Pros of using geothermal energy:

1. After installed its free to use.
2. It's maybe the most reliable energy source, because there is little to go wrong, because it is simpler than most other power systems.
3. Renewable
4. Clean and green
5. We have a lot of under ground heat to use
6. The price of "free heat" won't go up
7. It is better for the environment than other sources