In What is Geothermal Energy? we have discussed how geothermal energy works—the science of it.
In this part we explore how geothermal energy works in practical applications, that is, how this energy source gets translated into useable power.
Geothermal energy has three main applications.
1. Direct use
2. Geothermal heat pumps
3. Electricity generation
In this segment we look at how geothermal energy is used directly. We will also review the myriad of direct uses for geothermal energy. In Part II, we discuss geothermal heat pumps. Finally, in Part III, we explore how geothermal energy works to produce electricity.
How Geothermal Energy Works in Direct Use?
Direct use (direct heat, direct-piped) of geothermal technology is the oldest, quite simple and the most widespread form of use of geothermal energy. People have been using geothermal energy in this way since the Paleolithic. Direct use means that the warm water or steam from the ground is piped into the residence or other construction to supply heat. The direct-use technology rests on a very simple principle: a well is drilled into a geothermal supply of warm water, water is pumped out and circulated through a radiator to provide heat. The used water is disposed of.
The technology of direct-use is fairly uncomplicated and inexpensive because the geothermal source is very close to the Earth’s surface. Due to its simplicity, this application is considered more economical and efficient than geothermal electricity generation. Several factors, however, may affect the effectiveness of direct use: the temperature of the water, the distance between the well and the place of utilization as well as the quantity of water that can be utilized effectively.