Slashdot Mirror
Iceland To Drill Hole Into Volcano
G3ckoG33k writes "BBC reports that Iceland will drill a hole into a volcano so it can tap heat from it, which eventually is hoped to produce commercially available energy. From the article: "Twenty years ago, geologist Gudmundur Omar Friedleifsson had a surprise when he lowered a thermometer down a borehole. 'We melted the thermometer,' he recalls. 'It was set for 380C; but it just melted.'". Excuse me, Gudmundur, but how could that ever have been a 'surprise'..."
And for those of you wondering exactly what the hell he is talking about: Inferno, a Doctor Who story, in the first season of the third Doctor. It's pretty decent Who story, where a similar experiment ends up blowing up the world (they drill completely through to the crust though). Which the Doctor witnesses in a parralel universe, so he can warn his own universe of the dangers of the experiment. Throw some weird green hairy zombies in, to make sure you do not forget it is Doctor Who. :P
:)
After watching Doctor Who for the first time with the new series last year, I've actually started going through all the old Doctor Who stories I never saw in chronological order, and boy is there a lot of (26 seasons, to be precise). And I just happened to have watch Inferno yesterday, so it is fresh on my mind, and was actually the first thing I thought of when I saw this newsbit also.
Okay. Everybody's joking about it, but here's the solution to the puzzle of the "surprising" heat: that's 380+ Celcius *WATER*, not lava. The area being studied is on the sea floor or kilometres beneath the land surface, and the water is under great pressure. As a result, it gets much hotter than surface water, without boiling. Sometimes the "water" in the sea floor close to these volcanic areas is a supercritical fluid -- beyond the temperature-pressure conditions for distinct gaseous and liquid phases.
Supercritical water is pretty exotic stuff in power systems. There are some advanced fossil-fuel power stations that use it, and supercritical nuclear power systems are being developed. They offer higher thermal efficiencies. In Iceland, they might be able to get the same thing going, but with renewable geothermal sources, which would be great, but first they have to tame some pretty extreme conditions in the boreholes.
The summary is bullshit, even by /. standards. They were drilling for conventional geothermal energy, that is water heated by a lava flow nearby (extremely common in Iceland). Given the high pressure they were expecting high temperatures (the quoted 380) and still liquid water (due to the pressure). What was surprising is the fact that the water was probably more than 500 and actually melted the thermometer. Given this discovery (aka The water in this depth is much hotter than previously calculated) it makes perfect sense to a) explore the reasons for the higher temperature and b) use that for a more efficient power plant. There's no volcanoes involved at all.