# Geothermal industrial heat

Figure 1. Geothermal hot spots around the world.[1]

Geothermal industrial heat is the use of the Earth's natural thermal energy in order to provide heat to industries.[2] There are locations on Earth that may make better use of this, due to being situated on "geothermal hot spots" (shown in Figure 1 below) where they have access to higher underground temperatures.

Temperatures above 40°C and less than 150°C are ideal for these applications, since geothermal temperatures above 150°C are better used for geothermal electricity generation.[3] Between 90°C and 150°C is considered a "moderate" temperature range,[4] which is most commonly used in these applications.

## Uses

Essentially any industry heating need can be fulfilled by geothermal heating, as long as they do not require extremely high temperatures. Geothermal heating can substitute for fossil fuels and maintain industrial production year-round.[4]

Industries that use this heat include pulp and paper, cement, food, aquaculture, lumber, and more.[5] For example, in the lumber and cement industries this heat is used to dry the materials being produced. Greenhouses also commonly use this energy to provide fresh produce year-round.[6] Light industries like dairies and mushroom growers can benefit from the lower temperature range of geothermal heating.

It is hoped that geothermal industrial heat can be tapped to its full potential by developing countries in order to provide food, reduce poverty, and meet growing energy needs in the future. There are many on-going efforts to achieve this.[7]

## References

1. Adapted from: R. Wolfson, "Energy from Earth and Moon" in Energy, Environment, and Climate, 2nd ed., New York, NY: W.W. Norton & Company, 2012, ch. 8, pp. 204-224
2. GEODH. (August 13, 2015). Developing Geothermal District Heating In Europe [Online], Available: http://geodh.eu/wp-content/uploads/2012/07/GeoDH-Report-2014_web.pdf
3. Oregon Tech. (August 13, 2015). Geo-Heat Center [Online], Available: http://www.oit.edu/orec/geo-heat-center
4. R. Wolfson, "Energy from Earth and Moon" in Energy, Environment, and Climate, 2nd ed., New York, NY: W.W. Norton & Company, 2012, ch. 8, pp. 204-224
5. Geothermal Education Office 2005. Geothermal Energy Uses [Graphic]
6. National Energy Authority. (August 19, 2015). Greenhouses [Online], Available: http://www.nea.is/geothermal/direct-utilization/greenhouses/
7. Food and Agriculture Organization of the United Nations, Uses of geothermal energy in food and agriculture [PDF], Available: http://www.fao.org/3/a-i4233e.pdf