Spallation drilling technique would reduce geothermal costs

In California, an improved drilling method called spallation, which would benefit deep geothermal exploration, is under test. Funded by Google, Potter Drilling of Redwood City is the company taking the lead on the technology, made necessary by the very hard rock often encountered in geothermal prospecting. Jeanne Roberts of EnergyBoom recently wrote a terrific covering the technique and the company, and the link will take you straight to it.