It is known that geothermal energy has many advantages over solar and wind systems. These advantages include: (1) unaffected by weather; (2) it is a base-load power; (3) it is stable and has high capacity factor over 90% in many cases; (4) it requires less land and has less ecological effect; (5) it has high thermal efficiency. The total installed capacity of geothermal electricity, however, is much less than those of solar and wind energies.