Ball State University Constructing Country's Largest Geothermal Heat Pump System

The coal-fired plant used for heating and cooling Ball State University, in Muncie, Indiana is at the end of its useful life. Looking at building a new coal plant to today's standards revealed that costs are comparable to a geothermal heat pump plant. Estimates are about $66 million for the entire project. The University hopes to get $40 million from the legislature, originally approved for a new coal fired plant. The geothermal heating and cooling plant should save about $2 million dollars a year alone from eliminating the purchase of coal from BSU's budget. Implementing a carbon tax or carbon cap and trade system would serve to increase the financial attractiveness of the project for Ball State.

Considering the potential financial and environmental benefits of eliminating the coal burners, the geothermal heating and cooling plant was determined to be the most attractive alternative to building new coal fired burners. Drilling for the first phase began with a ceremony lead by Senator Richard Lugar in May 2009.

A statement by Thomas Kinghorn, Vice President of Business affairs and Treasurer of BSU suggested another potential economic upside for the BSU area in a recent AP article:

"We think we are positioned to take advantage of economic stimulus money," he said. If that happens, the project could be completed in five years. Without federal aid, completion could take 10 to 12 years."

In October of 2009 the U.S. Department of Energy Awarded Ball State with a $5 million grant for the project. There is no word yet on the additional funding.

Potential Positive environmental impacts

The positive environmental impacts include all those associated with the ending coal burning on campus. Heat pumps use electricity from the grid. This means a portion of the coal-generated pollutants is transferred to a coal fired electricity generator. Using natural gas for the affiliated hospital and for back up-in case of long periods of extreme cold-also creates pollutants, although fewer than coal based energy. Even considering this, the lead engineer, Jim Lowe, estimates a carbon footprint reduction by 40 to 50 percent.

This is how this estimate is arrived: Currently BSU produces 180,000 tons of carbon/year 88,000 tons of which are from the coal stacks, subtract 14,000 for electrical use of the heat pumps and you net 74,000-ton reduction. This equates to a 41% carbon foot print reduction.

Perhaps the most immediate environmental benefits of a completed geothermal heating and cooling plant system is eliminating the particulate matter, sulfur, mercury and other heavy metals from areas immediately downwind of the coal plant that sits just west of downtown Muncie.

Potential Negative Environmental Impacts

All the typical environmental problems such as erosion, nutrient loading into waterways, and difficulties in containing miscellaneous debris apply to constructing the geothermal heat pump system. Building of heat pump chillers and energy stations is another construction requirement

Placing sod back over the borehole area will return the land to its previous status. This can cause issues with overuse of chemicals and over fertilizing in order for the new sod to take. The boreholes are 400ft deep by 6-inch wide boreholes, which means the excavation of tons of soil, clay, limestone, etc. The project requires 4,100 of these boreholes. Long-term effects of borehole digging are highly dependent on the quality of the well construction.

The second phase of the project involves replacing old steam lines with 20 inch diameter hot water loops, buried 5 feet underground. This is likely to cause significant disruption to campus activity.

It's All in the Grout

The BSU system is "closed-loop "and will use only water with no additives. This eliminates a major concern of the EPA, and the Oak Ridge National Laboratory. According to an Illinois State Geological Survey 2004 report the vertical boreholes can "pose environmental threats." These threats would primarily involve improper grouting or failure of the grout. The BSU system uses a bentonite, sand mixture.

The Indiana department of Environmental Management defines bentonite as "A clay material composed predominantly of sodium montmorillonite that meets American Petroleum Institute specifications standard 13-A ."

A potential cause of such a failure it states is that the risk of bentonite drying is increased in areas of thick unsaturated zones. Drying can cause cracking. The deeper the boreholes are drilled the higher chance this will be a problem. The bond between grout, borehole and pipe is extremely important in keeping steady temperature. These impacts are lessened without the use of anti-freeze, however the study states there is still a risk of groundwater contamination by surface water and inter-aquifer flow interference.

The Illinois study concludes that bentonite grouts are better than neat cement grouts for vertical geothermal boreholes.

All Eyes on Ball State

As stated on BSU's website, as of March 2010, the geothermal system construction brought visits from universities across the country, delegations from Turkey, and media from Japan. The first phase of the project is reportedly on schedule. Much of the success of the project hinges on getting federal funds to complete the second phase. Will this be the environmental panacea and financial windfall that Ball State hopes? Alternatively, will it be an ambitious, yet financially burdened, environmental annoyance for the University and community?

Having seen and heard the plans directly from the project engineer, they seem relatively benign although 4,100; 400ft deep boreholes are hard to see as complrtely benign. For example, I don't know how the construction plans deal with the potential for compromising of ground water and the dangers of aquifers exchanging with one another.

As a Muncie resident, Ball State Alumni, and citizen of the world, my hope is that this project is a success. As a perpetual skeptic, I fear a failure.

References:

WTHR-AP Thomas Kinghorn Quote; http://www.wthr.com/Global/story.asp?S=9806552

The Environmental Effects of Ground-Source Heat Pumps- A Preliminary Overview. Illinois State Geological Survey; http://library.isgs.uiuc.edu/Pubs/pdfs/ofs/2004/ofs2004-02.pdf

Indiana Department of Environmental Management. (2009). Drilling Procedures and Monitoring Well Construction Guidelines. Indianapolis: IDEM.; http://www.in.gov/idem/nrpd_waste-0053.pdf