Combining cooling, heat, and power

Beacon is implementing a tri-generation energy conservation project at 53 State Street in Boston — producing electricity, hot water, and chilled water for the property. The system will allow the building to reduce the amount of energy (electricity and district steam) provided by local utility companies by 35% with a corresponding reduction in GHG emissions.

The central chiller plant is a chilled water storage system that operates at night to produce and store 40ºF (5ºC) chilled water in a 150,000-gallon storage system, for use during the day to meet building cooling requirements. This design allows the chilled water pumps, compressors, and controls to operate at a constant, most efficient energy consumption rather than the normal energy-inefficient process of load-following during the change in cooling demand throughout the business day.

With imported electric utility power produced off-peak, the utility’s GHG emissions are also at its lowest per kWh generated. Real-time utility-provided electric and district steam are measured in five-minute intervals at the property and monitored 24/7 to identify anomalies or unusual patterns in energy use or system operating hours, allowing building engineers to investigate and adjust operations as needed to minimize energy use while maintaining tenant comfort.

Energy-efficient elevators

The major renovation and modernization of the 14 building elevators included the installation of regenerative drives on all elevators, which has reduced elevator electricity use by 45%. Regenerative drives are designed to generate electricity when an elevator comes down full of people or when it is summoned from lower floors to upper floors with few occupants.