Using Geothermal Energy on a Larger Scale
To utilize this energy source from the earth on a grander scale requires the building of power plants. Geothermal power plants tap into hot water and steam pockets in the earth. But, to reach these high temperature pockets or “reservoirs,” drilling has to take place. It is the drilling that causes the expense. One drilled well can cost as much as $1 to $4 million.
These wells fuel three different types of power plants. Dry steam plants use steam directly from the underground reservoir to rotate turbines and produce electricity. Flash steam plants pump extremely hot water through the well. Because of the high temperatures, some water turns to steam and spins the turbines. Cooled steam condenses into water and is recycled back into the earth.
The last type of geothermal plant is a binary cycle plant. How water from the earth is used to heat a contained liquid with a lower boiling point than water. At the point of boiling, the steam generated from the liquid moves the turbines and creates electricity.
While geothermal power is clean and produces far fewer gases (CO2, sulfur and N2O), it is still very costly to get going. What makes it so problematic is the drilling, as well as the geographic locations where these underground reservoirs are accessible. Until the cost of drilling and other factors fall in line, your best source of geothermal energy is a heat pump.
For additional information on geothermal power, check out the book “Geo Power: Stay Warm, Keep Cool and Save Money with Geothermal Heating & Cooling” by Donal Blaise Lloyd.