What is it?
Which Bucket Does it Belong?
|Geothermal heating and cooling has been suffering from an identity crisis. There has been considerable effort and discussion to categorize geothermal into one bucket or another. Is it renewable, is it solar, or is it simply a effient way to provide heating and cooling? Each one of these buckets, by itself, is woefully inadequate to describe the essence of the geothermal technology. There is plenty of justification to assign geothermal to each of these buckets.|
|We would suggest that geothermal deserves it's own barrell, one that reflects the renewable nature of harvesting the solar energy stored in the ground in an extremely efficient manner.
How is This Efficent Harveting of the Renewable Solar Energy Accomplished?There are many methods to "connect" to the earth to absorb or reject heat. To describe each of these is beyond the scope of this section, but the terms such as closed loop, open loop, standing column, pond loop, direct exchange, hybrid systems, horizontal, vertical and many more would be helpful in doing additional research, but for now, let's focus on the fact that accross New York State the average ground temperature will be somewhere between 45 and 55 degrees Fahrenheit. These temeratures are maintained by the local climate which is ultimately derived from the sun.
To harvest this heat for the purpose of heating any number of thermal loads, such as space heating, domestic water heating, heating a swimming pool, etc. we simply create a cold spot in the earth, then through the unstoppable mechanism of heat transfer the heat will flow from the warmer eath into the cold spot. The cold spot will be maintained at a cold temperature by circulating a cold fluid through pipes buried in the ground, this fluid will warm up and return to a heat pump where it is cooled again.
The Magic of a Heat PumpThe ability to extract heat from a cold fluid and keep you comfortable in your home does indeed seem like magic. The same sense of mystery occurred when ice boxes were replaced with refrigerators. Replacing fossil fuel burning furnaces and boilers with geothermal heat pumps will have a similar impact to our quality of life. In addition to eliminating combustion in your home you will be reducing carbon dioxide emissions and contributing to creating a more sustainable future.