Volcanic energy

trini

sooo, i was thinking, why dont we use the heat from underground magma channels to boil water and drive steam turbines, seems like a pretty stable way to make power. has anyone tried this before?

SteamKing

A safer version of this is called geothermal energy. Iceland uses quite a bit of geothermal energy because of the volcanic activity on the island.

russ_watters

I suppose for the US, a lot of it is political: who wants to see a bunch of power plants at Yellowstone?

trini

maybe, but i think even environmentalists would approve of it when weighed against the equivalent fossil fuel savings. The biggest problem i could see arising would be formation of a 'cold spot' around the heat exchanger which would basically shut the plant down, though i suppose smart placement would eliminate this.

a google search shows that north america's volcanoes are in a chain along the entire west coast, running up through canada. i dont think its unreasonable to say a large chunk of the grid load could be supplied by these systems.

russ_watters

You'd be surprised. Environmentalist interference is a major problem for wind power, for example.
I'm not sure what you mean by that. You mean in the ground, cooling some of the media you're getting the heat from? Yes, proper sizing and placement and understanding the source is critical to proper operation of geothermal energy extraction.

Note; electricity isn't the only use for geothermal. Heating and air conditioning is sometimes done this way, but you don't need magma, a 50F aquafier will do nicely. Well, another issue is that I'm not sure all of those are necessarily all that accessible. If the volcano isn't active, the heat could be quite deep underground and difficult and expensive to access.

trini

what i meant was that if u had say a tungsten vessel buried in a hole next to a lava channel as your HX system, and enough heat was removed to allow the lava to solidify, the channel would plug up and the heat flow would be directed away from the HX.

you're right about the active volcanoes, though it would still be interesting to see how much power such a system could potentially generate. i mean you could boil HUGE amounts of water.

davenn

New Zealand also uses geothermal energy generation. The upper centre of the North Island is volcanically active and with the crust being quite thin, access to to heat is very easy.

from wikipedia....
"The power station was built in 1958, the first of its type (wet steam) in the world, and it is currently owned and operated by Contact Energy. A binary cycle power plant was constructed in 2005 to use lower-temperature steam that had already gone through the main plant. This increased the total capacity of the power station to 181MW. The Wairakei power station is due to be phased out from 2013, replaced by the Te Mihi geothermal power station. The Poihipi Power Station was built in 1996 at a nearby site in the same field."

Dave

Integral

One issue in the US is that most of those volcanoes along the west coast are in Wilderness areas. It is not easy to drill the wells needed when motor verticals are prohibited.

trini

wait a second, if the production capacity of that station is 181 MW, and according to wiki the total US energy consumption was 29.26 PWh in 2006, which equates to a power requirement of (29.26e+9/(365*24*3600))=927 MW, then 6 of these stations could power the entire US?

russ_watters

No, you need to get that "3600" out of there.

trini

hm i saw it said 181 MW, which i assumed meant a per second basis. i guess if its MWh then its not as great as i thought, though still a viable power source.

propalo

I’m going on thinking: when you get energy from volcano you discharge a bit of its energy potential. What about discharging 10-50% of this potential? even 100%? We kill two birds with one stone: a) prevent eruption with its catastrophic consequences; b) get a global amount of energy.
Possible ways: drainage well; special chamber; volcano’s own chamber or caldera. Moreover: the 3rd bird is application of volcanoes for energy storage, may be artificial ones.

Drakkith

The watt is defined as 1 joule per second. So 181 MW is simply 181 million joules per second produced. You either can't have watts per second, or it would be 181 MW seconds I guess. 181 MW over 1 hour is 181 MWH.

Drakkith

I don't believe eruptions are caused solely by the heat of the magma, but more from the buildup of pressure as the tectonic plates move around.

propalo

It's not told about mentioned plates. We are working only with energy they cause : heat and pressure

Drakkith

I don't think I can understand you here. What exactly are you saying?

propalo

Tectonic plates’ interaction causes volcano activity. It’s inner pressure and temperature erase that leads to eruption and release inner energy. Certainly it causes catastrophic consequences.
I want:
a) Prevent catastrophe (drainage);
b) Accumulate and make to work volcano’s energy (partially it implemented: geothermal plants are working over the world for decades. But they absorb only insignificant part of potential charge.)