Because the Earth maintains a constant temperature just 10 feet below the surface, systems that use shallow heat to control building temperatures above ground represent an easily accessible resource that can be deployed almost anywhere in the world. While the use of geothermal heat pumps and other forms of direct-use geothermal applications still make up a minuscule percentage of the overall heating and cooling market, growing electricity demand, rising energy prices, and increasing regulation around carbon emissions and energy efficiency will push demand higher over the next several years. Used on their own, geothermal heat pumps are capable of producing large reductions in energy use and peak demand in buildings. Used in conjunction with clean energy generation and whole-building efficiency – as in the recently announced partnership between Tendril and WaterFurnace International to offer a holistic solution combining home energy management with renewable energy – geothermal heat pumps can provide substantially increased benefits.
According to a recent report from Pike Research, geothermal heat pump sales will experience strong growth rates in the next several years, with annual unit shipments in the United States increasing from just fewer than 150,000 in 2011 to more than 326,000 units by 2017. The use of geothermal heat pumps integrated with energy management systems, such as programmable thermostats and utility demand response programs, will give homeowners and companies powerful new capabilities for adapting electricity loads in response to peak heating and cooling periods and for reducing energy costs.
"Direct-use geothermal applications, including geothermal heat pumps, face unique obstacles – primarily high installation costs," says senior analyst Mackinnon Lawrence. "But increased retrofit activity, a rebound in construction, and growing interest in the commercial and institutional sectors will drive strong growth through 2017 for geothermal heat pumps."
Led by the United States, China, and Sweden, 78 countries utilized geothermal for direct use applications in 2010. Geothermal heat pumps account for more than half of the direct use of geothermal worldwide, followed by bathing and swimming. Other applications include space heating, greenhouses, industrial processes, snow melting, and open ground heating. While cost and lack of consumer awareness remain primary obstacles to increased adoption, tax incentives and policies supporting building efficiency improvements will help overcome those barriers. Pike Research anticipates dramatic growth in the 2011-2017 timeframe, with the total worldwide capacity for geothermal direct use applications increasing by 179% during that period.