HOW HOME GEOTHERMAL WORKS

Geothermal energy – does it make sense? Sounds like a good topic for Science Café

David Brooks, January 19, 2015 (The Telegraph)

“…[G]eothermal energy in New Hampshire, more accurately described as ground-source heat pumps…has been around for decades but has gained more prominence as part of the alternative-energy mix…At its simplest, geothermal pumps water underground, where temperature remains around 50 degrees, then brings it back above ground at that temperature and uses it to cool or heat buildings…Heat, of course, naturally moves from warm to cold. A heat pump uses a relatively small amount of energy to reverse the process, pulling heat out of a low-temperature area and moving it into a higher temperature area – from a ‘heat source,’ like the ground, into a ‘heat sink,’ like your home…The system involves a fluid with a very low boiling point, on the verge of being a gas at room temperature. The head pump shifts this substance back and forth between the liquid and gas states with compression, which makes it release or absorb large amounts of energy, due to the physics of phase change. That energy is how cold water can heat a house…” click here for more

click to enlarge

Tweet