Pepco Central Plant Optimization: 5.37 Million kWh in Reported Savings

The challenge

The plant operated 24 hours a day, 365 days a year and had approximately 40,000 GPM of pumping capacity. Its equipment and controls had been modified over time and operated as a series of independent components. The project team determined that the strongest opportunity was to improve how the entire chilled-water production system was controlled rather than simply replace individual equipment.

Building a defensible baseline

For more than 10 months in 2012, the plant team and Tustin Energy Solutions collected and validated operating data. The work included reviewing prior electric bills and upgrading flow and temperature transmitters so the proposed improvements could be evaluated against a more accurate baseline.

The optimization approach

The project customized central plant optimization software to sequence the chilled-water plant as an integrated system. The onsite optimization server worked with the existing Allen-Bradley Rockwell plant control system, processing current and historical operating data and sending optimized strategies back to the controls.

Tustin also upgraded selected motor starters and critical instruments needed for the optimization strategy. Continuous feedback provided operators with greater visibility into plant performance and supported faster fault detection and operational adjustments.

Reported results

The optimization project was completed in 2013. The original case study reports total electric savings of 5,370,000 kWh for October 1, 2013 through July 31, 2014. It also reports a nearly 25% improvement in operating efficiency and a $500,000 rebate through the New Jersey SmartStart Buildings program.

These figures are historic results reported in the original project case study. They are not current operating data or guaranteed results for other central plants.