Packaged Hybrid CHP Plant

Client: Austin Energy; Department of Energy; Oak Ridge National Laboratory
Completion Date: 2006
Location: Austin, Texas


Burns & McDonnell provided turnkey installation of a packaged hybrid combined heat and power (CHP) energy plant for the Dell Children’s Medical Center of Central Texas. We helped secure $995,000 of Department of Energy cost share funding for this innovative packaged CHP plant. Austin Energy provided the balance of funding and to own and operate the hybrid CHP energy plant project.

The hybrid CHP system is designed to provide 100 percent of the hospital's energy requirements with the utility grid providing backup service to the on-site CHP generation system. In the event of a grid outage or disturbance, the energy plant will disconnect from the grid without any disruption of service to the hospital. It was the first hospital in Texas to be fully grid independent and the first hospital in the nation to use the efficiency provided by the CHP plant to achieve Leadership in Energy and Environmental Design (LEED) efficiency credits from the U.S. Green Building Council, earning Platinum certification.


  • Design
  • Construction


Burns & McDonnell utilized a Solar Turbines, state-of-the-art, Mercury 50 recuperated natural gas combustion turbine as the prime mover for the project. The Mercury 50 is capable of producing up to 4.5 megawatts of on-site generation at a simple heat rate efficiency of 38 percent and guaranteed NOx emissions of 5 ppm without catalyst. The exhaust from the combustion turbine is ducted through a bypass diverter valve to a heat recovery steam generator (HSRG) that produces up to 13,000 pounds per hour. The steam from the HSRG is used to provide process steam to the hospital for sterilization and enough steam to produce a nominal 1,000 tons of chilled water produced from a Trane two-stage absorption chiller.

Overall system efficiency of the CHP system is estimated to be greater than 75 percent. The project will utilize the output based emissions formula developed by the Texas Commission on Environmental Quality.

Burns & McDonnell provided all the design and construction services for the project. The plant was in full service by February 2007.


In addition to the CHP system, the hybrid energy plant will include the following modular components:

  • 1,500-ton electrical duplex centrifugal packaged chiller plant complete with cooling tower and condenser water pumps
  • 22,000 PPH natural gas fired stand-by packaged boiler
  • Primary and secondary chilled water pumps
  • 1,500-kW emergency diesel engine generator
  • 8,000-ton-hour chilled water storage tank and chemical treatment.