Geothermal heat pumps continue to gain popularity as an alternative energy source.  This energy technology doesn’t come without uncertainties though.  In fact, as ENR recently described it, there are significant problems with the geothermal industry:  “[M]any of these systems are not performing as touted, especially cleverly hyped geothermal heating systems that are plagued with inflated savings claims and deficient designs.”

The article goes on to describe three primary problems with the geothermal industry:

  • “Their performance often is only superficially studied by equipment insiders whose main interest is selling more systems. As a result, the construction industry lacks a trusted set of independently audited best practices for design, installation and maintenance. This issue is becoming increasingly important as engineers scale up geothermal systems for larger buildings.”
  • “In particular, the coefficient of performance (COP) rating for a heat pump usually does not take into account the efficiency of the entire system. During design and installation, many variables can creep into that equation, such as the amount of electricity needed to pump water through piping loops, heat escaped through poorly built ductwork and seasonal imbalances in how much heat is dumped or pumped out of the ground. These all can compromise the COP and extend the payback time for systems.”
  • “Industry promoters working for owners, architects, engineers and contractors have done a poor job of educating consumers on the benefits and drawbacks of geothermal HVAC. There are large variations in average ground temperatures by region, but geothermal advocates would have potential customers believe ground temperature is a constant 55°F.”

ENR’s concerns about geothermal energy go to a larger point: owners and contractors should avoid promises of energy savings.  Unless you are a performance contractor, there are too many variables during operations and maintenance that impact actual energy use.

What are your experiences with the risks and rewards of geothermal heat pumps?

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More Straight Talk and Training Needed to Expand Geothermal (ENR)