About Geothermal Drilling Techniques

Geothermal power is a form of alternative energy using the heat beneath the Earth's surface to produce energy. It is one of the cleanest energy sources available. Unfortunately, extracting geothermal energy requires specific drilling techniques and the power plants are expensive to build and operate.

How Do Geothermal Power Plants Work?

Geothermal power plants produce energy by digging deep wells into the Earth's surface. Dry steam or hot water is brought up through pipes and converted into electricity in the power plant. Power plants process geothermal energy in one of three ways. These are flash steam, dry steam or binary cycle. All three methods power turbines with steam to produce electricity.

Drilling for Geothermal Energy

The drilling technique for geothermal power is similar to drilling for oil. A drill bit spins through rock while being lubricated with wastewater or drilling mud to prevent friction. When pockets of steam are found, a plant will drill directly for the steam. Air pressure is used to break through the final layers of rock since mud from the drill bit would block the steam. Spillation is a new process being researched that involves using jet engines to inject water into the rock instead of pressurized air. Using high temperatures to crack the rock into small pieces is another new technology being utilized. These temperatures are achieved by injecting hot gasses into the hole or igniting oxygen and fuel in the hole.

Disadvantages of Geothermal Drilling Techniques

Accessing steam underground is dangerous. The force of the initial steam rising to the surface has caused earthquakes at geothermal power plants. Right now drilling for geothermal energy is more expensive than other sources of energy and is not widely used in the United States.