Sustainability | Renewable Energy

GREEN Energy from the Earth

Image result for Geothermal power in Iceland
Svartsengi geothermal power plant, Iceland

Large scale geothermal power

Geothermal power plants use the energy created by natural sources of heat generated in the earth, particularly around active tectonic plates which create frequent seismic activity. Naturally occurring steam from the earth runs generators in a geothermal power plant. Large-scale geothermal power plants are found in Iceland, the United States, and Italy, among a few other countries. In Reykjavik, Iceland, where geothermal energy sources are found everywhere, geothermal energy is generated from areas around volcanoes, geysers, and hot springs; for several geothermal power plants throughout Iceland.

The  Larderello Geothermal Energy plant in Italy is the world's oldest geothermal power plant, first generating a sizable quantity of energy over 100 years ago. After many renovations over the last 105 years; Larderello Geothermal Energy is a complex of 34 geothermal plants now generating around 800 MW, producing around 2% of Italy’s energy mix, and powering around 1 million Italian homes. The largest geothermal power plant project in the world is a complex of 22 plants called The Geysers in California at over 1.5 GW.

Oldest geothermal plant in the world
Larderello Geothermal Energy plant in Italy


Geothermal energy can also be produced through the use of man-made technology. Enhanced Geothermal Systems (EGS), also known as engineered geothermal systems (hot dry rock geothermal), refers to a variety of engineering techniques used to artificially create hydrothermal resources (underground steam and hot water) that can be used to generate electricity. EGS is typically constructed into a large-scale operation when it is developed and implemented.

Geothermal Heat Pumps

Geothermal energy has a micro application along with its macro counterpart. This micro form is primarily in the form of geothermal heat pumps. Geothermal heat pumps regulate a building's temperature by the use of ground-source heating and cooling. Across the world, geothermal heat pumps are gaining popularity as a top choice for a clean and efficient renewable energy technology to heat and cool a building to augment/ replace traditional HVAC (heating ventilation and air conditioning) units.

A geothermal heat pump is an electrically powered unit that transfers energy to your property from heat energy underground (as opposed to an air source heat pump, which also heats and cools your property, but uses heat from above ground air). In the majority of locations worldwide, the temperature under the surface of the earth is consistently 10-15°C, producing a constant source of heat energy. The geothermal heat pump uses this constant heat source by piping in heat energy to provide a home with HVAC  and water heating. A geothermal heat pump thereby acts as central heating and/ or a system which can replace/ augment traditional HVAC systems.

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a geothermal heat pump uses the heat generated below the earth's surface as HVAC for a property

Geothermal heat pump systems significantly reduce fossil fuel use and greenhouse gas emissions, by reducing energy demands and consumption; and by replacing energy-intensive, fossil fuel-based systems with renewable energy systems. Geothermal heat pumps are very environmentally friendly, generating no emissions or pollution. In addition to geothermal heat pumps, clean energy sources of heating and cooling for your property, which are also energy efficient, are electric air source heat pumps (a clean energy source, as they work from electricity- but not a renewable energy source, just an electric source).

Geothermal heat pumps can produce results that are more than double the energy efficiency and cost efficiency of even the best fossil fuel-based HVAC technologies. This is another renewable energy based technology that significantly reduces energy bills, as well as saving energy. The use of geothermal heat pumps has routinely cut heating bills in half while operating with significantly greater efficiency than traditional HVAC systems.

Please also see: renewable energy overview

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