Charlevoix Public Library facilities manager Brian Wagner spoke to the Club about the challenges of energy efficiency in a complex building like the library.  They have gained some efficiency by controlling the temperature in the different zones in the building on the basis of the activity in the various areas. The primary energy savings, however, has come from the replacement of all incandescent light bulbs in the building with LED bulbs. Fifteen-hundred bulbs in 14 different fixtures have been replaced. The replacement project started in 2015. Wagner said the utility bill for the year was forty-five thousand dollars. It dropped to twenty-seven thousand dollars last year for a savings of over twelve thousand dollars. Of course, the LED bulbs were expensive, never-the-less, the cost of the bulbs will be recovered in three years. Out of all the LED bulbs installed only one has failed.