Drill, Baby, Drill! Geothermal Energy

Feb. 13, 2012

Geothermal energy is the only commercially available renewable energy that offers 100% uptime reliability.

Did you know that the U.S spends between 30 and 50 billion dollars every month on foreign oil?  I find that number to be HUGE and think 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 many of our resources on an environmentally toxic substance that also needs to be transported half way around the world.

If the goals are energy independence, environmentally friendlier and local jobs, some say the U.S should drill for domestic oil and other fossil fuel resources that are within U.S. borders.

In a recent interview I had with T.Boone Pickens, he mentioned that if we switched large trucks to natural gas instead of diesel we could reduce foreign oil dependency by 50%. I agree with him, but also think we should focus more on geothermal energy and 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 let me first explain the benefits of geothermal.

Geothermal Quick Facts
Geothermal energy is the only commercially available renewable energy that offers 100% uptime reliability. It uses extremely simple technology low operating maintenance costs and results in far fewer 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 U.S.-based resources to make kWhs, utility-scale geothermal steam generation plants are also eligible for 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. 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).

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 U.S. had over 600,000 GSHPs installed and operating by 2008, so the technology is proven and GSHPs are being installed by countries all over the world.

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, GSHPs provide long term jobs in the USA;
  • The ground loop requires fewer refrigerants, is quieter 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 it’s cloudy or calm;
  • 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.

The Economics of Ground Source Heat Pumps
I am surprised Ground Source Heat Pumps 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. 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.

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 it is cloudy or calm.). GSHPs provide 100% uptime. Because the ground loop has a long life and 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.

Let’s 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 x 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.

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.

Conclusion and Call to Action
Although GSHPs leverage a renewable energy resource, it does not currently allow the user to obtain RECs. I think we should change that.

Eric A. Woodroof, Ph.D., is the Chairman of the Board for the Certified Carbon Reduction Manager (CRM) program and he has been a board member of the Certified Energy Manager (CEM) Program since 1999. His clients include government agencies, airports, utilities, cities, universities and foreign governments. Private clients include IBM, Pepsi, GM, Verizon, Hertz, Visteon, JP Morgan-Chase, and Lockheed Martin.

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?

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? If the utilities could get RECs, maybe they would be able to subsidize GSHPs as a Demand Side Management strategy.

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.

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