Since the first water-tube boilers made over one hundred thirty years ago, central energy plants have provided a consolidated energy source for multiple building complexes. Central utility plants now include boilers, chillers, thermal storage, cogeneration equipment, electrical gear and monitoring, and energy management systems. The primary benefits of central utility plants, compared to smaller local systems, are reduced operating costs, better maintainability, less downtime, and easier servicing. The major disadvantage is first cost. more