DIRECT-USE GEOTHERMAL –
FOCUS ON GREENHOUSE HEATING
James C. Witcher
Masson Geothermal Greenhouse, Radium Springs, New Mexico Williamson, NREL

OTHER USES ?
 Desalination
 Copper/Gold
LINDAL
DIAGRAM
NMBGMR, Earth Matters,
Summer, 2006, modified from
Geothermal Education Office

Red
Convective
Systems
Light Blue
Deep Conductive
Systems in Tertiary
Basins
Dark Blue
Deep Conductive
Systems in
Paleozoic and
Mesozoic Basins

GEOPHYSICAL LOG
BOTTOM HOLE TEMPERATURES

EXAMPLE OF CONVECTIVE
GEOTHERMAL REGIME
• Annual temperature
wave near surface
• Conductive gradient
above water table or
geothermal system
• Temperature “rollover”
in outflow plume
Rincon SLH 1

Example Resource and Exploration Model  Structure controls
 Aquifers(reservoirs)
 Properties
 Aquitards (caps)
 Hydrogeology
 Flowpath
 Heat Sources
 Thermal Sweep
Witcher

Geology modified from Seager (1975)

HYDROGEOLOGIC WINDOW
PROBLEMS
• Production temperature
decreases
• Injection wells not
taking full production
Witcher
SOLUTIONS
• Site production wells further from injection wells
• Add production from the deep parent reservoir
• Eliminate open hole completions for injection
wells and add liners
• Use larger diameter injection wells

• Isothermal in
Paleozoic carbonate
reservoir
• Conductive
across Tertiary
Palm Park Aquitard

ADVANTAGES
1) Significant savings in energy cost.
2) Energy costs are stable and predictable over the long haul.
Masson Geothermal Greenhouse, Radium
Springs, New Mexico
NMSU

DRAWBACKS
1) Up front capital costs.
2) Approach unfamiliar.
3) Acceptance of risk.
4) Can require more effort.
New Mexico State University,
Southwest Technology Development
Institute, geothermal greenhouse
NMSU

• SOUND BUSINESS
PLAN
• EXPERT GROWER
AND GREENHOUSE
MANAGER
• MARKETS TO SELL
PRODUCT
Masson Geothermal Greenhouse,
Radium Springs, New Mexico
NMSU

CO-LOCATION OF
1) Suitable land.
2) Geothermal
resource.
3) Fresh water
source.
4) Labor force.
5) Sunshine.
6) Market for
crop.
NMSU

GEOTHERMAL GREENHOUSE
HEATING
• CENTRAL HOT WATER
SYSTEM
• GEOTHERMAL WELLS
AND HEAT EXCHANGERS
 REPLACES
CONVENTIONAL FOSSIL
FUEL BOILER
Geothermal Heating Distribution
Manifold, Masson Geothermal
Greenhouse, Radium Springs,
New Mexico
Williamson, NREL

The primary object of geothermal green housing is to grow the best quality crop profitably with energy savings.
NMSU Masson Geothermal Greenhouse,
Radium Springs, New Mexico

• Geothermal production wells.
• Geothermal pump.
• Geothermal pipe line.
• Heat exchangers.
• Geothermal injection well.
• Proper sizing and materials selection.
New Mexico State University, Southwest
Technology Development Institute, geothermal greenhouse
NMSU

• Prevent scaling and corrosion
• Isolate geothermal fluids
from heating equipment and
environment
• Plate and frame heat exchangers
are very efficient
NMSU
Haslego and Polley (2002)

Drilling Masson Federal 36, Radium
Springs, New Mexico, Masson
Geothermal Greenhouse
Witcher
• LARGE DIAMETER
• DESIGNED TO HOST
PUMP EQUIPMENT
• DRILLED TO MINIMIZE
FORMATION
DAMAGE
• COST HIGHLY
VARIABLE ($75 TO
$400/ft)

WHERE TO HEAT?
1) Floor heating and soil heating.
2) Bench top heating.
3) Overhead heating.
4) Perimeter heating.
5) Crop irrigation water.
NMSU Masson Geothermal Greenhouse, Radium
Springs, New Mexico

PERIMETER, OVERHEAD, AND
BENCH HEATING WITH FINNED
TUBING
FINNED PIPE
Prevents cold spots.
Can be used in first stage heating.
Use with other heating such and floor, overhead and benchtop heating.
NMSU

• Fan-coil heating unit.
• Unobtrusive installation.
• Efficient.
• Assists with snow melt.
NMSU

RADIANT FLOOR HEATING
Construction of new 2-acre greenhouse range with radiant floor heating, Masson
Geothermal Greenhouse,
Williamson, NREL
Radium Springs, New Mexico
ADVANTAGES
• Provides thermal mass and stabilized heating system
• Decreases geothermal well production
• Places uniform heat at plant roots
• Allows for flood irrigation

FLOOD IRRIGATION
Williamson, NREL
Completed 2-acre greenhouse range with radiant floor heating and flood irrigation, Masson
Geothermal Greenhouse,
Radium Springs, New Mexico
PROBLEM
• Irrigation water is treated with reverse osmosis (RO) to remove undesirable minerals and nutrients are added
(important cost factors)
SOLUTION
• Flood irrigation conserves water by recycling excess water and nutrients and decreases costs and disposal needs

HOT WATER STORAGE
Hot water storage tank,
Masson Geothermal Greenhouse,
Radium Springs, New Mexico
PROBLEMS
• Slow heating response to rapid temperature/weather changes
• Continue optimal heating if one of the well pumps fails on a winter night
SOLUTIONS
• Use large 167,000 gallon insulated hot water storage tank to buffer heating system
• Use radiant floor heating
Williamson, NREL

• PERMITTING
• RESOURCE OWNERSHIP
• WATER RIGHTS
Alligator aquaculture, Mosca, Colorado
• ENGINEERING FEASIBILITY
• BUSINESS AND MARKETING PLAN
• FINANCING
• RESOURCE ASSESSMENT AND RESERVOIR
CONFIRMATION
• PRODUCTION/INJECTION WELLS
•
RESOURCE MANAGEMENT PLAN
• ENVIRONMENT AND PUBLIC RELATIONS
NREL

USDOE
Soda Lake, Nevada, 26.1 MWe Binary Power Plant
Witcher
Witcher

BarberNichols

• GEOTHERMAL
POWER
CASH FLOW
• $0.085 kW/hr cost
(subsidized)
• 1 or 2 employees
• 8,760 hrs/yr
• $744,600 per MW/yr gross receipts
• No energy savings compared to natural gas or coal power
• GEOTHERMAL
GREENHOUSE
CASH FLOW
• Annual sales $850,000 to $425,000 per acre
• 8 employees per acre
• $35,000/yr energy savings per acre in southern New Mexico
• 4,200 MMbtu/yr at
$1.50/MMbtu
levelized 20yr
Natural gas
$11.00/MMbtu (boiler inefficiency included)