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  • Eric A. Woodroof, Ph.D., CEM, CRM, PCF

Drill Baby Drill... for GeoThermal Energy

Why I Support “Drill Baby Drill”

For Geothermal Energy

By Eric A. Woodroof, Ph.D., CEM, CRM

Buildings Magazine February 2012

Did you know that at this time, the USA spends between 30 and 50 Billion every month on foreign oil? I find that number to be HUGE and agree that we need to reduce that amount if we want to remain competitive, independent and environmentally friendly. It doesn’t make long-term economic sense to spend so much of our needed cash on an environmentally toxic substance that also needs to be transported half way around the world.

If the goals are to become more energy independent, environmentally friendly and create local jobs, some say the USA should drill for domestic oil and other fossil fuel resources that are within the US borders. In a recent interview I had with T.Boone Pickens, he mentioned that if we switched large trucks to use natural gas (instead of diesel) we could reduce that foreign oil dependency by 50%… I agree with him, but also think we should focus more on geothermal energy...and I call for a “drill baby drill” campaign that all political parties can endorse as it will save money and help our environment, while creating domestic jobs that would be difficult to outsource to other countries. To accomplish this requires a slight change in policy to remove some unfair barriers… but more on that later.

Quick Facts

Geothermal energy is the only commercially available renewable energy that offers 100% uptime reliability. It uses extremely simple technology, low operating and maintenance costs and results in far less emissions by using the earth’s thermal energy instead of fossil fuels. Geothermal energy represents a broad spectrum of applications, including utility scale power as well as solutions for buildings and homes. For example, utilities use “hot spots” in the earth’s crust to make steam and then drive a turbine to make electricity. In addition to using our US-based resources to make kWhs, utility-scale geothermal steam generation plants also get Renewable Energy Credits (RECs), just like solar and wind energy projects.

Where I want to focus your attention is on another example of geothermal energy- the Ground Source Heat Pump (GSHP) which uses the ground as a moderate temperature heat source during the winter and a heat sink during the summer. GSHPs are an example of renewable energy technology that is also distributed, (which reduces the strain on our electrical grid). According to the Department of Energy, the USA had over 600,000 GSHPs installed and operating by 2008… so the technology is proven and GSHPs are being installed by other countries all over the world. Although GSHPs leverage a renewable energy resource, it does not currently allow the user to obtain RECs... I think we should change that and the paragraphs below show why.

The Economics of Ground Source Heat Pumps

I am surprised they are not more popular…GSHPs reduce the kWhs required for air conditioning. When you also consider that when a utility promotes GSHP applications (for example- as a Demand-Side Management method), the utility will have reduced demand during peak periods, requiring less generation plants and less pollution. As our world’s overall energy consumption increases, we should be promoting GSHPs to help us satisfy our needs because a GSHP only costs about $.8 million/MW to build, as opposed to a new fossil-fueled power plant ~$2 million/MW.

I acknowledge that GSHPs do have higher installation costs to the building owner than a traditional air conditioner (air to air heat pump). The main reason is due to the infrastructure cost of drilling the GSHP boreholes and installing the ground heat exchanger. However, the ground loop will last more than 50 years, so perhaps utilities should treat this as “infrastructure” the same way that they evaluate transmission lines. If the utilities could get RECs, maybe they would be able to subsidize GSHPs as a Demand Side Management strategy. In addition, because these systems last 50+ years and we pay the operating costs every year, the life-cycle costs should be compared. When this is done in combination with the economic benefits to the utility- GSHPs are a “no brainer” and offer the lowest life cycle cost. Plus, they have shorter payback periods than other renewable technologies and do not require “back-up” infrastructure (wind and solar energy generators need “back-up” generation when its cloudy or calm winds). Thus, GSHPs provide 100% uptime. An additional benefit is that because the ground loop has a long life, is hidden and quiet… it is an asset to the building/home that should add value, the same way that a solar array on the roof does.

What is holding GSHPs back for massive scale support and installation by utilities? I think it is the lack of RECs and some other factors that could be easily remedied with some smarter legislation. Due to population and general trends… utilities need to prepare for higher demand, so why not get that energy from a renewable source at a reduced overall capital investment as well as reduced operating costs? Why shouldn’t the GSHPs get RECs if they are literally using the earth’s natural energy to avoid MW, just the same way that solar, wind and hydro technologies do?

Lets look at some sample numbers using these equations relating to Energy Efficiency Ratio “EER” and Coefficient of Performance “COP”.

EER = (COP * 3.412) = (BTU per hourmoved/wattsin).

Example: If you had a 5 ton air to air heat pump, we would be moving 5 * 12,000 BTU/hour, which equals 60,000 BTUs per hour. If the air-air Seasonal Energy Efficiency Ratio (SEER) is 10, that means we use ~6 kW every hour we run the air-air heat pump. In contrast, a GSHP would have a SEER of 20 during the Summer, which means you would only need ~3 kW. Thus, the GSHP reduces demand by ~3 kW, reducing emissions and helping the utility shave peak demand during the Summer. In the Winter, the SEER of the GSHP drops from 20 to 13.65 (COP = 4), meaning that the unit will draw 4.4 kW to move 60,000 BTU/hour. 4.4 kW equals about 15,000 BTU/hr of input energy, with the remaining 45,000 BTU/hr coming from the earth. Thus the total fuel/energy usage is still less than conventional sources (fossil fuels) because the GSHP gets ~75% of the energy from the earth (~45,000 BTU/hr), which avoids fuel that could be going into a natural gas fired heater/boiler. In addition, most utilities are not hitting their “kW peak load” during the Winter, thus GSHPs do help the utility level their kW load throughout the year, which is an effective demand side management function.

Benefits Summary for Ground Source Heat Pumps

  • Distributed energy source (no transmission lines needed);

  • Simple technology… has been applied since the dawn of human history;

  • Domestic energy resource and cannot be outsourced – thus GSHPs provide long term jobs in the USA;

  • The ground loop requires less refrigerants, is more quiet and lasts much longer than air-air heat exchangers or cooling towers.

  • The only renewable energy with 100% availability, (unlike solar and wind- which are variable and require additional generation assets for “back-up” when its cloudy or not windy);

  • Requires less capital than building fossil fueled power plants;

  • Reduced operating (as well as maintenance) costs over conventional systems;

  • Reduced emissions over conventional systems;

  • Requires less capital than building wind or solar generation (and lasts twice as long, with no equipment above ground);

  • Federal tax credits are available;

  • Helps utilities improve load factor (more constant loads);

  • Helps utilities avoid building more transmission lines;

  • Helps utilities establish new infrastructure that will provide 50 years of benefits, with practically zero maintenance costs.

Conclusion and Call for Action

With respect to Renewable Energy Credits, we should find a way to allow GSHPs to achieve them. Why does US policy grant RECs for Utility-Scale Geothermal (generating steam from the Earth’s “hot spots”), but not for GSHPs at the building level? Shouldn’t a BTU from the ground be able to become a REC in all designs?

The above reasons are why I support “drilling” for natural and environmentally friendly geothermal energy. If you would like to help get utilities to install geothermal systems as an alternative to more fossil fuel generation, let me know- I would like to hear your ideas on how we can get this done. I think the energy policy needs to be updated, and this would help us all over the long term.

Basically, during the Summer, it is easier to reject heat from the building to the ground (~60oF) versus the outside air (~80oF). The same concept is true in the Winter- easier to recover heat from the ground (~60oF) versus the outside air (~40oF).

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