Replacement of conventional natural gas fired boilers that have reached the end of their useful life with a skid-mounted, natural gas engine-driven combined heat and power (CHP) unit with integrated high-efficiency hot water boilers (referred to herein as Dalkia Aegis CHP with integrated high-efficiency hot water boilers and controls [CHP+]) provides cost-effective and reliable electricity and thermal energy delivery, as well as electricity and thermal energy resiliency.

This project will validate that it is technically and financially advantageous for the Department of Defense to implement CHP+ electricity and thermal energy resiliency solutions when replacing aging boilers in buildings with year-round thermal loads. Johnson Controls will remove a failed boiler and install the CHP+ system sized to reliably and efficiently meet the thermal load of the 525th Military Intelligence barracks complex at Fort Bragg, NC. The project team will integrate the CHP+ and new meters to the existing Fort Bragg Metasys Utility Management Control System (UMCS) for detailed performance monitoring, and provide maintenance and repair services during the duration of the study. The metered and trended data collected will verify CHP+ system energy input, energy output, performance, loading, runtime, and reduction in purchased utilities.

Technology Description

The Dalkia Aegis CHP+ integrates proven engine-driven CHP technology and high-efficiency packaged hot water boilers into a customizable and scalable hybrid skid-mounted unit. The combination of these technologies into an integrated system makes it possible to add efficient and reliable electricity and thermal energy generation to facilities when replacing conventional natural gas or propane fired hot water boilers.

The CHP+ package is composed of three connected skids with a combined total size of 14' long x 4.5' wide x 6.5' tall. One skid supports the engine-driven CHP, another provides the foundation for two modular hot water boilers, and the final skid supports the plumbing and controls. The comprehensive skid design takes advantage of economies of scale, provides cohesiveness across the three components, and reduces system footprint. The CHP and boilers share an integrated control system that communicates with Building Management System and UMCS systems via Modbus/Building Automation Controls Network protocol. The CHP+ will be integrated to the Fort Bragg UMCS using a Local Operating Network gateway.


The community building within the barrack complex contains an assembly area, operations area, laundry, showers, and restrooms. Use of the CHP+ system to safely, efficiently, and reliably meet the electricity and thermal energy needs of this building supports mission readiness by providing a shelter-in-place and troop assembly location during times of grid failure. The detailed metering and monitoring program planned for the 12-month performance testing period after installation of the CHP+ will monitor system performance, quantify energy-efficiency and energy savings, and illustrate the financial benefit of the CHP+ versus continued use of conventional natural gas fired boilers.

The reduction in purchased utility costs for the barracks complex is expected to be sufficient to fund the additional cost of installing the CHP+ (including the benefit of providing energy resilience) versus the cost of a like-for-like boiler replacement in as little as 12-years of operation.