I remember reading about this geothermal project being cancelled due to concerns over (relatively) small seismic events caused by the drilling. Have there been any instances of, or reasonable scientific cause to believe a major seismic event might happen due to geothermal drilling?
Short answer: yes.
Longer answer: There's a statistically significant positive correlation between EGS and seismic activity.
Longer, peer-reviewed answer: http://escholarship.org/uc/item/0t19709v
BTW, the path I used to find that was
- Your link
- Google: "Besel geothemal" (mentioned in the article)
- Wikipedia "Enhanced geothermal system" (fourth from the top)
- Wikipedia "Induced seismicity in Besel" (linked by #3)
- Wikipedia "Induced seismicity" (linked by #4)
- Endnote 9 (citation on the sentence in #5 that says there's a link)
And no, I didn't read the paper, I'm (uncritically) assuming that Wikipedia wouldn't get the cite backwards on something that obscure. ;-)