A Tale of Two Buildings

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A Tale of Two Buildings

• Geothermal Technologies Workshops
• Redwood Falls, MN Mar 17-18, 2008
• Sioux Falls, SD Mar 20-21, 2008
• Westminster, CO June 10-11, 2008
• Everett, WA Aug 11-12, 2008
• Guy Nelson, Team Leader
• Utility Geothermal Working Group

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• Palo Alto, CA
• Oklahoma City, OK

PROJECT RESULTS FROM A side by side Comparison
of a Ground Source Heat Pump System vs.
Conventional HVAC System between two identical
buildings.
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Testimony of a Building Owner

• We have always dealt with hassles short term.
• What is valued now is looking at the long term
  hassle of the decisions we make with a short term
  attitude.
• Brion McDonald, President, Universal Building
  Systems

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Oklahoma City Buildings

• Conventional 15,000 sq ft
• GHP 20,000 sq ft
• Conventional Roof Top VAV Building Built in 1987
• GHP Building Built in 1997
• 40 boreholes drilled 250 feet deep on 20 foot
  centers and 3/4 inch PE pipe
• 16 Ceiling Mounted Units

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Oklahoma City Buildings
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15,000 sq ft Building
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kW Demand Four Year Monthly Average
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OK BuildingskWh Electricity Consumption
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Load Factor (4 yr Monthly Average)
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2183 and 2185 Park Blvd Buildings

• Two Stories
• 10,000 sq ft each
• Built in the 1960s

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Palo Alto Buildings Energy Costs
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Hourly Load Curve Sample 08/22/2006
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GHP Non-Energy Benefits

• Space Requirements
• Noise
• Maintenance
• Ambient Conditions
• Bigger than a bread box

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GHP Capacity Benefits

• Assumption 1/2 kW per home peak capacity
  savings from a 3 ton GHP system
• Wholesale Capacity Cost - 10 per kW month
• 20 year system life
• Net Present Value ??????????

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GHP Capacity Benefits Net Present Value

• 3 - 1788
• 5 - 1400
• 7 - 1272

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US EPA Data

• A typical 3-ton (10.5kW) residential GHP system
  produces an average of about one pound less CO2
  per hour of use than a conventional system
• 100,000 homes converted to GHPs would reduce
  annual CO2 emissions by 125,000 tons per year
• 1.25 tons/yr per home
• http//www.nd.gov/dcs/energy/pubs/renewable/geoben
  .pdf

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Contact Information

• Guy Nelson, UGWG Team Leader
• 541-994-4670
• Gnelson181_at_aol.com