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District Energy System Glossary

The following items are commonly used acronyms and terms within the Metro Nashville District Energy System (MNDES).

  • ARFA: Amended and Restated Fuel Agreement, which is the fuel purchase contract for the MNDES
  • ARMA: Amended and Restated Management Agreement, which is the contract for the design and construction of an Energy Generation Facility, improvement of an Energy Distribution System and long term operation and management of the MNDES
  • CNE: Constellation NewEnergy, LLC, which is the entity that operates the Metro Nashville District Energy system
  • DES: District Energy System, which produces heating and cooling mediums in the form of steam, hot water and chilled water in a central generating facility plant and distributes them to multiple users
  • DHC: District Heating and Cooling
  • EDS: Energy Distribution System, which is the network of supply and return pipes used to circulate the steam, condensate and chilled water to customers and includes the metering systems used to monitor their usage of the system
  • EGF: Energy Generation Facility, which is the central plant where steam for heat and chilled water for air conditioning are produced and distributed
  • FOC: Fixed Operating Component, which are fees received under the amended and restated management agreement (ARMA) by the system operator (SO) for operating and maintaining the district energy system (DES)
  • HVAC: An acronym that stands for heating, ventilating, and air conditioning
  • IDEA: International District Energy Association, which represents members who are district heating and cooling executives, managers, engineers, consultants and equipment suppliers
  • ISC: Initial System Customer, which refers to those customer buildings originally served by Nashville Thermal Transfer Corporation (NTTC) who remained on the MNDES at the commissioning of the new energy generation facility (EGF)
  • Metro: Metropolitan Government of Nashville and Davidson County, the local governing body
  • Metro Liaison (ML): The Metro Finance Director has appointed an individual to act on behalf of Metro and be the interface between the Project Administrator and Metro; currently filled by Bob Lackey
  • MNDES: Metropolitan Nashville District Energy System: the Metro-owned system that provides steam and chilled water from a central plant to multiple buildings in downtown Nashville.
  • NTTC: Nashville Thermal Transfer Corporation: a not-for-profit organization established in 1970 to build, own, and operate the original Nashville district energy system. This entity expired following the commissioning of the new EGF.
  • PA: Project Administrator
    • Operations of the MNDES fall under the purview of the Metro Finance Director
    • Metro Finance Director, in accordance with ARMA appoints a Contract Administrator, also known as the Project Administrator (PA)
    • PA is the point of management contact for the entire project; role is currently filled by Harry J. Ragsdale of Thermal Engineering Group, Inc.
  • SO: System Operator, a contractor as defined in the ARMA responsible for the operation and maintenance of the EGF and the EDS under a long-term operating agreement; role currently filled by CNE