×1031 J total energy output of the Sun each day

What percentage of solar energy does Earth receive, and what percentage is 'wasted' on ungrateful extraterrestrial lichen, or simply dissipates in the depths of deep space?

Orders of magnitude (energy) - Wikipedia, the free encyclopedia

2.

1.5×10 (22nd power) J
and
3.3×10 (31st power) J

c-J

4. Note sure what's the point in this simple geometry lesson or the value judgements about what happens to the energy

5. Originally Posted by citizen James5218

1.5×10 (22nd power) J
and
3.3×10 (31st power) J

c-J
Surely it is simply 100 x 1.5/3.3 x 10²²/10³¹ ~ 100 x 0.5 x 10⁻⁹ = 5 x 10⁻⁸ %, isn't it?

Though not sure what exactly you can do with this result…..seems to be a bit of a "so what"…...

6. Originally Posted by exchemist
Originally Posted by citizen James5218

1.5×10 (22nd power) J
and
3.3×10 (31st power) J

c-J
Surely it is simply 100 x 1.5/3.3 x 10²²/10³¹ ~ 100 x 0.5 x 10⁻⁹ = 5 x 10⁻⁸ %, isn't it?

Though not sure what exactly you can do with this result…..seems to be a bit of a "so what"…...
Yeah, you'd have to build a dyson sphere to capture the total output of the Sun.

7. Originally Posted by exchemist
Originally Posted by citizen James5218

1.5×10 (22nd power) J
and
3.3×10 (31st power) J

c-J
Surely it is simply 100 x 1.5/3.3 x 10²²/10³¹ ~ 100 x 0.5 x 10⁻⁹ = 5 x 10⁻⁸ %, isn't it?

Though not sure what exactly you can do with this result…..seems to be a bit of a "so what"…...
That is what is captured. 100 - that answer and you get basically 99.9% escapes.

8. ~ Perspectives of energies lost.. The maths o babble would drive a sane man mad.. What fraction of the Solar output reaches planet Earth when Earths magnetic shield does a convincing job of absorbance.. At 150 million Km ( 93 million miles ) and a surface face so small as to be almost totally in significant. As to be aware that the available Solar energy could make redundant the Petrochemical reliance.
Answering these questions would be a very difficult quest..
and of the Solar radiations that do reach the Earth what small fraction is used ? Practically none..
If by way of this question you wish to imagine you know the energy available.. Wow..
Could humanity build a massive Solar station receiver locked into a geostationary orbit..
How would we get that power down here ? 'Now' this is science fiction..

9. Originally Posted by exchemist
Originally Posted by citizen James5218

1.5×10 (22nd power) J
and
3.3×10 (31st power) J

c-J
Surely it is simply 100 x 1.5/3.3 x 10²²/10³¹ ~ 100 x 0.5 x 10⁻⁹ = 5 x 10⁻⁸ %, isn't it?

Though not sure what exactly you can do with this result…..seems to be a bit of a "so what"…...

The kind of answer I was looking for was something like

0.00004%

or

4 parts per trillion units of energy output. (or whatever the number is)

Yeah, can't "do" much with the result. But, it'd be interesting to have the answer in a more digestible form, that a layman like myself could understand. I enjoy contemplating things like this.....like, that it takes light about 8 minutes from sun to earth, or, that if the sun was the size of a baseball, earth would be smaller than a BB, almost 50 yards away, etc. Not useful info for everyday life, but interesting to me, nonetheless.

10. Originally Posted by Chucknorium
Originally Posted by exchemist
Originally Posted by citizen James5218

1.5×10 (22nd power) J
and
3.3×10 (31st power) J

c-J
Surely it is simply 100 x 1.5/3.3 x 10²²/10³¹ ~ 100 x 0.5 x 10⁻⁹ = 5 x 10⁻⁸ %, isn't it?

Though not sure what exactly you can do with this result…..seems to be a bit of a "so what"…...
Yeah, you'd have to build a dyson sphere to capture the total output of the Sun.

Ha! Very cool. I'd never heard of a "dyson sphere" before.

Actually, that is another way of looking at the question. Imagine the sun, contained inside of a hollow ball that has a diameter of 186 million miles (earth's orbit diameter). The earth would be represented by a tiny bump on the interior of that ball's otherwise smooth surface. What is the surface area of the "earth bump", compared to the rest of that hollow ball? That answer may approximate the answer I was originally seeking............how much solar energy goes to earth, vs how much goes 'everywhere else'.

11. Originally Posted by Schizoid
Originally Posted by exchemist
Originally Posted by citizen James5218

1.5×10 (22nd power) J
and
3.3×10 (31st power) J

c-J
Surely it is simply 100 x 1.5/3.3 x 10²²/10³¹ ~ 100 x 0.5 x 10⁻⁹ = 5 x 10⁻⁸ %, isn't it?

Though not sure what exactly you can do with this result…..seems to be a bit of a "so what"…...
That is what is captured. 100 - that answer and you get basically 99.9% escapes.

Yeah, I figured at least 99.9% escapes. I was hoping to get a more precise #

12. Originally Posted by astromark
~ Perspectives of energies lost.. The maths o babble would drive a sane man mad.. What fraction of the Solar output reaches planet Earth when Earths magnetic shield does a convincing job of absorbance.. At 150 million Km ( 93 million miles ) and a surface face so small as to be almost totally in significant. As to be aware that the available Solar energy could make redundant the Petrochemical reliance.
Answering these questions would be a very difficult quest..
and of the Solar radiations that do reach the Earth what small fraction is used ? Practically none..
If by way of this question you wish to imagine you know the energy available.. Wow..
Could humanity build a massive Solar station receiver locked into a geostationary orbit..
How would we get that power down here ? 'Now' this is science fiction..

I know.

This is the most inefficient solar system I've ever been associated with.

13. Originally Posted by citizen James5218
Originally Posted by exchemist
Originally Posted by citizen James5218

1.5×10 (22nd power) J
and
3.3×10 (31st power) J

c-J
Surely it is simply 100 x 1.5/3.3 x 10²²/10³¹ ~ 100 x 0.5 x 10⁻⁹ = 5 x 10⁻⁸ %, isn't it?

Though not sure what exactly you can do with this result…..seems to be a bit of a "so what"…...

The kind of answer I was looking for was something like

0.00004%

or

4 parts per trillion units of energy output. (or whatever the number is)

Yeah, can't "do" much with the result. But, it'd be interesting to have the answer in a more digestible form, that a layman like myself could understand. I enjoy contemplating things like this.....like, that it takes light about 8 minutes from sun to earth, or, that if the sun was the size of a baseball, earth would be smaller than a BB, almost 50 yards away, etc. Not useful info for everyday life, but interesting to me, nonetheless.
OK, if you prefer it as a decimal with zeros it is ~ 0.00000005%

But given how tiny the Earth is, compared to the radius of its orbit, that should not be a surprise. You can think of it this way. In round terms the radius of the orbit is about 100 million miles. So imagine a spherical bubble enclosing the sun at that radius. All its emitted energy must pass through the surface of that bubble. Then, if you compare the surface area of that bubble with the size of the Earth, you get a sense of what a tiny fraction of the total energy emitted is actually intercepted by the Earth.

Trouble is, the numbers involved are all telephone numbers, which is why in science exponential notation is used, to deal with all the zeros, as I did earlier. Counting the zeros would drive a man nuts.

14. Originally Posted by exchemist
Originally Posted by citizen James5218
Originally Posted by exchemist
Originally Posted by citizen James5218

1.5×10 (22nd power) J
and
3.3×10 (31st power) J

c-J
Surely it is simply 100 x 1.5/3.3 x 10²²/10³¹ ~ 100 x 0.5 x 10⁻⁹ = 5 x 10⁻⁸ %, isn't it?

Though not sure what exactly you can do with this result…..seems to be a bit of a "so what"…...

The kind of answer I was looking for was something like

0.00004%

or

4 parts per trillion units of energy output. (or whatever the number is)

Yeah, can't "do" much with the result. But, it'd be interesting to have the answer in a more digestible form, that a layman like myself could understand. I enjoy contemplating things like this.....like, that it takes light about 8 minutes from sun to earth, or, that if the sun was the size of a baseball, earth would be smaller than a BB, almost 50 yards away, etc. Not useful info for everyday life, but interesting to me, nonetheless.
OK, if you prefer it as a decimal with zeros it is ~ 0.00000005%

But given how tiny the Earth is, compared to the radius of its orbit, that should not be a surprise. You can think of it this way. In round terms the radius of the orbit is about 100 million miles. So imagine a spherical bubble enclosing the sun at that radius. All its emitted energy must pass through the surface of that bubble. Then, if you compare the surface area of that bubble with the size of the Earth, you get a sense of what a tiny fraction of the total energy emitted is actually intercepted by the Earth.

Trouble is, the numbers involved are all telephone numbers, which is why in science exponential notation is used, to deal with all the zeros, as I did earlier. Counting the zeros would drive a man nuts.

So.......in other terms......if the total solar energy output was represented by the distance between London and Sydney, the amount that earth receives would be equal to approx 1/8 of an inch.

I find that interesting. Thank you, exchemist.

15. Is it really wasted though in terms of natural radiation?
You could ask, how much of the suns energy is wasted by not being harnessed for other means!

16. Originally Posted by hannah40
Is it really wasted though in terms of natural radiation?
You could ask, how much of the suns energy is wasted by not being harnessed for other means!
Yes, "wasted" is a very anthropocentric way of looking at it. But the OP did put it in quotation marks, of course, so did not mean it literally.

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