Drill, Baby, Drill… for Geothermal!
A week ago, the USGS updated its official estimates of U.S. geothermal energy resources for the first time in over 30 years. During the past three decades, we’ve made significant progress on technology to exploit geothermal energy in areas where there’s plenty of heat in the ground, but no natural hydrogeologic plumbing system to help us exploit it. In other words: We are much better at cracking rocks underground than we used to be.
Assuming that this type of rock-cracking technology (aka “enhanced” geothermal systems) continues to work out as well as expected, the new study estimates that the equivalent of 50% of the nation’s current electricity supply is just sitting around in the ground in the Western U.S. That’s less than the 150% of current electricity that we could get if we blanketed the windiest 6% of the nation in windmills (source), but it is still nothing to sniff at.
Here’s where we should be drilling:
This map of potential enhanced geothermal resources really just shows subsurface temperatures, which means it’s really a map of what’s been happening in the mantle over the past 30 million years. You can see lots of tectonic features. Check out:
- Yellowstone and its associated hotspot trail, cutting a swath through Idaho
- the Rio Grande Rift, stretching up through New Mexico
- the Salton Trough at the very bottom of California – we think of the Pacific-North American plate boundary as being a strike-slip system, the San Andreas. But when you get far enough south… the Gulf of California actually has just a wee bit of rifting going on.
- the sharp transition from the part of North America overlying the cold Juan de Fuca slab, to the part of North America overlying the still-cold-but-warm-enough-to-give-off-volcanoes Juan de Fuca slab