Geothermal Heating As Energy Source

Geothermal energy is produced by heat source from earth’s interior. These heat sources, few miles under our feet, could easily supply our current global energy demand for many years to come. According to International Energy Association, geothermal energy accounts for less than half-percent of global energy consumption now,

Active Geothermal Heat

Active geothermal energy is often associated with volcanic and seismically active regions. Active geothermal energy that produces steam for electric production is restricted to unique environments where magma reaches near the crust. Most of the active geothermal plants are located in volcanically active places, like Iceland, where the Earth’s outer crust is thin.

In recent years, hot dry rock and magma are the two forms of active geothermal energy being actively researched into. Both are able to provide thousands of megawatts for region as large as California.

Passive Geothermal Heat

Passive geothermal heating can be used anywhere. It works by using the heat of the earth to lower the amount of heating required in home or business. This is possible because the mass of the entire planet is kept at a constant 50F/20C or so.

All that’s required is a long length of pipe and excavation equipment known as geothermal heat pumps which provide both heating and cooling. In the “closed loop” configuration, this pipe snakes through the residential yard. “Open loop” system would typically run piping a couple hundred feet below the earth’s surface (or occasionally connect to a nearby body of water) where the temperature stays relatively constant throughout the year. Open loop system is less commonly used and cycle water from the bottom of a pond. This requires less pipe and digging, but may be subject to local environmental regulations.

In the close loop system, the other end of geothermal heat pump is attached to the foundation of the house. The pump circulates water and anti-freeze within the system to allow a lot of surface contact with subsoil. The heat is then radiated up through the house itself. In winter, since the ground is warmer than outside air, the heat pump expends less energy than conventional systems to heat up the building. During summer, since the ground is colder than outside air during summer, the pump also expends less energy than conventional systems to cool down the building.

Environmental Risk Of Geothermal Energy

Geothermal heat pump maintains high-efficiency all the time in virtually any climate. Indeed, at places with severe climates when it is very hot outside or very cold outside, or places where climate is characterized by high daily temperature swings, that is exactly when geothermal heat pumps are ideal.

Considered a green technology, geothermal does raise environmental concerns. In certain cases, steam extraction can allow other gases, like carbon dioxide (CO2), to escape. However, the amount of CO2 released per kilowatt-hour of electricity is only a few percent that of coal-fired power plants.

At certain locations with history of earthquakes, high-pressure water pumping is known to induce earthquakes ranging from 3.1 to 3.4 on the Richter scale.