Below we list the most promising technologies for use on our campus, around which the consultation groups have been formed.  Because wind and nuclear energy will be more effectively purchased from off campus, these technologies are not included in this section.

Geothermal heating and cooling

As it appears that it would be difficult to directly and entirely replace our existing steam production system with a carbon-free equivalent, we must examine the electrification of our thermal energy production system.  One very promising technology for this involves the use of geothermal heat pumps. Geothermal energy is thermal energy stored in the earth that humans can extract, process and then use, which is cost effective, reliable, and sustainable.

As an example of what can be accomplished with current technology, we consider Ball State University, which commissioned a large-scale district geothermal heating and cooling system in 2012. When completed, this system is expected to reduce emission of air pollutants by 85,000 tons and save Ball State University $2.2 million/year in operating costs. It uses large heat pump chillers to simultaneously produce chilled and hot water. The system has a design coefficient of performance of 3.8 for heating and 2.9 for cooling, meaning that for each unit of electric energy consumed 6.7 units of heat are moved.   Ball State University is at almost the same latitude as our university, so similar systems could be evaluated for use on this campus. A district geothermal system would reduce the use of fossil fuels on campus, but would increase the campus average demand for electricity .  The amount of GHG emissions associated with heating and cooling would then depend on the source of the electricity to run the geothermal system.  By generating renewable electricity on campus or purchasing renewable energy from off campus, we could greatly reduce our GHG emissions both in the short and the long term.  

An additional attraction of geothermal is the use of a hot water distribution system.  A study of the benefits of a possible transition from steam to hot water thermal distribution was recommended by the 2010 iCAP, which suggested that this transition, either central or distributed, can yield considerable energy savings.

Air-source heat pumps

About ten percent of campus buildings are heated by steam but cooled by window air conditioners.  If these were replaced by air-source heat pumps, each room could be both heated and cooled by the same unit.  The required capacity of the heat pumps could be reduced by a deep retrofit of the building, including replacing the windows with high quality double pane windows, reducing the size of oversized windows, and adding insulation to the interior or exterior of poorly insulated walls.  Rooms could be conditioned only when occupied, producing further energy savings.  In a new building or an additional, there would be no need for ductwork to distribute the cooled air which would lead to cost savings.  As with geothermal technology, the amount of GHG emissions associated with heating and cooling these buildings could be reduced by generating or purchasing renewable electricity.

Biomass

Biomass can replace coal for direct combustion, or replace natural gas if it is first used to create syngas through gasification or biogas through anaerobic digestion.  In 2013, the University of Missouri commissioned a 100% biomass-fueled boiler in their combined cooling, heat, and power plant, initially utilizing waste wood as the primary feedstock.  Eastern Illinois University installed a gasifier in 2011, but it is not yet working reliably.  These example projects highlight two necessary conditions for the success of biomass: establishing a sustainable supply chain and utilizing a reliable technology.

Due to the large acreage required to grow enough biomass to meet campus energy demands, some portion of the biomass would need to come from off campus.  This could be in the form of dedicated energy crops or agricultural waste.  One should take into consideration the energy cost of growing, harvesting, processing, and transporting the biomass.  While burning the biomass is carbon neutral if it is regrown, the growing, harvesting, processing, and transporting steps release greenhouse gases if they involve fossil fuels or certain fertilizers.  On the other hand, the growth of perennial biomass crops such as miscanthus leads to an increase in the amount of carbon stored in the soil; this sequestration of carbon in the soil may more than offset the emissions from biomass processing.  As a result, the entire life cycle of biomass growth, harvesting, processing, and combustion may result in a net removal of carbon dioxide from the atmosphere.  Additionally, when comparing biomass to fossil fuels and other renewables, many people ignore the energy cost of collecting, processing, and transporting the coal, natural gas or solar/wind energy; these figures should be considered in both cases (biomass and fossil fuel) or in neither when evaluating the use of biomass fuel.

Solar Photovoltaics and Solar Thermal

Solar energy is a proven technology that has become more cost-effective in recent years.  There are some existing installations of solar photovoltaics and solar thermal on campus now, and some installations currently in the implementation process.  A consultation group worked to identify the best locations for installation of additional solar on campus and to encourage funding of those installations. 

Wind energy

Wind energy is the highest renewable currently used on campus (as of FY17), through an off-campus Power Purchase Agreement for approximately 25,000 MWh/year.  For on-campus wind, rooftop wind generators and utility-scale wind turbine generators are two hopeful development options. Wind-turbines could potentially be installed on top of a building roof, and the Students for Environmental Concerns (SECS) proposed three utility-scale Wind Turbine Generators (WTG) on South Farms in 2003. The project planned the installation of up to three large wind turbines on campus to showcase the university's intent to invest in renewable energy. Unfortunately, after several setbacks including community pushback and low return-on-investment, this project was cancelled in 2011.