I've posted this already in response to another thread, but I fell it's length warrants a thread of its own.

Here's something to spite all of green spewing solar fanatics.

TW = terawatts or 10e12 watts.
w/h = watt per hour and is a rate.

On average a square meter of earth's surface area receives 164 w/h, this combines for a grand total over earth of 84TW/h. Comparably we consume about 12TW/h. Solar cells currently are about 5%-18% efficient. This means that at the minimum if we covered earth in solar panels we'd get 4.2TW/h and at max 15.1TW/h. Mind you this average takes into account when the sun is shining and when its night time, ie if we were dealing with twelve hour days which promptly started and ended at full brightness the cells would, during the day, receive 328w/h. The assumption of 12TW/h also only covers current energy consumption. So if we suddenly introduced a large amount of hybrids, a 12TW/h figure is no longer accurate. Also contemplate an energy economy which is increasingly less dependent on fossil fuels and more dependent on electricity, average energy usage also increases. And of course also take into account that energy needs are always rising as the population and technology dependence increases.

So say by 2020 we're up to 15TW/h, we're pushing the limit of current solar technologies and covering the whole entire planet with solar panels. In fact this assumes one continious panel with no visible structural supports such as the "frames" which hold the panels togethor.

Say, hypothetically of course, that solar cells become 100% effecient and that we only need about 18% of the surface of earth to proved the 15TW/h. Logically this 18% would have to be in remote, sunny, and uninhabited places AND would have to the least ecologically destructive; ideally the solar cells would be placed in a desert. Land accounts for 1/3 of the area on earth, and about 1/3 of that land is desert. That means that deserts could provide 1/9, or 11 of 19 percent needed for solar cells. The other 8 of 19 percent...well...that'll just have to go into your backyard.

Either way no system designed for conversion of energy is nearly 100%, and mind you we'll be lucky to get 50% out of solar cells. Combined with wind and whatever "renewable" energies, barring hydroelectric dams, aren't going to cut it...ever. Before anyone blurts "LOL WHATTABOUT HYDROGEN!!!111!!!one!!" hydrogen is generated by electroylsis in a lossy endothermic reaction. This puts energy into the hydrogen making it a fuel with less energy then it took to make, and while hydrogen could be used in a cell to power a car, it's never going to power you home or infrastructure. Personally I think it's time Al Gore and his cronies owned up to thier frauds. We humans have always been hunters, gathers, and scavengers, in the quest for energy. The only reliable energy source now is fission driven nuclear power, which we have about 600 years worth the fuel for. In that 600 years money should be invested into more effecient renewable sources, but with the understanding they'll never replace gathered energy sources. Money for energy research should be invested into mainstream, and slightly obscure nuclear fusion schemes, from ITER and JET to the lowly fusor and polywell.

Feel free to constructively critize, but please remember figures are averages and estimates. Hopefully the gross fallacy of renewable energies is exposed without getting into the fine details.

Sources:
avg solar energy and avg consumption: https://zebu.uoregon.edu/disted/ph162/l4.html

photovoltaic cells: http://en.wikipedia.org/wiki/Photovoltaic_module

deserts: http://en.wikipedia.org/wiki/Desert

Earth (Land): http://en.wikipedia.org/wiki/Earth#Surface

ITER (Which isnt online yet): http://en.wikipedia.org/wiki/ITER

JET (Which is online and has a Q of .7 last I recall):http://en.wikipedia.org/wiki/Joint_European_Torus

Q is the measure of effecieny Q<1 means losing energy Q=0 no net loss or gain Q>1 net gain. Commerical reactors need about Q=15-22 to be viable.

Polywell: http://en.wikipedia.org/wiki/Polywell

 

Solar power is not as absurd. I didn't have the time to carefully look over your long post. But, your logic is failing somewhere. If we had cheap cells available that were 50 percent efficient, the markets would be booming more than theuy already are.

Currently, solar power pays off in about 10 to 15 years.

Europe is going crazy with solar power. I know someone that has their roof covered with solar panels. They sell their surplus energy back to the power company at the market rate dso that their electric bill is only $15 per moth.

Solar power is not the final answer to the world's energy problem, but, it is considered as one source of renewable energy.

 

Essentially, all energy on earth is solar power, stored in living tissue, fossil fuels, or aqueous temperature gradients. One may make a case that tidal energy is not solar power, and neither is nuclear energy or geothermal, but the energy that is responsible for most life on earth is solar.

 

Exactly why is it absurd? I'm not going to read that long post right now cus chances are it'll make me start throwing up again

 

To supply all of the world's power on solar operating at 50% you'd have to cover nearly 40% of the earth's surface which isn't feasible for many reasons.

I'm not disagreeing with what you said, I'd even bite that tidal forces are influenced by solar activity. However all the "solar" energy that we use ie fossil fuels, has been stored and concentrated over millions of years, and apparently we're going to run out of millions of years of stored energy after have only been using it for 150 or so years. And absolutely all life is solar. Plants are the primary producer in any ecosystem, and everyone else is a consumer losing energy in each exchange of energy.

Get well. Come back at your leisure?

 

It's absurd because he insists on talking about solar panels down here on earth, instead of in space which is the blindingly obvious place to put them.

 

gotcha, thanks. I'm going to try and find that thread that I think Shake posted awhile back about a major solar energy breakthrough, it makes the whole concept a lot more practical, and we would be just fine keeping panels on Earth if it works.

 

So, if I were to stipulate that your figures are correct (which I don't), what's your alternative, given that non-renewable energy sources, by definition, will be exhausted at some point?

Tick...tick...tick...

 

How do you get the power down to earth? All e&m (microwave/radio) fields dissipate by 1/r^2 factor. Surely you're not suggesting tethers? And realistically how do you propose to launch space based photovoltaic cells or even a giant reflecting mirror? Conventionally it's really expensive, hopefully in the nearish future prices will drop to around $1000 /kg into low orbit. Most photo cells need lots of heavy glass as well. Space based cells in the next 100 years or so looks pretty meek.

I'm interested.

 

https://forum.xnxx.com/showthread.php?t=54133&highlight=Solar

 

Short term, nuclear fission/hydroelectric. Long term nuclear fusion. ITER claims in the next 50 years to have a demo fusion plant running...which is possible but they're always a bit behind schedule. Deuterium (heavy water), fusion fuel, occurs naturally in sea water 1 in 5000 parts. It's relatively easy to separate out. Canada actually uses heavy water as a moderator in its commercial fission plants. The proposed reactions are:
(1)

21​

D +

31​

T →

42​

He ( 3.5 MeV ) + n0 ( 14.1 MeV ) (2i)

21​

D +

21​

D →

31​

T ( 1.01 MeV ) + p+ ( 3.02 MeV ) 50% (2ii) →

32​

He ( 0.82 MeV ) + n0 ( 2.45 MeV ) 50% (3)

21​

D +

32​

He →

42​

He ( 3.6 MeV ) + p+ ( 14.7 MeV ) (4)

31​

T +

31​

T →

42​

He + 2 n0 + 11.3 MeV (5)

32​

He +

32​

He →

42​

He + 2 p+ + 12.9 MeV (6i)

32​

He +

31​

T →

42​

He + p+ + n0 + 12.1 MeV 51% (6ii) →

42​

He ( 4.8 MeV ) +

21​

D ( 9.5 MeV ) 43% (6iii) →

42​

He ( 0.5 MeV ) + n0 ( 1.9 MeV ) + p+ ( 11.9 MeV ) 6% (7i)

21​

D +

63​

Li → 2

42​

He + 22.4 MeV (7ii) →

32​

He +

42​

He + n0 + 2.56 MeV (7iii) →

73​

Li + p+ + 5.0 MeV (7iv) →

74​

Be + n0 + 3.4 MeV (8) p+ +

63​

Li →

42​

He ( 1.7 MeV ) +

32​

He ( 2.3 MeV ) (9)

32​

He +

63​

Li → 2

42​

He + p+ + 16.9 MeV (10) p+ +

115​

B → 3

42​

He + 8.7 MeVThe most likely reaction is D+D, and as you can see its an extremely energetic reaction. 19grams of fuel is worth 12e23 * 2,450,000 eV. 1eV = 4.45e-23 watts/h. For simplicity the __e23's cancel out. That means that 19grams of Deuterium you get 4.45*12*2,450,000 = 130,830,000 watts/h -> 131MW/h. So to fufill 15TW you'd need about 2000kg..hopefully I haven't lost any zeros there. Anyways with water 1g = 1ml and 1kg = 1 liter, so 2000L of fuel to power the world. And the ocean has [FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]"So the total number of ocean liters will be 1.32 billion trillion liters. (This number in scientific notation is 1.32 x 10 to the 21st.)" (FSU Planeterium)[/SIZE][/FONT] I'd go ahead and say we're set for awhile when fusion powered plants kick in.


http://en.wikipedia.org/wiki/Nuclear_fusion#Criteria_and_candidates_for_terrestrial_reactions

http://www.unitconversion.org/energy/watt-hours-to-electron-volts-conversion.html

http://www.frostburg.edu/planetarium/aug05.htm

 

The entire article was about how solar energy is stored. MIT guys want to put it into catalyzed electrolysis and then fuel cells, rather than traditional batteries. The big break through it seems is in the catalysts used. It still doesn't solve the big problem which is the amount of solar energy available vs efficiency/space to put photovoltaic cells.

 

Incase you hadn't noticed, in the next decade we'll be getting so much solar energy it could potentially kill us. Hell, it's already starting. So why not use that energy for good instead of for cancer?

Nuclear energy is hardly safe.

 

Not to mention that he assumes that solar power will be powering everything.

 

If you're referring to global warming, you know the build up of green houses gases, we'd be about the same amount of light. Nuclear accidents happened because of poorly made automated systems. We've come a long way with computers since 3 mile island days.

What besides nuclear and solar do you propose given oil has collapsed?

Solar is responsible for all forms of energy on the planet except for geothermal and nuclear. Fossil fuels are made of plants and animals that ate plants and were compressed underneath the ground for sometime and turned into oil. Plants feed off the sun, animals fed of the plants, fungi off, of the animals..etc all a solar powered chain. Wind comes from pressure differences which are created by heat which is made by sunlight. Water cycle powers the hydroelectric dams; water cycle is solar based. Burning biomass...biomass comes from..well solar!

It just so happens that solar panels are the most direct form of solar energy light -> electricity. And the chain of energy conversions that's the smallest tends to be the most efficient.

"This is often paraphrased as "All other things being equal, the simplest solution is the best"

 

No, I'm referring to our weakening magnetic field, as well as the ozone layer. Without a strong magnetic field and an ozone layer without holes in it, nothing stops that solar energy and energy from space from entering our atmousphere. I don't believe in global warming.

Nuclear energy will never be safe because it's such a volatile, unpredictable thing. No matter what, accidents are going to happen, and let's not forget all of the radiation and leakage or the fact that it's impossible to safely get rid of all of that nuclear waste or the core after the plant gets shut down.

It's just not worth the risk.

 

Hydrogen.

 

Hah! I'm impressed I don't believe in global warming either.

 

Fuel cells or fusion of?

 

Fascinating. You dismiss solar because there isn't enough of it, but you hang your hat on hydroelectric, which there's even less of, and nuclear fusion, which has never been successfully demonstrated.

Isn't it possible that we're going to need all of the above, in addition to limits on population and intensive conservation? Why put these sources in artificial competition with each other?