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Geothermal Technology
Gary Myers “Gary the Energy Guy” Energy Use Specialist
Poudre Valley REA
Gary Myers aka “Gary the Energy Guy” Energy Use Specialist for Poudre Valley REA Personally performs up to 320 audits (including
geothermal) per year Regularly presents on this topic Professional designations include
• IGSHPA Certified in Loop Field Installation • Formerly Licensed Geothermal Installer by Colorado Department of
Water Resources • BPI Building Analyst Professional Certification • Energy Star trained in building performance • EAA Certified Environmental Inspector • NATE Certified in Heating & Air Conditioning • Licensed HVAC Specialized Contractor & Construction Supervisor
Know Your Trainer
Broad understanding of geothermal technology and ground source heat pumps, including: What it is How we use it How the technology works Installation considerations General system operation/maintenance
What You Will Learn
Geothermal Energy
Geothermal energy is energy that comes naturally from the heat of the earth:
Geo = Greek meaning “Earth” Therme = meaning “Heat”
What is Geothermal Energy
Map source: Wikipedia
Geothermal History
• In 1904, Prince Piero Conti, owner of the Larderello fields in central Italy, attached a generator to a natural steam driven engine. It was a small generator which only lit four light bulbs – the first of its kind.*
*Top-Alternative-Energy-Sources.com **Wikipedia.com
Geothermal History
– This experiment let to the installation of the worlds first geothermal power plant, in 1911, with a capacity of 250 kilowatts.*
– The Larderello fields now produce 10% of the worlds entire supply of geothermal electricity – 4,800 gigawatts hours per year – powering about 1 million Italian households.**
– This was the world’s only industrial producer of geothermal electricity until 1958, when New Zealand built a plant in Wairakei.*
*Top-Alternative-Energy-Sources.com **Wikipedia.com
Watt Measurements
– Watt = unit of power – Kilowatt = 1000 watts
• Average household typically uses 900 kilowatt hours of power per month or more.
– Megawatt = 1 million watts – Gigawatt = 1 billion watts
*Top-Alternative-Energy-Sources.com **Wikipedia.com
Direct/Natural Uses: Geothermal energy is very graphically
displayed in the form of geysers, hot springs, etc. Water from natural hot springs is often directly
used for hot spring pools, bathing, etc. • Places like:
– Glenwood Springs, CO – Idaho Springs, CO – Thermopolis, WY
Use of Geothermal Energy
Geothermal energy is also used by Power Plants:
Use of Geothermal Energy
U.S. Department of Energy, Idaho National Laboratory
Dry Steam: These were the first type of geothermal power generation plants built. They use steam from the geothermal reservoir as it comes from wells and route it directly through turbine/ generator units to produce energy. An example of a dry steam generation operation is at the Geysers Region in northern California.
Flash Steam: These are the most common type of geothermal power generation plants in operation today.
They use water at temperatures greater than 360oF that is pumped under high pressure to the generation equipment at the surface. Upon reaching the generation equipment, the pressure is suddenly reduced,
Use of Geothermal Energy
U.S. Department of Energy, Idaho National Laboratory
allowing some of the hot water to convert or “flash” into steam.
This steam is then used to power the turbine/generator units to produce electricity.
An example of an area using the flash steam operation is the CalEnergy Navy 1 power plant at the Cosco geothermal field.
Binary Cycle: These plants differ from the other systems because the water or steam from the geothermal reservoir never comes in contact with the turbine/generator. Instead, the geothermal reservoir is used to heat another “working fluid,” which is vaporized and used to turn the turbine/generator units. These systems can operate with lower temperature waters, by using working fluids that have an even lower
Use of Geothermal Energy
U.S. Department of Energy, Idaho National Laboratory
boiling point than water.
They produce no air emissions.
An example of an area using a binary cycle system is the Mammoth Pacific plants at the Casa Diablo geothermal field in California’s eastern Sierra Nevada.
Wikipedia says: Estimates of the electricity generating potential of geothermal
energy vary from 35 to 2000 gigawatts. Current worldwide installed capacity is 10,715 megawatts The largest capacity is in the US (3,086 MW), Philippines
and Indonesia Geothermal electricity generation is currently used in 24
countries. Geothermal heating is used in 70 countries.
Use of Geothermal Energy
Megawatt (MW) = 1 million watts Gigawatt (GW) = 1 billion watts
Krafla Geothermal Power Station - Iceland
• This plant alone has been operating at full power production of 60 mega watts of geothermal energy since 1999.
• Dry Steam turns the turbine, turbine turns the generator, etc. • This is one sample of the geothermal power plants in use powering the country of
Iceland. • The second largest geothermal power plant in the world is the Hellisheioi Power
Station in Hengill, Iceland, which puts out 213 mega watts of electricity.
Krafla Geothermal Power Station - Iceland
Photo Courtesy of Harry Kruekeberg
Krafla Geothermal Power Station - Iceland
Photo Courtesy of Harry Kruekeberg
Krafla Geothermal Power Station - Iceland
Photo Courtesy of Harry Kruekeberg
Geothermal Geysirs/Mudpots in Iceland
Photos Courtesy of Harry Kruekeberg
1) What does “Geothermal” mean? 2) Name one natural use of geothermal energy. 3) In what year and in what country was the first
geothermal power experiment done? 4) Name the three types of geothermal power plants. 5) Which of the three types of geothermal power plants
is most common? 6) How many countries currently use geothermal
electricity generation? 7) How many countries currently use geothermal
heating?
Group Exercise 1 Geothermal Energy
Geothermal Heat Pumps
Residential/Commercial Geothermal/Ground Source Heat Pumps (GSHP) - this is where we’ll focus. It all starts with the sun…
Use of Geothermal Energy
Air-to-Air (Most Typical)
Water-to-Air (Most Typical Geothermal)
Water-to-Water (Hydronic)
Split System (Dual Fuel or Add-On)
Combination (Hydronic + Forced Air)
DX Geothermal (Refrigeration in GHX)
Types of Heat Pumps
Heat pumps operate like refrigeration units Refrigerators/freezers, air conditioners, ice
machines, etc. are actually all heat pumps. Refrigeration leverages and multiplies input
energy, creating additional BTUs. When heat pumps are connected to the earth,
performance can be increased to as much as five times the incoming electrical energy.
Heat Pumps
1. Thermostat calls for heating/cooling 2. Pumping module & compressor
activate 3. Water flows thru inner jacket of
coaxial heat exchanger, while refrigerant flows around the outer jacket
4. Blower motor draws air over air coil 5. Air coil cools or warms incoming air 6. The cooled or heated air is delivered
to the home
GSHP – How It Works
Systems can be single-speed or two-speed, referring to the compressor and fan speeds. Two-speed systems increase efficiency.
Systems can be forced-air type (with ductwork delivery system) or hot-water type (with hot water piping delivery system).
Heat Pumps
2900+ sf home 4-Ton (48,000 btu) Split system Gas furnace backup
In My Own Home
The first regular heat pump was patented in 1912.
In October 1948, a Life magazine article highlights the “Fireless Furnace”
In the 1980’s, closed-loop geothermal systems began being installed in Oklahoma
The oldest water-source heat pump is located in Winnipeg, Canada, and has been running since 1954!
…geothermal technology is not new
Tried and True Technology
Benefits
You pay for 1 unit of electricity
You get 3 units of free energy from the
earth
You end up with 4 units of heat
GeoComfort
Always available – 24/7/365 Home grown and available nearly everywhere Green alternative – an average residential geo
system is the “green” equivalent to planting nearly a half acre of trees
Can increase perceived home value in the eyes of potential buyers
Can include options such as radiant heating/cooling, hot water generation, pools, etc.
Benefits
GSHPs are recognized by the EPA as: “the leading space conditioning technology in all
locations…[considering] operating performance, annualized cost, environmental impact & attractiveness to utilities as a DSM [demand side management] measure”
Initial costs are higher, but: Systems last many, many years Payback is significant and continues over the life
of the system – well exceeding the initial cost
Benefits
If Geo has even 5% of the HVAC market (5 million+ systems installed)… Fossil fuel savings would be more than 30 million MMBtu,
or more than 6 billion Kwh, annually
Electricity demand would be reduced by 2 million KW
More than 1.2 million metric tons of carbon and approx. 4.5 million metric tons of CO2 would be reduced annually.
The environment equivalent of nearly 1 million cars removed from the road, 290 million trees planted, etc.
Benefits
No outdoor equipment Fewer components / less maintenance Longer life expectancy No fuels, fumes or flu pipes
Benefits
Solar and wind energy each require an expensive storage system, so the amount of energy they can produce/provide is limited by the amount of storage available
…with geothermal, the earth is providing an almost unlimited storage capacity.
Benefits
1) It all starts with what? 2) Name two types of geothermal heat pumps. 3) Name one household appliance that operates like a
heat pump. 4) When was the first heat pump patented? 5) How many units of delivered energy do you get with
one unit of electricity when using geothermal heat pump technology?
6) Aside from energy savings, name three benefits of geothermal heat pumps.
7) Where is the energy produced by the geothermal heat pump system stored?
Group Exercise 2 Heat Pumps
Hot tub heating Pool heating Porch/step snowmelt Sidewalk snowmelt Driveway snowmelt Etc.
Additional Uses for Geothermal Heat Pumps
Code Requirements: The code requirements for each city, county, state can differ.
Proper Sizing: Everything starts with a Manual J heating and cooling calculation.
Adequate Delivery System: Interior airflow is an important component.
Proper Loop Field Design: This isn’t just putting pipes in the ground - loop design and sizing are critical.
Conductivity: What’s in the earth is important too.
Installation
Local Code Requirements Larimer County Planning & Building Code requires: • ACCA Manual J Calculation
Package be submitted with plans for new residences and additions with new furnace.
• Heat loss calculations from software choices, such as Wrightsoft, Nitec and Elite are required.
Calculations should assume: • 6368 Degree Days Heating • 479 Degree Days Cooling
Effective July 31, 2011 www.co.,larimer.co.us/buildings/res_guide_book.,pdf
State Requirements All geothermal loop fields installed in the State of Colorado must have a well permit registered with the Division of Water Resources (DWR).
As stated in a DWR document titled: Geothermal Development in Colorado
Impacts to Existing Water Uses and Frequently Asked Questions
“The State Engineer, who is also the director of the Colorado Division of Water Resources, is the regulatory authority for the purposes of permitting and administering the use of geothermal resource…” “…this means that before any party can construct a geothermal well, that party needs to obtain a permit to construct a well from the State Engineer.”
www.water.state.co.us
Everything starts with a Manual J heating and cooling calculation, which considers things like: Structure location/exposure
Overall structure size
Windows: size, quantity, exposure, coverings, etc.
Insulation values/overhangs
Ceiling heights
Etc.
Installation - Sizing
If improperly sized: System cycles too frequently/“never shuts off”
Moisture is not adequately removed
Coil temperatures are too high (on average)
Equipment life is reduced
Efficiency is reduced, which increases the energy use
Loop field integrity is threatened
Comfort issues appear
Installation - Sizing
The delivery system is the ductwork, register and return air configuration within the structure
Ductwork must be installed properly Size and location
Sealed and insulated
Registers and return air grilles must be installed properly Size and location
Velocity and airflow / unobstructed
Installation – Delivery System
Three options – each depends on the location of the structure: Vertical Horizontal Pond/Lake
Installation – Loop Field Design
GeoComfort
GeoComfort
GeoComfort
Different equipment is required for each of the different types of installations Vertical – Well driller Horizontal – Backhoe/excavator Pond/Lake – Boat/Slim Jim
Installation – Loop Field Design
Typically SDR11 – high density polyethylene pipe specifically designed for geothermal applications Typically ¾” to 1” pipe for
residential installations
Piping contents includes Antifreeze and water mixture
specifically suited for this purpose – environmentally safe
Loop Field Piping
Thermal Conductivity is the property of a materials ability to conduct heat.
Thermal Diffusivity is the ratio of thermal conductivity to heat capacity – measure of how fast thermal disturb-ance can be felt from one location to another. High diffusivity typically means less thermal storage capability with faster change in temperatures over time. Substances with a high thermal diffusivity rapidly adjust
their temperature to that of their surroundings, because…
• they conduct heat quickly, and • generally do not require much energy from their
surroundings to reach thermal equalibrium
Installation – Loop Field Location
Wikipedia www.grti.com
Conductivity What’s in the earth is important too Granite has a high thermal conductivity Drill logs for nearby drilling can be helpful to
determine what’s in the earth
Installation – Loop Field Location
1) What code requirements must be followed when installing a geothermal system?
2) What is the key to proper sizing of the system? 3) Give two reasons why is proper system sizing
important. 4) Name two important factors in the installation of a
structure’s ductwork/delivery system. 5) What are the three types of loop fields for Geothermal
Heat Pumps. 6) What kind of loop field requires a geothermal well
driller? 7) Name two important factors in the quality of any loop
field.
Group Exercise 3 Heat Pump Installations
Geothermal Heat Pump Case Studies
Prior to GSHP Installation: 2200+ Gallons of Propane
Annually $0.90/Gallon = $1,980/yr Cooling Cost: $500+/yr Annual Heating/Cooling
Cost: $2,480 Average per month $207
Case Study - Retrofit
After GSHP Installation: 6-Ton Geothermal System Heating (Oct 98 - April 99) Cost: $718 Cooling (May 99- Aug 99) Cost: $196 Total Annual Heating/Cooling Cost $914 Average per month $83
25 yr. old, 2-story ranch with walkout basement:
Courtesy of GeoComfort Geothermal Systems www.geocomfort.com
Heating (Nov 99 - April 00) Cost: $267 Cooling (May 00 - Aug 00) Cost: $112 Avg. per month: $32
Case Study – New Construction 4500 sf, 2-story ranch with walkout basement –
6-Ton w/5 zones:
Courtesy of GeoComfort Geothermal Systems www.geocomfort.com
Heating (Oct 01 - March 02) Cost: $255 Cooling (May 01 - Sept 02) Cost: 217 Avg. per month: $40
Case Study – New Construction
Courtesy of GeoComfort Geothermal Systems www.geocomfort.com
3200 sf, 2-story ranch – 3-Ton GSHP System:
Case Study – New Construction
Courtesy of GeoComfort Geothermal Systems www.geocomfort.com
2-story ranch – 4 Ton GSHP System:
Heating (Oct 01 - March 02) Cost: $255 Cooling (May 01 - Sept 02) Cost: 217 Avg. per month: $40
Rebates, tax incentives, etc., can help lower installation costs (PVREA Member Rebate = $400/ton) Incentives and Rebates vary from year to year,
state to state and utility to utility. Some utilities provide loop field leasing
options to their customers. The utility pays for the initial loop field installation,
then leases it back to the customer at a monthly fee (Delta/Montrose).
Incentives
Why would utilities promote?
At a meeting with the Governor’s Energy Office that I attended in August, I learned that:
• More than 100,000 geothermal heat pumps were installed across the nation in 2011 alone.
• The U.S. Department of Energy (DOE) has set a goal that “1 million” Geothermal units be installed “annually” in the U.S. by the year 2017.
• Utilities are encouraged to participate in this effort.
Incentives
Why would utilities promote?
Increased efficiency, means utilities may be able to add customers without adding demand, which may mean fewer substations, etc.
Peak demand is more manageable, when more efficient systems are in place.
Member satisfaction is improved as comfort is improved (without increased utility expense).
Incentives
Why would utilities promote? Increased efficiency, means utilities may be able to
add customers without adding demand, which may mean fewer substations, etc.
Peak demand is more manageable, when more efficient systems are in place.
Reduces need for utilities to buy energy on the open market at a higher cost.
Member satisfaction is improved as comfort is improved (without increased utility expense).
Incentives
Largest University Increased efficiency, means utilities may be able to
add customers without adding demand, which may mean fewer substations, etc.
Statue of Liberty Peak demand is more manageable, when more
efficient systems are in place.
Ski Resorts Member satisfaction is improved as comfort is
improved (without increased utility expense).
Commercial Applications
Slinky Design 53 heat pumps attached
Commercial Applications
Reality Photos
Reality Photos - Headers
Reality Photos - Manifold
Reality Photos – The Vault
Reality Photos – Smart Pumps
Reality Photos – Control System
Reality Photos – Commissioning
U.S. Department of Energy www1.eere.energy.gov/geothermal
International Ground Source Heat Pump Association (IGSHPA) www.igshpa.com
Colorado Division of Water Resources http://water.state.co.us
Resources
Questions?
Gary Myers Energy Use Specialist
Poudre Valley REA 970.282.6464
