Sustainability of geothermal heat pumps
Call the graphic at left “The Blossom of Sustainability.” There’s nothing but benefits with the deployment of millions more geothermal heat pumps (GHPs). They separate society from the use of fossil fuels for occupied buildings. GHPs connect with thermal energy underground like a battery. That’s access to a sustainable renewable resource.
GHPs are long-lived. Some in residential use have exceeded 35 years before replacement. Their ground loop heat exchangers (GHEXs) are guaranteed for 50 years and those materials have been tested by a government agency for an equivalent life of over 200 years. This long term connection to the earth is completely renewable. What that means is this thermal resource will never run out, and it is forever free. Why wouldn’t we connect to such a clean and generous resource?
Zero Net Energy
Building owners reaching for carbonless Zero Net Energy will find GHPs provide the least expensive path to get there. Their GHP-equipped building would require the least renewable electricity generation such as solar PV or wind turbines to be installed on-site to consume no more energy in a year than it produces. Since GHPs magnify thermal energy from underground for heating, they require no imported fossil fuels to the building site. And although powered by electricity from the grid, that power is becoming increasingly renewable. California’s grid (not counting large scale hydro-electric) will be 33% renewable in 2020, and 50% by 2030. This continues a journey away from fossil fuels and toward a more efficient building stock. More electric cars and the use of hydrogen (from electrolyzed water) will make California’s grid a marvel by 2050.
In larger, commercial buildings, GHPs can reduce or eliminate the use of cooling towers which presently consume tens of millions of gallons of water per month in an arid state not yet free of a multi-year drought. With climate change on the minds of many and the greening of America’s populace underway, GHPs will do nothing but grow in popularity.