In December 2004, the University became a member of the Chicago Climate Exchange and committed to a 4 percent reduction below 1998-2001 baseline emissions by 2006. A nearby wind farm supplies 60 percent of the Morris campus's needs. The Twin Cities campus has reduced consumption by 27 percent since 1991, despite the addition of energy-intensive research buildings. A steam plant burns waste wood and leftover oat hulls in its Circulating Fluidized Bed boiler, which cleanly burns almost any material. Finally, the utilities department interacts closely with academics on campus in evaluating the feasibility of projects involving renewable energy and energy efficiency, such as a solar array, the manufacture of hydrogen, and the utilization of methane gas from animal waste.