How much of our energy comes from the sun?

[ericmark]

Did a BBC survey Hans Rosling: How much do you know about the world? question 8 asks "About BLANK of the world energy comes from solar or wind" I thought about this and there are just two main sources of energy either from the earth's core or from the sun and I know some geothermal energy is harvested but thought this must be rather a small amount.

Now oil, coal, and other items like these did come from the sun although a long time ago it was photosynthesise from the sun which produced the oil and coal so that counts as solar energy.

Wind is a odd one as some is due to solar but some due to moon orbiting the world same goes for tidal and tidal is missed from the question so I selected 10% the highest option however the answer it seems is 1% which clearly means 99% of our energy is geothermal or gravity generated as the moon goes around the earth.

OK I can see if the question was "About BLANK of the world energy comes directly from solar or wind" which would then exclude oil, coal and gas then the answer would be very different.

I do see this as a problem with any survey unless carefully worded in an unambiguous manor there will always be a question as to what is really being asked. This makes me lose all trust in surveys.

What does the team think?

 

[EddieM]

I would tend to agree with you, either directly of indirectly I would hazard a guess that the vast majority of the planets energy comes from the sun. (I stress that is a guess though!)

 

[plugwash]

dont forget nuclear

 

[big-all]

what part do the nutrients in the soil play
the gasses used and given off by plants
the water consumed and given off

or are we talking purely energy gained rather than recycled in the process
and what about the chemical energy from batteries and mixing element to get a chemical reaction
as plug says like nuclear

 

[wobs]

Both the Sun and geothermal energy are effectively nuclear. The Sun of course is well known for its fusion power, but about 90% of the heat from Earth's core is nuclear energy:

the vast majority of the heat in Earth's interior—up to 90 percent—is fueled by the decaying of radioactive isotopes like Potassium 40, Uranium 238, 235, and Thorium 232 contained within the mantle. These isotopes radiate heat as they shed excess energy and move toward stability. "The amount of heat caused by this radiation is almost the same as the total heat measured emanating from the Earth."

Read more at: http://phys.org/news62952904.html#jCp

If the core cooled (or when - in billions of years), the Earth will become a cold dead planet.

We get about 174PW (174*10^15) every hour from the sun.

We can't use all of it of course.

 

[EddieM]

what part do the nutrients in the soil play
the gasses used and given off by plants
the water consumed and given off

or are we talking purely energy gained rather than recycled in the process
and what about the chemical energy from batteries and mixing element to get a chemical reaction
as plug says like nuclear

First bit, is driven by photosynthesis, i.e. sunlight.

2nd bit those reacting chemicals will have had to have been "made" coz as well all know from thermodynamics, everything tends towards is lowest energy form (entropy) so without energy input, gas, oil, coal in the main those reactive chemicals cannot be made.

I guess the nuclear one is a good point, but as heavy elements are thought to be made from supernovas......

 

[big-all]

but the question is from the sun
so was the earth part off the sun at some stage otherwise any non vegetable matter giving energy is energy from the earth

 

[EddieM]

but the question is from the sun
so was the earth part off the sun at some stage otherwise any non vegetable matter giving energy is energy from the earth

No the sun is composed of hydrogen and helium, and is a huge fusion reactor. Earth is ultimately formed from the remnants of a supernova.

Apart from nuclear, no non living matter gives off any energy.

 

[ericmark]

OK reading replies then 99% of our power is got from.
Geothermal, Nuclear and non reversible chemical reactions.
With only 1% got from the sun and wind caused by actions of the moon.

If we look at energy produced by wave, currents and tide how can we separate how much is due to suns influence and how much is due to the moon?

If biomass is grown and used within 10 years or 10 billion years it is still using energy from the sun.

I am sure they mean direct from the sun not simply from the sun but even so how can any organisation measure how much we use.

If we look at The eden project under all that glass how can anyone calculate how much energy that is collecting? We have to remember every window in our house is collecting the suns energy it is also likely letting energy escape but even my cat is aware of the energy it traps.

As one starts to question one statement one starts to wonder how many more are flawed so one slowly gets to a point where unless one can work it out for ones self it all has to be taken in the same way as watching stars wars film.

 

[big-all]

but the question is from the sun
so was the earth part off the sun at some stage otherwise any non vegetable matter giving energy is energy from the earth

No the sun is composed of hydrogen and helium, and is a huge fusion reactor. Earth is ultimately formed from the remnants of a supernova.

Apart from nuclear, no non living matter gives off any energy.

so the question is new or added energy rather than recycling whats there

 

[EddieM]

but the question is from the sun
so was the earth part off the sun at some stage otherwise any non vegetable matter giving energy is energy from the earth

No the sun is composed of hydrogen and helium, and is a huge fusion reactor. Earth is ultimately formed from the remnants of a supernova.

Apart from nuclear, no non living matter gives off any energy.

so the question is new or added energy rather than recycling whats there

the only "new" energy earth gets, is from sunlight, cosmic rays, and stuff hitting us. apart from that nada!

 

[ericmark]

so the question is new or added energy rather than recycling whats there

I am sure I was taught about conservation of energy and how it can't be made or destroyed but only changed from one form to another?

 

[noseall]

All matter is energy. E=mc².
It is releasing it that is the difficult bit.

 

[wobs]

but the question is from the sun
so was the earth part off the sun at some stage otherwise any non vegetable matter giving energy is energy from the earth

No the sun is composed of hydrogen and helium, and is a huge fusion reactor. Earth is ultimately formed from the remnants of a supernova.

Apart from nuclear, no non living matter gives off any energy.

so the question is new or added energy rather than recycling whats there

the only "new" energy earth gets, is from sunlight, cosmic rays, and stuff hitting us. apart from that nada!

And tidal energy, which is largely from the moon.

http://hyperphysics.phy-astr.gsu.edu/hbase/tide.html#stid

Wave energy is the most expensive generally (sun powered), but tidal can be worthwile in the right location, its just that as a one off project, it adds to the cost.

As I've said in the past, if we continue to increase our energy consumption by 3% every year (an approx figure), then we will exceed the 174PW in consumption in the year 2794. And it will be very hot.

By 3985 we will exceed the total output of the sun.


Reasons why this won't happen include:
Population should level out due to urbanisation, development, conflict [delete as appropriate]. Population growth is currently at 1.1%.
We would need to have enough resources to use that much energy
It assumes constant growth, when we don't need to - OECD countries do not grow that much, it is developing countries that is pushing the growth rate, and when they develop up to a certain point, energy demands should level out.
We have to make sure it doesn't.
Add your own reasons on top of these.


But if we want to use lots of energy (a large population does), then we need energy density. Here are some examples:

Pumped stored water at 100 m dam height (hydropower)0.001MJ/kg

Wood fuel (C6H10O5)n 14 – 16MJ/kg

Coal (anthracite, lignite, etc.) 22 – 30MJ/kg

Nuclear fission (natural uranium in fast breeder reactor) 86,000,000MJ/kg

Nuclear fusion (Hydrogen, H) 300,000,000MJ/kg

Binding energy of helium (He) 675,000,000MJ/kg

Mass-energy equivalence (Einstein’s equation E=mc2) 89,880,000,000MJ/kg

Annihilation of matter and antimatter 180,000,000,000MJ/kg
http://lifeboat.com/ex/the.energularity
Although a Chuck Norris roundhouse kick is probably greater.

 

[foxhole]

Did a BBC survey Hans Rosling: How much do you know about the world? question 8 asks "About BLANK of the world energy comes from solar or wind" I thought about this and there are just two main sources of energy either from the earth's core or from the sun and I know some geothermal energy is harvested but thought this must be rather a small amount.

Now oil, coal, and other items like these did come from the sun although a long time ago it was photosynthesise from the sun which produced the oil and coal so that counts as solar energy.

Wind is a odd one as some is due to solar but some due to moon orbiting the world same goes for tidal and tidal is missed from the question so I selected 10% the highest option however the answer it seems is 1% which clearly means 99% of our energy is geothermal or gravity generated as the moon goes around the earth.

OK I can see if the question was "About BLANK of the world energy comes directly from solar or wind" which would then exclude oil, coal and gas then the answer would be very different.

I do see this as a problem with any survey unless carefully worded in an unambiguous manor there will always be a question as to what is really being asked. This makes me lose all trust in surveys.

What does the team think?

It's a simplified statement so people who read the Sun can understand it.