Water Savings

The stated goal for water usage was to save 10 million gallons with the installation of the geothermal system. First-year water savings totaled over one-and-a-half times the projected goal at 18.7 million gallons, with nearly half of that amount resulting from shutting down the old power plant.  The blue portions of the stacked bar graph below represent water usage directly affected by the geothermal project.  This usage came from two areas on campus: the old power plant, and rooftop cooling towers associated with the conventional chiller units now augmented by the new geothermal system.  Differences shown in the red and green portions were omitted from water savings calculations in order to determine the geothermal system's stand-alone impact on water use, which is calculated to be approximately 16.5 million gallons. Another estimated 2.2 million gallons of collective water savings were found throughout the buildings serviced on the geothermal loop, and attributed to repair of hidden leaks in the water mains replaced during construction (not shown on graph).  "Balance of Water Use" represents the difference shown between the usage recorded by Rolla Municipal Utilities on the 15th of each month and the in-house meter readings done by S&T maintenance staff on the final day of each month.  The geothermal system is constantly undergoing efficiency evaluation during the course of its operational service life.  The data collected is then used to fine-tune system parameters and maximize future water savings over time.  

Graph of campus water usage referenced in accompanying text

 

Energy Savings

Before the geothermal system was in place, the power plant provided steam to the campus for most heating and some cooling needs. Additionally, the plant also supplied a small percentage of campus power.  Once the geothermal system was operational in May of 2014, the power plant's coal and wood-fired boilers were shut down and decommissioned.

The geothermal system provides heating and cooling to the campus through hot and chilled water distribution systems.  All electricity used on campus is now delivered by the local municipal utility.

Due to the efficiency differences between combusting fuel to produce and distribute steam versus utilizing heat recovery chillers connected to geothermal well fields, the anticipated savings for the project was a reduction of 50% of energy consumed on the campus.  During the first year of operation, the geothermal system reduced total energy use by 57% relative to 2009 and 60% relative to 2010.  As the graph below clearly indicates, campus energy demand has peaked in January for the last seven fiscal years.  In the two years following the installation of the geothermal system, the average January kBTU consumption fell to less than half of pre-geothermal levels, and total average monthly consumption has shrunk by 56%.  2016 saw a 1% increase in campus energy efficiency due to ongoing analysis and refinement of the system. 

Graph mentioned in the accompanying text.

 

 

 

Emission Reductions

smokestack image

The air we all breathe is arguably the most precious resource on the planet.  Since the dawn of the industrial age, humanity has pushed ever more forcefully on the ability of the Earth to keep its atmosphere clean.  While the new geothermal system itself may be buried far and away from the air we all breathe, its impact on our carbon footprint is nothing less than profound.  In 2009, a campus-wide energy audit discovered the S&T power plant alone was responsible for the release of over 32,000 tons of carbon dioxide, an atmospheric burden which was instantly eliminated upon completion of the geothermal project.  Although this is an impressive number, it does not represent the actual savings gained through the geothermal project.  Due to shutting down the power plant, the campus increased its demand for energy supplied by other sources.  Net reduction of carbon dioxide emissions was found to be 25,017 tons following the system's first year of operation.  With all three stated goals of the geothermal project exceeded, the endeavor can be easily described as a resounding success.