GEOTHERMAL DIRECT
HEAT UTILIZATION
DISTRICT HEATING
GREENHOUSE HEATING
SWIMMING, BATHING BALNEOLOGY
FISH FARMING
GROUND SOURCE HEAT PUMP
(a) Categories of Capacity % for 2005 and
(b) (b) energy use in %, 2005
(Lund, Freeston and Boyd, 2005).
Summary of Worldwide Direct-Use Categories
(Lund, Freeston and Boyd, 2005).
Summary of Worldwide Direct-Use Categories
(Lund, Freeston and Boyd, 2005).
DISTRICT HEATING
Distribution of hydrothermal water from one or more wells
to several houses, buildings and blocks
DISTRICT HEATING
• It is the largest sector of geothermal
energy direct use in the world.
• It involves the distribution of heat (hot
water or steam) from a central location,
through a network of pipes to individual
houses or blocks of buildings.
• Geothermal Heating Systems are in
operation in at least 12 countries.
DISTRICT HEATING
EXAMPLE-1
DISTRICT HEATING
EXAMPLE-1
DISTRICT HEATING
EXAMPLE-2
DISTRICT HEATING
EXAMPLE-2
DISTRICT HEATING
EXAMPLE-3
DISTRICT HEATING
EXAMPLE-4
Degree-days = Number of days (Design room temperature-Daily mean temperature)
Demand at a given day
Load (%) 
100
Maximum demand
Average heat load over the year
Load factor
Peak heat load
GROUND SOURCE HEAT PUMP
Heat Pump Technology
• The Earth as a heat source and sink
• Heating in winter and cooling in summer
• In the USA and Europe
GROUND SOURCE HEAT PUMP
GHPs use the stable temperature of the ground;
• as a heat source 
• as a heat sink

to warm buildings in winter
to cool buildings in summer
• also for water heating by desuperheaters
GROUND SOURCE HEAT PUMP
The system includes three principal components:
• Geothermal earth connection subsystem
• Geothermal heat pump subsystem
• Geothermal heat distribution subsystem
GROUND SOURCE HEAT PUMP
Earth Connection Subsystem
• buried in the ground near the
building
• either vertical or horizontal
• circulates a fluid (water, or a
mixture of water and antifreeze)
GROUND SOURCE HEAT PUMP
A heat pump is a device which uses heat on a low
temperature level, and transfer the heat to a higher, useful
temperature level using an external driving force (mechanical
energy or high-temperature heat)
GROUND SOURCE HEAT PUMP
A heat pump is a device which uses heat on a low
temperature level, and transfer the heat to a higher, useful
temperature level using an external driving force (mechanical
energy or high-temperature heat)
Heat flows naturally from a higher to a lower temperature.
Heat pumps, however, are able to force the heat flow in the
other direction, using a relatively small amount of high quality
drive energy (electricity, fuel, or high-temperature waste
heat). Thus heat pumps can transfer heat from natural heat
sources in the surroundings, such as the air, ground or water,
or from man-made heat sources such as industrial or
domestic waste, to a building or an industrial application.
GROUND SOURCE HEAT PUMP
In order to transport heat from a heat source to a heat
sink, external energy is needed to drive the heat pump.
Because heat pumps consume less primary energy
than conventional heating systems, they are an
important technology for reducing gas emissions that
harm the environment, such as carbon dioxide (CO2),
sulphur dioxide (SO2) and nitrogen oxides (NOx).
GROUND SOURCE HEAT PUMP
Almost all heat pumps currently in operation are either
based
on a vapor compression,
or on an absorption cycle.
GROUND SOURCE HEAT PUMP
VAPOR COMPRESSION
GROUND SOURCE HEAT PUMP
VAPOR COMPRESSION