Enough carbon-free power for 25 million homes?
Geothermal offers enormous potential, especially for baseload generation, with minimal downside. We already have 3000 megawatts of geothermal capacity, and we could have 30,000 megawatts (enough for the aforementioned 25 million homes). What's stopping us? Bad public energy policy, especially lots of indirect subsidies for coal and nuclear that renewable sources never seem to get (due to an underfunded lobby), plus the fact that utility profits are tied to the volume of electricity sold, which only encourages the construction of more coal plants (the cheapest source of electricity as long coal mines and power plants can pollute for free), and discourages efficiency improvements.
Here's an enlightening report on the state of geothermal electricity production:
Geothermal, the 'undervalued' resource, sees surging interest