More than a decade ago, Alliant Energy began preparing to shut down Wisconsin Power & Light’s big Blackhawk generating station on the Rock River here. The company anticipated demolishing the enormous structure at considerable cost, but Scott Bierman had a better idea. Bierman, newly installed as president of neighboring Beloit College, proposed that the company spend its money making the site safe for reuse and then give it to the college, which would turn it into a student center.