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Alaska Looks To Volcanos For Geothermal Energy
Iddo Genuth writes "Alaskan state officials have recently announced their intention to begin funding the exploration and surveying of Alaska's largest volcanoes in hopes of utilizing these as a
source of geothermal energy. They say this volcano could provide enough energy to power thousands of households, and according to some estimates, Alaska's volcanoes and hot springs could supply up to 25% of the state's energy needs."
Well, actually, if you drill a big hole in the ground, you could pipe water down an enclosed pipe. Then the steam would come up another pipe to power generator turbines. When it cools back down to water, you send it back down to heat up again.
After your initial water investment, you wouldn't really need a significant amount of additional water at all if it was a closed system. I believe that's the general principal in most Geothermal usage wells.
Give a man a fire and he'll be warm for a day. But light a man on fire and he'll be warm for the rest of his life.
i was surprised to read that The Geysers, just north of San Francisco, claims to be "the largest complex of geothermal power plants in the world". i guess "largest" is open to interpretation. But here's another startling claim: "The Geysers satisfies nearly 60 percent of the average electricity demand in the North Coast region from the Golden Gate Bridge to the Oregon border".
who knew ?
The CSIRO in Australia has been investigating the practicality of producing electricity from granite deposits since the early nineties. Also since the nineties the same organisation has been saying that Australia could produce all it's power and then some from either solar or wind.
The problem for the last 11yrs in this country has been purely political as we stood stubbornly by the US. Because of this misdirected loyalty our power generation remains 90+% derived from coal and we have seen many innovations payed for by taxpayers sold off to private companies in the EU and elsewhere.
Now that our breadbasket (the Murry-Darling basin) is regularly producing half of what it did just a couple of decades ago people are starting to pay attention.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Even if you succeeded in running Anchorage off geothermal, what the hell are you going to do for the rest of the state? At best, this is a ploy to get more resources into the Mat-Su valley which isn't all that bad, but I don't see this as a big starter for most of the state or, more generally, for down South (ie, everywhere else). Powerlines to Seattle would cost an awful lot of money.
Faster! Faster! Faster would be better!
Geothermal power is nice, but does have its limits. There are reports suggesting that heavy use of geothermal power can increase the frequency of mini earth tremors, which is probably not good. Also, you are not generally tapping the earth's core (which has plenty of heat) but some local magma reservoir (which has rather less) or a channel through which magma flows (which is not much of a reservoir at all, and could in principle be blocked, which may explain said earlier reports).
In the long term, fusion power is the best solution, but the technology necessary to achieve fusion is taking a painfully long time. I still favour rounding up the fusion scientists, locking them in a building in Alaska with as much money as they can possibly need, and slowly turning down the heat until they quit with the politicking and bitching about whose method is "better" and get something that works.
In the short term, fusion isn't going to happen nearly fast enough to handle the present or any future oil crisis. Geothermal power can. As others have mentioned, other countries use it extensively, such as Iceland and New Zealand. Alaska could probably benefit from it, and the Pacific Northwest is riddled with volcanoes and magma reservoirs. The Pacific Northwest is also a major energy user, making it an ideal place to have major generators.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
That's cute. Ummm, what on Earth (no pun intended) are you talking about and how did you get modded informative?
We will probably never get *any* energy from the Earth's core at all. The crust of the Earth alone is 3-5 miles thick under the oceans and 15-35 miles thick on the continents.
Now, the Earth's core is thought to have at least half to ninety percent of it's energy generated from nuclear decay. That means we CANT draw all that energy off at once, even if we could draw it all in the first place. We would be rationed. There is also tidal forces to consider as well. The orbit around the Sun and the Moon for example can generate large amounts of energy in the Earth's core too.
Drilling even 20,000 feet is an ACCOMPLISHMENT. To my knowledge, and I have been on drilling rigs and know people in drilling companies, we have never broken 50,000 feet commercially. So ANYTHING we do is going to be in the CRUST, and not the mantle and certainly not the core. To get to the mantle of the earth on a continent we would have to drill in excess of 75,000 feet. I am pretty sure that at that depth concrete won't do it to create a stable pipeline and you will need some pretty neat material to withstand those stresses and keep a hole open.
Furthermore, the Sun provides an incredible amount of energy. Off the top of my head I think it is near 400 watts per square meter or approximately 1.8*10^17 WATTS total at any given time. That's a lot. 90%+ of the energy present in the crust of the Earth comes from the Sun. The core is providing a negligible amount of that power and most is probably received through direct volcanic activity and not emissions. Don't quote me on that, it's just a guess.
Considering that, in 2005 we required nearly 500 quadrillion BTUs of energy for the whole planet. Nearly 700 quadrillion is projected to be required in 2030. So let's just top that off at a nice quintillion BTUs. After multiplying that by .293 to convert to WATTS we get 293 quadrillion WATTS of energy. That is also PER YEAR. How much of that can be provided by the energy received from the Sun in the crust? 100%.
So basically the Sun can give us all the energy we will need for one year in one day and probably be done before breakfast is over.
We would have to use ALL the energy from the crust of the Earth FASTER than the SUN can replenish it BEFORE we could even begin to siphon off energy from the core.
So yes, you are correct that the energy at the Earth's core is not unlimited, nor is energy unlimited in the Sun or from any orbit. However, for a VERY LONG TIME we would only be able to suck a small droplet of blood of what is sure to be a gargantuan beast of energy. To say we could ever consume enough energy to surpass the energy provided by the Sun at any one moment is just fantastic, awesome, and up there with the Tooth Fairy.
You may also want to consider that the 293 quadrillion BTU requirement represents an INCREDIBLE amount of waste and inefficiency with our processes. I bet that by the time we get to 2075 (if we are not dead already) it will be because we figured out how to survive on far less than that.
The "Big Island" of Hawaii has a geothermal plant rated at something like 25-35 megawatts, which is a meaningful fraction (though not 25%, maybe more like 10%) of demand. More geothermal could be exploited, but there are issues of land ownership (lots of the volcanic stuff is federal land) as well as cultural, religious and environmental sensitivity.
In a heat engine, there is a maximum theoretical efficiency which may be achieved. This is dependent on the difference in absolute temperatures between the hot and cold reservoirs. For example, if your hot reservoir is 1000K, and your cold is 300K, the maximum theoretical efficiency is 1-300/1000 = 70%. In the coal plant you were referring to, the actual efficiency is likely very near the theoretical efficiency (mechanical engineers have done a good job at achieving high efficiencies with mechanical systems). It is impossible to improve upon that without violating the laws of thermodynamics.
Of course, no moving parts means that you may be able to operate at much higher temperatures (you'd need a ceramic PEM to sustain the higher temperatures).
Same applies to Iceland, of course.
PHEM - party like it's 1997-2003!