U.S. Dept. of Energy, Jan. 26, 2017, by Mike Mueller.

"Each year, more than 1.5 million people tour Alcatraz Island to visit its iconic prison. But, most people don’t realize that this 22-acre site, located in the middle of the San Francisco Bay, is also home to one of the nation’s largest microgrids. The island is equipped with a solar-diesel hybrid power system that most visitors probably won’t notice."