Geothermal energy is thermal energy stored in the Earth that humans can extract, process and then use.  Geothermal energy is cost effective, reliable, and sustainable, but has historically been limited to areas near tectonic plate boundaries.  Recent technological advances have expanded the range and size of viable resources, especially for applications such as home heating.  Geothermal wells release greenhouse gases trapped in the earth, but these emissions are much lower than those of fossil fuels.

Allerton Park was able to install a geothermal energy system at the Evergreen Lodge, with funding from the Student Sustainability Committee (SSC) and the Department of Commerce and Economic Opportunity (DCEO), as part of the American Recovery and Reinvestment Act (ARRA).  There are opportunities for future installations of geothermal energy, when funding allows.

Wind Turbine Generators (WTG) on South Farms was originally proposed by Students for Environmental Concerns (SECS) in 2003, and led to the formation of the the Student Sustainability Committee (SSC) in 2005. The project proposed the installation of up to three wind turbines on campus to show the university's intent to invest in renewable energy. Even though the project was approved in 2005, it never took off and was eventually cancelled by the Chancellor in 2008.

A renewable portfolio standard, passed in 2007, has supported wind power in Illinois, which required 10% renewable energy from electric companies in 2010 and 25% by 2025. At the end of 2011, Illinois had 2743 megawatts (MW) of wind power installed. Illinois has the potential for installing up to 10,000 MW of wind generation capacity; in 2009, it ranked sixth among states for installed wind turbine capacity.

The 24-panel, gravity fed solar-thermal system on the roof of the ARC preheats domestic cold water prior to its introduction into the steam-powered heat exchanger for domestic hot water, which significantly reduces steam usage for domestic hot water during normal operating periods. There are three main areas of hot water usage (domestic, pool, and air heating), but domestic (i.e. showers and sinks) represents the most pressing need and efficient use of solar technology.

This feasibility study considered the potential placement of a Photovoltaic array on the roof of Krannert Center for the Performing Arts (KCPA). The Study was conducted in two phases. A construction budget of five hundred eighty-five thousand dollars ($585,000), excluding contingencies, was proposed by the Student Sustainability Committee.

The goal of the ECE (Electrical and Computer Engineering Building project is to achieve Platinum LEED standards and be net zero for outside energy consumption.  To meet that goal, engineers have proposed the use of solar panels atop the ECE building to offset the building’s energy consumption. Complexities of building design have resulted in the building being unable to support a sufficient number of solar arrays to generate the energy required to offset the building’s energy consumption.

The Electrical and Computer Engineering (ECE) Building includes Solar Panels on its roof. The panels provide about 11% of the building's energy needs each year. The infrastructure for connecting these panels to the building electric supply was included in the original design and construction costs for the full building, while the solar panels themselves were funded separately. 

The Business Instructional Facility was the first production rooftop solar PV array installed on a campus building.  In 2009, 168 panels were installed above the auditorium, with 190 Watts per panel and a total system size of 32 kW. The installed panels were SANYO HIP-190/200BA3 PV Modules, with UniRac SolarMount PV Mounting Hardware, Xantrex PV20208 Inverters, and Xantrex CB-12H20-3R Combiner Boxes. 

One potential method for acheiving the 2015 iCAP goal for on-campus solar is to retrofit existing campus buildings with rooftop solar.  The amount of sun shine on each roof, the viability of the building itself, and the funding mechanisms all need to be reviewed and resolved for this idea to be implemented.  The viability for each building includes approval from the Architectural Review Committee, agreement of the building occupant facility leaders, and structural and electrical viability for the building.  As of 2016, the financial payback for solar photovoltaics is not strong enough to ea