Presented by John Cole East Coast Account Rep. for RENEWABLE ENERGY Construction Automotive Industry
WHAT IS GEOTHERMAL AND HOW DOES IT WORK? REHAU 10.09.08 - Page 2
WHAT IS GEOTHERMAL ENERGY? Definition - Geo (Earth) thermal (heat) - Geothermal = heat exchange with the Earth - Geoexchange is gaining popularity - This term describes the entire system from ground loops to circulation pumps to the heat pump Where does the energy come from? - The Earth's core - Radioactive decay - The sun - Insolation impacts the outer crust REHAU 10.09.08 - Page 3
THE TEMPERATURE OF THE EARTH - Heat is continually supplied to the ground in the form of solar energy - Approximately 46% of the sun s energy is absorbed by the Earth (U.S. Dept. of Energy) - At a depth of approximately 15 feet the ground temperature remains fairly constant, with a mean annual Earth temperature of 42-77 F (depending on location) REHAU 10.09.08 - Page 4
MEAN ANNUAL EARTH TEMPERATURES EARTH S UNIQUE THERMAL INSULATION CAPABILITY REHAU 10.09.08 - Page 5
STABLE EARTH TEMPERATURE Ground Temperature The greater the depth, the more stable the ground temperature is Thermal lag, the seasonal effect, is more dramatic at shallow depths Example from a specific U.S. region Line 1 = February Line 2 = May Line 3 = November Line 4 = August Depth (ft) 66 50 33 16 0 Temperature ( F) 32 41 50 59 68 REHAU 10.09.08 - Page 6
HOW DOES IT WORK 0 F 70 F Insulating layer of earth A Geothermal System absorbs heat from the ground in winter & transfers the heat into the building 40-60 F REHAU 10.09.08 - Page 7
HOW DOES IT WORK 100 F 70 F Insulating layer of earth and cools the building in summer by rejecting heat to the ground 40-60 F REHAU 10.09.08 - Page 8
HOW DOES IT WORK? Principles A geothermal system gets the majority of its energy from the earth s latent heat A geothermal system pumps heat from one location to another 25% (1 unit of purchased electricity) 100% (4 units of heat to the building) 75% (3 units of free energy from the Earth) REHAU 10.09.08 - Page 9
HOW DOES IT WORK? - Ground loop (Earth): A sealed and pressurized closed loop pipe system circulates water/antifreeze solution below the Earth s surface - Refrigerant loop (Heat pump): A sealed and pressurized loop transfers the thermal energy in the heat pump through the compressor - Air loop (Air distribution): Distributes conditioned air to the building - Desuperheater loop (optional): For Domestic Hot Water REHAU 10.09.08 - Page 10
SUMMARY Ground Source Heat Pumps are: - Electrically powered systems that tap the stored energy of the greatest solar collector in existence: the Earth. These systems use the Earth's relatively constant temperature to provide heating, cooling, and hot water for homes and commercial buildings. * - Efficient, cost effective and environmentally-friendly heating/cooling systems *International Ground Source Heat Pump Association (IGSHPA) REHAU 10.09.08 - Page 11
WHAT BENEFITS DO GEOTHERMAL SYSTEMS OFFER YOU? REHAU 10.09.08 - Page 12
PRIMARY BENEFITS: ENERGY SAVINGS Heating 30% - 70% energy savings Cooling 20% - 50% energy savings REHAU 10.09.08 - Page 13
PRIMARY BENEFITS: ENERGY SAVINGS COP = COEFFICIENT OF PERFORMANCE Energy Source Electrical Resistance Propane Fuel Oil Natural Gas Geothermal COP 1.00 0.88 0.85 0.93 4.0 COP = Total energy produced by system / energy purchased or COP = What you got / what you bought REHAU 10.09.08 - Page 14
PRIMARY BENEFITS: ENERGY SAVINGS SAMPLE COSTS - VIRGINIA, LATE 2008 Energy Source Electrical Resistance Cost / Energy Unit (Efficiency) $0.08/kWh (100%) Net Cost (USD) / 1,000,000 BTU $22.75 Propane $2.75/Gal (88%) $34.00 Fuel Oil $2.50/Gal (85%) $21.00 Natural Gas $1.30/Therm (93%) $14.00 Geothermal $0.08/kWh @ 4.0 COP (400%) $5.69 Conversions: 1 kw = 3413 BTU; 1 Gal Propane = 92,000 BTU; 1 Gal No. 2 = 140,000 BTU; 1 Therm = 100,000 BTU REHAU 10.09.08 - Page 15
BENEFITS LEAD TO GOVERNMENT INCENTIVES Geothermal benefits have helped government officials to understand the positive impact that these systems have on energy independence, the environment and national security. Federal tax incentives as part of the 2009 American Recovery and Reinvestment Act - An uncapped 30% residential tax credit is available for each residential GHP installation - A 10% federal grant is available for each commercial installation - Incentives last through 2016 All 50 states have some kind of GHP Incentive Visit the Database of State Incentives for Renewables and Efficiency (www.dsireusa.org) website for a list REHAU 10.09.08 - Page 16
BENEFITS LEAD TO GOVERNMENT INCENTIVES Geothermal benefits have helped government officials to understand the positive impact that these systems have on energy independence, the environment and national security. 29 states have financial incentives - Sales tax and property tax exemptions, income tax credits and grants 31 states have regulatory incentives - Green public building requirements 29 states have utility incentives - Loans and rebates - Mandatory Renewable Portfolio Standards (RPS) and Energy Performance Standards (EPS) - Voluntary Demand Side Management (DSM) Programs REHAU 10.09.08 - Page 17
COST COMPARISON: GEOTHERMAL VS. CONVENTIONAL TECHNOLOGY Location: Baltimore, MD Heating Load: 84,000 BTU Cooling Load: 36,000 BTU Conventional Heating Source High efficiency natural gas furnace Forced air distribution $11,000 Conventional Cooling Source Central air conditioning Additional $4,000 Geothermal System House Size: 3,500 ft 2 7-ton* ground source heat pump Rough total system cost of $30,000 (vs. $15,000) Typically monthly savings on utilities outweighs increased monthly mortgage payment *1 ton = 12,000 BTU/hour REHAU 10.09.08 - Page 18
COMPARISON: GEOTHERMAL VS. CONVENTIONAL SYSTEM Data based on Baltimore, MD design parameters using Ground Loop Design Software REHAU 10.09.08 - Page 19
COMPARISON: GEOEXCHANGE VS. CONVENTIONAL SYSTEM REHAU 10.09.08 - Page 20
SUMMARY: BENEFITS OF GROUND SOURCE HEAT PUMP TECHNOLOGY - Reduced operating costs - Reduced emissions - Low maintenance - Simplicity - Efficiency - Water heating - No auxiliary heat - Low power demand - Packaged equipment - Environmentally friendly REHAU 10.09.08 - Page 21
GEOTHERMAL DESIGN BASIC SYSTEM COMPONENTS AND DESIGN CONSIDERATIONS REHAU 10.09.08 - Page 22
BASIC SYSTEM COMPONENTS GROUND SOURCE HEAT PUMP WATER-TO-AIR - Most common heat pump type where heating and cooling are required - Works with forced air distribution REHAU 10.09.08 - Page 23
BASIC SYSTEM COMPONENTS GROUND SOURCE HEAT PUMP WATER-TO-WATER - For heating and cooling - Residential or commercial - Works ideally with hydronic (water) distribution - Radiant heating/cooling - Snow and ice melting - Also works with forced air distribution using hydronic fan coils REHAU 10.09.08 - Page 24
BASIC SYSTEM COMPONENTS MANIFOLD, CIRCULATION PUMP, FLOW CENTER REHAU 10.09.08 - Page 25
BASIC SYSTEM COMPONENTS GROUND LOOP PIPES POLYETHYLENE PIPES WITH FUSED U-BEND - Fusion-welded single x U-bend - HDPE Material - 3/4, 1, 1 1/4 pipes - CTS or IPS dimensions - Fused joints, in field or factory - Two pipes in a bore hole (one loop) REHAU 10.09.08 - Page 26
BASIC SYSTEM COMPONENTS GROUND LOOP PIPES CROSS-LINKED POLYETHYLENE (PEXa) - Continuous Single or Double U-bend - PEXa material - 3/4 or 1 sizes - CTS SDR9 dimensions - No joints in the well or loop - Up to four pipes in a bore hole (two loops) REHAU 10.09.08 - Page 27
GEOTHERMAL APPLICATIONS CONFIGURATIONS: CLOSED LOOP Energy Pile Storage Vertical Wells Horizontal Fields REHAU 10.09.08 - Page 28
GEOTHERMAL APPLICATIONS VERTICAL BOREHOLES - Commonly used in commercial applications - Used in residential applications where space is limited - Approximately 150-200 ft. of borehole per ton of energy required - This varies across the country with different soil types, water tables, etc. - Typical sizing is 1.5 tones per 300 feet well depth REHAU 10.09.08 - Page 29
GEOTHERMAL APPLICATIONS HORIZONTAL FIELD - Commonly used in residential applications - Sometimes used in commercial applications where space allows - Approximately 300-400 ft. of trench (600-800 ft. of pipe) per ton of energy required - Variations in trench layout acceptable Field system alternate variations REHAU 10.09.08 - Page 30
GEOTHERMAL APPLICATIONS HORIZONTAL DIRECTIONAL DRILLING (HDD) - Commonly used in residential applications - Sometimes used in commercial applications where space allows - Approximately 200-300 ft. of trench (400-600 ft. of pipe) per ton of energy required REHAU 10.09.08 - Page 31
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