There is one major source of renewable energy that we have not yet mentioned on GoodCleanTech: geothermal. It may be on the verge of something, though; Al Gore recently installed a system in his house, and ScienceDaily mentioned it in the same breath as wind and solar.
Now, the Boston Globe has this article about a geothermal project in Switzerland, with this spectacularly ambiguous headline: "Hot rocks in earth's crust raise hope for clean energy, quake concerns." But almost any publicity is good publicity, right? (Okay, maybe not).
Well, never mind the quake concerns: we have those anyway. Let's focus on the clean energy!
How does geothermal energy work? Basically, by boiling water on rocks two or three miles underground. (So, this isn't quite the system that Al Gore had installed). There's a nicely detailed explanation here.
MIT released a study saying that if the US could tap 40% if its potential geothermal energy, then we could meet our energy demand 56,000 times. And investing about $1 billion now could generate more than 100 GW of electricity by 2050--equal to about 100 nuclear power plants.
Geothermal wells cost more than oils wells--seven to eight million dollars each (oil wells cost between one and two million). And rocks eventuall lose their heat, necessitating the drilling of new wells--but each well can last a matter of decades, which seems like a good investment to me.
So why hasn't geothermal been further explored?
Northern California has a geothermal power complex (pictured) called "The Geysers." As far as I can tell, it's a bit of a relic from the days when geothermal power was still being explored, back in the 70s. And it's still going--powering more than three counties. Nowadays, the U.S. government is only allocating two million dollars a year to geothermal power. So it needs some independent investors. It seems like a pretty safe investment to me, especially if Australian and Swiss firms are already embarking on big geothermal projects... then again, I don't have $10 million.