Alternative Energy

Johnny Pneumatic

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What are all the currenly/near term technically possible ways to generate electricity?

I have solar:

PV cells
Mirrors that reflect heat to boil water into steam
Mirrors that reflect light onto PV cells
Solar wind towers(haven't been built yet; the prototype is supposed to be built soon I think. If you have any info about them please post)

Next Gen

Biomass:
Methane
Charcoal

Hydro:
Dams
Gorlov turbines
And here

Geothermal:
From geothermal features like in Ice Land

An idea I had that I'm running by the smarter people here: A giant version of a geothermal heat pump, like are used to heat or cool homes. Is there any reason why water pipes can't be drilled down 10+- miles to where it's effing hot? No matter where you are on Earth(on land), it's effing hot a few miles below your feet.
This is a huge amount of energy that could be tapped, far more than all the oil that's ever been on Earth. Tapping it wouldn't make it run out any faster than it will when the uranium, or whatever is causing it stops in a few billion years(or whenever it will stop) would it?

Wind:
Small to giant wind turbines

It's always windy on the ocean, why don't we have floating islands of wind turbines?

New type being worked on

Biofuel:
http://www.purdue.edu/UNS/html4ever/0007.Tao.biofuels.html

Not sure if this is on the level; perhaps someone here knows?

Biodiesel and eventually petrolium oil from already existing or engineered organisms

Nuclear:
Fission
Fusion(supposedly it's really going to only be 20 years away this time)

Hydrogen:
Using microorganisms to split water for the hydrogen.


Ocean:
ocean thermal power

Storing energy without petrol:

Carbon nanotube flywheels should be able to hold energy in the same or greater energy density as gasoline, correct? Magnetic bearings would be a frictionless and wearless bearing they could ride on.(these exist and are used in industry already)
 
SkepticJ said:
What are all the currenly/near term technically possible ways to generate electricity?

I have solar:

PV cells
Mirrors that reflect heat to boil water into steam
Mirrors that reflect light onto PV cells
Solar wind towers(haven't been built yet; the prototype is supposed to be built soon I think. If you have any info about them please post)

Assuming you mean Solar Tower:
Prototype in Spain was successful, they are now building one fullscale, I belive, in Australia Interesting project, hope they make it work.


Mosquito - Solar Tower Fan
 
Tapping hurricanes would seem to be the way to go.

Pumping water down to hot rock and back up as steamto drive turbines or provide direct heat is standard geothermal practice. How deep you have to drill depends on regional geothermal gradient. Obviously heat flow is highest in volcanic areas, which is why Iceland , New Zealand, Italy and Kenya have GE fields. In low heat flow areas, you must go much deeper. A 50,000ft well in hard rock would be a pricy operation and you would need a lot of them.

Pumping water down wells has consequences too- like lubricating faults , which may be contra-indicated in tectonically stressed areas. Also there's a drawdown effect- you eventually create cold zones around the wellbore. And drilling hot holes can have its own hazards, not to mention screwing up local aquifers.

ETA- SkepticJ- Have a look at Mosquito's " Windmill & Hurricane" thread.
 
An idea I had that I'm running by the smarter people here: A giant version of a geothermal heat pump, like are used to heat or cool homes. Is there any reason why water pipes can't be drilled down 10+- miles to where it's effing hot?

The world's deepest drill hole in Russia's Kola Peninsula has reached a depth of 40,000 feet (about 7 1/2 miles). This was started in the 70s. They've been working on it over 20 years to get to that depth. So I'm guessing that while it might be theoretically possible to drill holes 10 miles deep, it would be prohibitively expensive.

http://www.gi.alaska.edu/ScienceForum/ASF7/725.html
 
Soapy Sam said:
Pumping water down wells has consequences too- like lubricating faults , which may be contra-indicated in tectonically stressed areas. Also there's a drawdown effect- you eventually create cold zones around the wellbore. And drilling hot holes can have its own hazards, not to mention screwing up local aquifers.

ETA- SkepticJ- Have a look at Mosquito's " Windmill & Hurricane" thread.


How's water going to act like KY Jelly to a fault if it's contained inside a metal pipe? What about not using water, but instead an alcohol that has a very low boiling point?
 
I had this idea for Orions Arm, but since it's hard science fiction the idea has to be really possible to fit in the setting, so lightning as a power source.
The idea I had is this technology is used to give lightning the path to flow down. So would could decide where the lightning goes to by pointing the device at a storm. The problem is how do you store
lightning's power at the high speed it is discharged at? Do we currently have the technology, or could soon, to put lightning in a "battery"?
If so, this would be a huge source of power. How many bolts happen on Earth each day, over a million isn't it?
 
SkepticJ said:
I had this idea for Orions Arm, but since it's hard science fiction the idea has to be really possible to fit in the setting, so lightning as a power source.
The idea I had is this technology is used to give lightning the path to flow down. So would could decide where the lightning goes to by pointing the device at a storm. The problem is how do you store
lightning's power at the high speed it is discharged at? Do we currently have the technology, or could soon, to put lightning in a "battery"?
If so, this would be a huge source of power. How many bolts happen on Earth each day, over a million isn't it?

One random estimate I have is 8.6 million per day.
This site explains a few reasons why it's not great. They estimate ~10^6 to 10^7 Joules per hit reaching the ground.

The total power is then, optimistically, 1 GigaWatt. By covering the entire world in towers spaced fairly close together, you might produce as much power as a nuclear plant. Using a path for it to go down, like you suggest, might slightly increase the efficiency, but it's still very little average power.
 
The water isn't in a pipe while you are drilling the hole. Only once the hole is drilled and cased. There is a technique called "drilling with casing" but it's early days yet. It's expensive, slow and difficult. There were cases of fault lubrication in California back in the 70s. Used to happen in coal mines too.

It isn't necessary to drill 10 mile deep holes for geothermal energy. Better to select the areas where heatflow is higher to start with- like...Yellowstone, or mammoth... if you can find someone daft enough to drill there. (yeh, yeh, I know.)

Iceland has excess capacity if someone wants to run a cable across. There's one aluminium factory in Iceland that uses more power than all the towns in the country. This is good, but do we really want 80% of our power generation capacity sat on top of the one magma chamber?

In general, water is the best heat exchanger going. Geothermal temperatures are high enough to superheat water anyway, and unlike alcohol or glycol, it doesn't explode. Well it does of course, but it doesn't catch fire in the process. People on rigs see this as a plus.:)

I wonder about the whole energy shortage thing. We're sitting 8 minutes from a yellow dwarf star. It's raining soup up there. We're not short of energy- we're short of fuel. That's a short sightedness we need to shed.

Actually, the Yellowstone magma chamber could probably power most of the US, so long as
a) You don't mind turning the Park into a power plant.
and
b) You get it right , first time. (You probably won't get two shots at it. You thought Three Mile Island was fun? You really don't want that bottle to come uncorked.)

In addition, you might eventually cool the upper mantle plume, shut down plate tectonics and stop California defecting to the Chinese. Wake me up in fifteen million years. I want to see.
 
Soapy Sam said:
I wonder about the whole energy shortage thing. We're sitting 8 minutes from a yellow dwarf star. It's raining soup up there. We're not short of energy- we're short of fuel. That's a short sightedness we need to shed.

In one of my links in my first post of this thread there's a page that talks about the 3rd Generation of PV technology. Quantum Dot photovoltaics could eventually convert 66% of the light that falls on them into electricity!

It's not just energy though, we need hydrocarbons to create synthetic polymers. Polymers are vital to the modern world. We need to make oil making aquatic plants, and get them in the oceans long before we run out of oil.
 
Soapy Sam said:
The water isn't in a pipe while you are drilling the hole. Only once the hole is drilled and cased. There is a technique called "drilling with casing" but it's early days yet. It's expensive, slow and difficult. There were cases of fault lubrication in California back in the 70s. Used to happen in coal mines too.

It isn't necessary to drill 10 mile deep holes for geothermal energy. Better to select the areas where heatflow is higher to start with- like...Yellowstone, or mammoth... if you can find someone daft enough to drill there. (yeh, yeh, I know.)



Ah. Well this is only a problem where plate faults are, correct? There aren't that many plates, and we know where their fault lines are.


Correct. It's just a lot more effing hot at ten miles than one. Anywhere on Earth if one drills down about one mile it's at least 120 F correct? Obviously it's hotter than that in Iceland ect. at that depth... 120 F is enough to run Stirling engines. Drill in say the Arctic and the temp. difference between 120 and whatever the air temp. is would make the Stirling engines work even better
than in a tropical climate.
 
SkepticJ said:

Fusion(supposedly it's really going to only be 20 years away this time)

More than 20 years..

" If all goes well with the operation of ITER and the construction of the first electricity-generating plant that follows it, the first reliable commercially available electrical power from fusion should be available around 2045 "

http://www.iter.org/index_faq.htm
 
SkepticJ said:
How's water going to act like KY Jelly to a fault if it's contained inside a metal pipe? What about not using water, but instead an alcohol that has a very low boiling point?
it won't, but very quickly the rock surrounding the metal pipe will be cooled, and rock has pretty low thermal conductivity - so pretty soon your 10 mile deep hole in hot rock is a 10 mile deep hole in cool rock - so pretty soon you have a little temperature differential to generate power from.
 
Human power?

I don't know if this has been proposed before, or if it is even economically feasible. Why can't a couple thousand (million perhaps) of people be employed to ride exercise bikes fitted with generators?
 
Dilb said:
One random estimate I have is 8.6 million per day.
This site explains a few reasons why it's not great. They estimate ~10^6 to 10^7 Joules per hit reaching the ground.

The total power is then, optimistically, 1 GigaWatt. By covering the entire world in towers spaced fairly close together, you might produce as much power as a nuclear plant. Using a path for it to go down, like you suggest, might slightly increase the efficiency, but it's still very little average power.

So "Back to the Future" is wrong about lightning being 1.21 jigawatts of power? :D ;)
 
Tony said:
Human power?

I don't know if this has been proposed before, or if it is even economically feasible. Why can't a couple thousand (million perhaps) of people be employed to ride exercise bikes fitted with generators?

Yeah, that's something I've always wondered about. Surely every gymnasium should be at least self-sufficient in power terms, and quite possibly more.
 
SkepticJ- There are faults everywhere, not just at plate margins. Most of them, in stable areas, won't be under stresses anyway, so are no problem. Some will. You never know till it moves.
While the energy release from a near surface fault movement will be small compared to the energy released by deep earthquakes, it IS near surface, so significant damage can occur from very small tremors. Especially in areas with no experience of earthquakes.
 

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