GEOTHERMAL ENERGY

-


Skip to sub-navigation

Geothermal 

Geothermal power plants use hydrothermal resources that have both water (hydro) and heat (thermal). Geothermal power plants require high-temperature hydrothermal resources—300 degrees Fahrenheit (°F) to 700° F—that come from either dry steam wells or from hot water wells. We use these resources by drilling wells into the earth and then piping steam or hot water to the surface. The hot water or steam powers a turbine that generates electricity. Some geothermal wells are as much as 2 miles deep.

A geothermal power plant emitting steam.

A geothermal power plant emitting steam

There are three basic types of geothermal power plants:

  • Dry steam plants use steam directly from a geothermal reservoir to turn generator turbines. The first geothermal power plant was built in 1904 in Tuscany, Italy, where natural steam erupted from the earth.
  • Flash steam plants take high-pressure hot water from deep inside the earth and convert it to steam that drives generator turbines. When the steam cools, it condenses to water and is injected back into the ground to be used again. Most geothermal power plants are flash steam plants.
  • Binary-cycle power plants transfer the heat from geothermal hot water to another liquid. The heat causes the second liquid to turn to steam, and the steam drives a generator turbine.

Types of geothermal power plants

Illustration of a Dry Steam Power Plant - Geothermal steam comes up from the reservoir through a production well. The steam spins a turbine, which in turn spins a generator that creates electricity. Excess steam condenses to water, which is put back into the reservoir via an injection well.Illustration of a Flash Steam Power Plant - Pressurized geothermal hot water comes up from the reservoir through a production well. The water enters a flash tank where it depressurizes and flashes to steam. The steam then spins the turbine, which in turn spins a geneator that creates electricity. Excess steam condenses to water, which is put back into the reservoir via an injection well.Illustration of a Binary Cycle Power Plant. Geothermal hot water comes up from the reservoir through a production well. The hot water passes by a heat exchanger that is connected to a tank containing a secondary hydrocarbon fluid. The hot water heats the fluid, which turns to vapor. The vapor spins a turbine, which in turn spins a generator that creates electricity. The hot water continues back into the reservoir via an injection well. This closed-loop system produces no emissions.

Source: U.S. Department of Energy, Geothermal Technologies Office (public domain)

Comments

Post a Comment

Popular posts from this blog

Alternating Current

-
Image
  What Is Alternating Current? An  alternating current  can be defined as a current that changes its magnitude and polarity at regular intervals of time. It can also be defined as an electrical current that repeatedly changes or reverses its direction opposite to that of Direct Current or DC, which always flows in a single direction as shown below From the graph, we can see that the charged particles in AC tend to start moving from zero. It increases to a maximum and then decreases back to zero completing one positive cycle. The particles then reverse their direction and reach the maximum in the opposite direction after which AC again returns to the original value completing a negative cycle. The same cycle is repeated again and again. Alternating currents are also accompanied usually by alternating voltages. Besides, alternating current is also easily transformed from a higher voltage level to a lower voltage level.
Read more

Difference Between AC And DC Motor

-
  Difference Between AC And DC Motor The difference between AC and DC Motor are discussed below: AC Motor vs DC Motor AC Motor DC Motor AC motor runs on alternating current. DC motors operate on direct current. There is no need for conversion of current in AC motors. Like AC. There is no need for conversion of current in AC motors. Like AC. AC motors are used where power performance is demanded for extended periods of time. DC motors are used where the speed of the motor needs to be controlled externally. AC motors can be single-phase or three-phase. All DC motors are single phase. In an AC motor the armature does not rotate while the magnetic field keeps rotating continuously. In a DC motor, the armature rotates while the magnetic field rotates. Repairing AC motors is not expensive. DC motors are very expensive to repair. Brushes are not used in AC motor. Brushes are used in DC motor. AC motors have a very long life span DC motors do not have a very long life span. The speed of AC mot
Read more