Friday, September 18, 2015

GEOTHERMAL

Wikipedia -
"Geothermal power (from the Greek roots geo, meaning earth, and thermos, meaning heat) is power extracted from heat stored in the earth. This geothermal energy originates from the original formation of the planet, from radioactive decay of minerals, and from solar energy absorbed at the surface. It has been used for bathing since Paleolithic  times and for space heating since ancient Roman times, but is now better known for generating electricity. Worldwide, geothermal plants have the capacity to generate about 10 gigawatts of electricity as of 2007, and in practice supply 0.3% of global electricity demand. An additional 28 gigawatts of direct geothermal heating capacity is installed for district heating, space heating, spas, industrial processes, desalination and agricultural applications."


Geothermal power is cost effective, reliable, sustainable, and environmentally friendly, but has historically been limited to areas near tectonic plate boundaries. Recent technological advances have dramatically expanded the range and size of viable resources, especially for applications such as home heating, opening a potential for widespread exploitation. Geothermal wells release greenhouse gases trapped deep within the earth, but these emissions are much lower per energy unit than those of fossil fuels. As a result, geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels.

The Earth's geothermal resources are theoretically more than adequate to supply humanity's energy needs, but only a very small fraction of it may be profitably exploited. Drilling and exploration for deep resources costs tens of millions of dollars, and success is not guaranteed. Forecasts for the future penetration of geothermal power depend on assumptions about technology growth, the price of energy, subsidies, and interest rates"



Questions:

What is a ground source heat pump?

Ground source heat pumps (GSHPs) are electrically powered systems that use the earth’s fairly constant temperature to provide heating, cooling, and hot water for homes and buildings.

How do ground source heat pumps work?

Ground source heat pumps have closed loops that are be installed horizontally, vertically, or in a pond or lake.

The surrounding land area and  types of soil and rock at the site will help determine the most economical and efficient choice (system type) for the ground loop installation

An antifreeze solution is circulated through plastic pipes buried beneath the ground for closed loop systems. The fluid gathers heat from the earth and circulates it through the system and into the building.

During the summer, the system reverses itself and pulls heat from the structure and places it in the ground. This process creates free hot water in the summer and and produces a considerable savings on hot water in the winter.