Matter & Energy

Matter is composed of atoms or groups of atoms called molecules. The arrangement of particles in a material depends on the physical state of the substance. In a solid, particles form a compact structure that resists flow. Particles in a liquid have more energy than those in a solid. They can flow past one another, but they remain close. Particles in a gas have the most energy. They move rapidly and are separated from one another by relatively large distances.

Direct Use of Geothermal Water

In addition to generating electricity, geothermal water is used directly in spas (balneology), to heat greenhouses (agriculture), and to speed the growth of fish and prawns (see aquaculture). The heat from geothermal water is used for industrial processes and for space heating in homes and other buildings. People in over 35 countries have developed geothermal water for such purposes.


Industrial uses of the heat from geothermal water include manufacturing paper, pasteurizing milk, and drying timber and other agricultural products. Geothermal waters are used in mining to speed the extraction of gold and silver from ore, and are also piped under sidewalks and roads to keep them from icing over in freezing weather.

Space Heating

One of the most common uses of geothermal water is for heating individual buildings or groups of buildings (district heating). A typical geothermal heating system supplies heat to buildings by pumping water (usually 60° C/140° F or hotter) from a geothermal reservoir. Heat from the geothermal water is transferred through a heat exchanger to city water contained in an adjacent separate piping system. This heated city water is then pumped into the buildings, while the geothermal water is injected back into the reservoir to be reheated so it can be used again.