Architect-On-Duty architect-on-duty.com                                      Last Update 20061209

Geothermal Energy Systems (GES):

The Heat Pump takes advantage of "stored" solar energy by using the largest solar collector, the earth and its atmosphere, but is not restricted to using energy provided by direct solar radiation.

1)    GES systems are tapping largest stored solar energy source, body mass of our planet Earth (5,972,000,000,000,000,000,000,000 kg, ).

2)    Stafford Haensli Architects Inc. and our team has considerable experience with the design and applications of Geothermal Energy Systems (GES) or also called Ground Source Energy Systems, as main source of heating and cooling for commercial and institutional buildings.  Our team in association with "Ground Heat Systems International" strongly believe that the only safe heat exchange media capable to transfer the geothermal energy safely and effectively is WATER.  Our team has successfully completed several projects using water as the heat exchange media.  First project was commissioned in 1983 (Father Michael McGivney Secondary School in Markham, Ontario, 15,000.0 sq.m.).  All our systems are located in Canada (Ontario), with exposure to extreme cold temperatures during winter (-32C/-25F), and hot temperatures in the summer (+37C/+98.5F).  All systems are designed to heat and cool on demand.

3)    Our GES utilize water based heat pumps as key energy transfer equipment.  Heat pumps use electricity to extract energy from the energy transfer media (water). It is very important to understand that heat pumps do not use electricity to heat or cool the heat transfer medium (water), they extract the geothermal energy from the media (water).   Comparing energy use of standard heating and cooling systems used in buildings with GES systems indicates reductions in  energy consumption up to 75%.  One of our projects is independently monitored by one of our clients since 1983 and compiled data is available (please contact Lubomir Dzamba; lubomir.dzamba@architect-on-duty.com )

4)    GES - Extract the energy from water which circulates in the ground loop "energy wells" which are up to 122.0m deep (400').  Earth temperature at depth of 1.5m (5') is constant at approximately +8.0C (+46.0F) providing continuous supply of +8.0C (+46.0F) water.  Temperature difference Dt between freezing point of 0.0C (+32.0F) and +8.0C (+46.0F) is the energy extracted by the system, and used for heating or cooling of buildings.  Energy is extracted from the water via Water Based Heat Pump (WBHP).  Please note that systems are kept away from reaching 0.00C (+32.0F) so the water does not freeze up the system.

5)    Drilling of the vertical wells (Energy Wells or EW) for GES is specialized activity requiring experience and specialized equipment.  Drilling produces sludge like compound expelled from EW by the underground water and air injected into the drill bit.  Depending on the sub-grade rock type, the sludge may look like cement (shale), and therefore cause concern when spilled over the sidewalks, parking lots or roads.  The sludge has no ability to solidify, and it is easily removed from any surfaces by stream of water (garden hose).  The sludge should be prevented from directly entering any catch basins.  This can be achieved through the use of sediment dams or filtering dams.  Usually if the distance of catch basin is greater than 20m (70') from the drilling area this results in full separation (sedimentation) of  the heavier rock particles from water.  This separated sediment can be gathered later and disposed of as clean fill. 

 6)    Excluding the electricity to run the pumps, GES do not require burning of any fuel to extract the energy from the heat sink of the ground mass, therefore are not contributing to greenhouse gasses pollution.  Despite the fact that GES systems are quite efficient the payback period for the installation of the necessary equipment is on large projects (size over 60,000 sq.ft.) approximately 6 years (considering Canadian energy prices of 2002, 1kWh=$0.08, 1,000 c.f. of natural gas=28.3m3=$10.00).  Payback on smaller projects (single family houses) is estimated at 10-12 years.  However we can easily state that due to continuous rise of energy prices and technological advances in methods of extracting heat from liquid media will make this technology quite feasible for mass use in single family housing projects in second half of this decade (2005-2010), with payback period of 5-6 years.  Ballpark estimating of energy efficiency can be done by simple rule of 1:3 and 1:4.  During winter GES system will use $1.00 of electricity to generate equivalent of $3.00 in heat if generated by burning natural gas in high-efficiency furnace.  During summer GES system will use $1.00 of electricity to generate equivalent of $4.00 in cooling if generated by standard air-conditioning unit using electricity (this rule is proportionate to your local energy costs).

7)    Good sources of information can be found at following links: Energy Efficiency and Renewable Energy Network (EREN)