Cogeneration

Cogeneration (also known as combined heat and power, CHP) is the use of a heat engine or a power station to simultaneously generate both electricity and useful heat.

Arizona State University Cogeneration Plant

APS Energy Services entered into an agreement with ASU to design, construct, operate and maintain a $45 million Combined Heat and Power Facility. The project consisted of a new chilled water plant, cogeneration plant and emergency power back-up system.

This project has provided unique and complex experiences as described below:

  • New buildings planned for nanotechnology research and new residential life dormitories were to be constructed just North and South of the CHP Facility: Site assessments were necessary concerning air quality provisions, vibration mitigation, noise mitigation and electromagnetic interference mitigation.

  • As CHP resides in a prominent location on campus, a unique exterior concrete panel design was created to fit campus architectural scheme.

  • Land, being a premium for ASU, required a compact and efficient design for the 76,000 square foot facility fit on a compact footprint.

  • As the new CHP Facility is to provide 12.47 KV power, chilled water and steam to seven new research buildings, the plant is required to operate in an island mode if the utility were to suffer a catastrophic outage.

  • Simultaneous construction of three new research buildings required APS Energy Services to coordinate all engineering, subcontractors and construction efforts around and interconnected with the new CHP.

    • APS Energy Services is, through its NorthwindTM Phoenix operations, providing electrical and thermal utilities to ASU research facilities until 2024. As the loads are being phased, the plant is being brought on line in phases. This requires studies and projections of current and future loads to build out the plant just ahead of the new loads being put onto the ASU system. This plant, at full build out, will allow ASU the capacity to supply normal power, emergency power, steam and chilled water for the following loads:

  • Chilled Water: 24,000 Tons
  • Steam: 160,000 lbs/hr
  • Power: 18 MW

  • Cogeneration Power: 18 MW (14 MW from the Combustion Turbine Generator and 4 MW from the Steam Turbine Generator)

  • Emergency Power: 6,000 kW

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    City of Flagstaff Cogeneration Plant

    APS Energy Services completed the design and construction of a cogeneration unit at the Wildcat Hill Wastewater Treatment Plant. The project provides Wildcat Hill Wastewater Treatment Plant with a biogas reciprocating engine capable of producing approximately 292 kilowatts (kW) of electric power and 27,000 mmbtu heat at a 7,000 foot elevation at full load.