Geothermal Heat Pumps, Geoexchange systems, ground source energy, etc. all refer to the same thing: an HVAC system that utilizes the stores solar energy in the shallow areas of the soil or in a pond to alternatively heat or cool a building. Since the soil temperature remains relatively constant throughout the year in comparison with air temps, there is a differential in most parts of the US most of the year which can be extremely efficient for heating and cooling.
So of course, I had to know if there are any regional variations inside the US which made these systems more or less suitable for a given area. Mind you, this does not mean that you should skip the site suitability analysis should you be interested in purchasing a GHP: this map relies upon data at a 5km resolution…far too coarse for a local analysis.
Here’s how I created the map. I downloaded a global soil temperature database from the USDA Then I used global temperature means, highs, and lows, to produce a suitability map of the difference between these variables. What that shows is the areas in gray have soil temperatures that don’t differ too much, on average, with the air temperature, lowering the effectiveness of a GHP system.
Today, there are over 1,000,000 Geothermal Heat Pumps installed in the US, which reduces our crude oil consumption by some 21.5 million barrels annually.