Geothermal Heat Pumps are the Answer to Eliminating Electric Grid Spikes (like we saw in Texas)

It is wonderful to see the great publicity for geothermal technologies as a whole. While our associates in it direct use and enhanced geothermal systems are providing incredible baseload for energy infrastructure, it’s important to be able to manage the peak demand on the grid. The wide-spread power outages in Texas are an example a runaway peak demand in the heating season.
DID YOU KNOW?
Scientists projects that the U.S. geothermal energy will contribute to 10% of the country’s energy by 2050.
Ground Source Heat Pumps (GSHPs) are the key to managing demand on the electrical grid.

With all the air conditioning needed in the summertime, why would a winter time freeze cause the electrical grid to “spike” out of control as we saw in Texas? Most people know that air conditioning loads in the middle of August usually drive the greatest demand on the grid. However, electric heaters, often used to handle peak heating loads, can double or triple the peak in the wintertime.

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Electric Heat Compared to Heat Pump Energy Demand
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Electric Heat Compared to Heat Pump Energy Demand

Energy Facts:

  • 1 watt of electricity = 3.412 BTUs
  • I kW of heat consumed by an electric heater = 3,412 BTUs of heat
  • I kW of heat consumed by an electric Heat Pump = 17,060 BTUs of heat*
  • It takes 20% the kW to do the same heating with a heat pump *(@5.0COP)

As it gets colder outside, Air Source Heat Pumps lose efficiency. Geothermal Heat Pumps continue high efficiency operation regardless of outdoor temperature.

Cold temperatures can reduce efficiency of heat pumps, simply because it's hard to extract heat from outside air as it gets colder. The efficiency of air source heat pumps drops as it gets colder outside, just as the gas mileage efficiency of a car drops when it’s climbing a mountain road. Geothermal heat pumps are not subject to drastic temperature fluctuations, because they're coupled to the temperature in the shallow earth, which ranges between about 45 and 75 degrees in the US.

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AHSRAE Building Efficiency (Atlanta, GA)
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AHSRAE Building Efficiency

As you look at the efficiencies of heat pumps at the ASHRAE building in Atlanta, you can see that air source heat pumps are closer to geothermal heat pumps efficiency in the summertime, but in the winter time, when heating is needed most, the air source heat pumps are using much more electricity that geothermal by comparison. Geothermal clearly reduces peak electrical demand on the grid, eliminating problems like Texas experienced this winter.

Wintertime electrical peak load management is a well-known challenge as Northeastern states make the transition to total building-stock electrification. New York is eliminating combustion heating of all types in buildings (as is stipulated in the New York State’s Climate Leadership and Community Protection Act (CLCPA). As they make that transition, competent studies have proven that Geothermal Heat Pumps must play an integral role in Beneficial Electrification in order to manage peak electrical load in the coming decades.

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Benefits of Ground Source heat pumps for Beneficial Electrification
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Benefits of Ground Source heat pumps for Beneficial Electrification

Ontario completed a study at the end of 2020 that gives a 30 year roadmap to managing electrical grid spikes through the implementation of geothermal heat pumps. In the image, we can see the savings in reduction of fossil fuels, the cost for implementation of air source heat pumps, the cost for implementation of geothermal heat pumps, and at the far right is that Ontario will save half-a-trillion dollars on electrical grid modifications by choosing the geothermal solution. The reason is simple. Winter time peak loads are leveled through the implementation of geothermal heat pumps.

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Ground Source and Air Source Heat pump Comparison
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Ground Source and Air Source Heat pump Comparison

When I started in the GHP industry in 1990, I was asked by a reporter what the future held for the industry. I said that while excavation and drilling are required now for the systems, the day would come when geothermal pipelines would be worked into the infrastructure of communities. This is the place at which we find ourselves today.

Read more about geothermal grids in “New Contractor Opportunities with Geothermal Districts

Read more Beneficial Electrification in “The Integral Role of Geothermal Heat Pumps in Beneficial Electrification

About the Author: Jay Egg is a geothermal consultant, speaker, writer, and the owner of EggGeothermal. He has co-authored two textbooks on geothermal HVAC systems published by McGraw-Hill Professional. He can be reached at jayegg.geo@gmail.com.
©Egg Geo, LLC 2021

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Geothermal Heat Pump in Winter