Efficient Energy

In our last homework assignment I found an article about UNT and the way they supply power to the campus. A majority of the energy currently used in from coal power. But now there is a nationwide organization working with other colleges and universities to try and reduce the amount of coal energy to zero. Coal is a fossil fuel which when burned releases toxic and harmful contaminants into the air. So now the organization is working with President Rawlins to help create and use different ways of supplying energy to UNT. When walking to class one day I even met a supporter of this movement and she was handing out fliers or taking surveys or something. While I continued to talk to her, she asked if I used the gym on campus. I told her I do. The she continued to tell me that our gym uses a unique way of supplying energy to create electricity to the gym. When people ride bikes or use similar machines, they are hooked up to a generator or something which creates the electricity needed for the building. I didn't know that and think it's pretty cool. What are some other ideas you may have to create efficient energy for UNT or anything else that need electricity?