Types of Geothermal Power Plant

There are following types of Geothermal Power Plants

Dry Steam Plants

It uses steam directly from a geothermal reservoir to turn generator turbines and produce electricity.

In this plants, high pressure hot water from deep earth is taken and utilizes it to drive generator through turbines.
When the steam cools, it condenses into water and injected back to the deep in the earth. Most of the geo thermal plants are flash steam plants.

Courtesy: US Department of Energy

It transfers the heat from geothermal hot water to another liquid.
The heat causes the second liquid to turn to steam, which is used to drive a generator turbine.

The geothermal electricity requires water or steam at high temperature of 300 ⁰F to 700 ⁰F.
There are seven state of USA which produces about 16 billion kWh or 16,238,000 MWh, equal to about 0.4% of total U.S. utility-scale electricity generation.
The USA is largest producer of geothermal electricity in the world.

Courtesy: CNBC

State of USA	State share of total U.S. geothermal electricity generation	Geothermal share of total state electricity generation
California	70.5%	5.8%
Nevada	24.2%	9.4%
Utah	2.2%	0.8%
Oregon	1.3%	2.2%
Hawaii	1.0%	0.3%
Idaho	0.5%	0.5%
New Mexico	0.3%	0.1%

The USA generated 88 billion kWh of electricity from geothermal energy in the year 2019. Indonesia is 2^nd largest producer of electricity of 14 billion kWh from geothermal energy.
The Kenya was the 8^th largest geothermal energy producer about 5 billion kWh from geothermal which was 46% share of total energy generation.

These system uses hot water from springs or reservoirs located near the surface of earth. American culture used hot mineral springs for bathing, cooking and heating.
Many people believe that hot water bathing from direct earth surface is beneficial for health.
Geothermal energy is also used for direct heating of buildings with district heating systems.
The hot water under the earth surface is piped into buildings for heat.
A district heating system provides heat for buildings in Reykjavik, Iceland.

The air temperature above ground level kept changing throughout the day and with seasons.
The temperature of earth 10 feet below ground level are in the range of 50 ⁰F and 60 ⁰F.
The soil temperature is usually warmer than the air in winter and cooler than the air in the summer.
Geothermal heat pumps transfer heat from the ground into building during the winter and reverse process during summer.