The University made headlines on Earth Day when it became one of the largest purchasers of renewable energy credits in higher education, committing to 40 megawatts, or 20 percent of its electricity usage, of wind power. A cogeneration plant in Chicago supplies 85 percent of the school's energy needs and the University has launched a feasibility study of building an additional plant in Evanston. A comprehensive Energy Star plan covers equipment purchases and a professional illumination consultant was hired to evaluate the potential for de-lamping on campus and switching older, inefficient bulbs to more efficient models.