North Carolina State University - 11 MW CHP & District Energy System - Case Study
LOCATION: Raleigh, North Carolina
MARKET SECTOR: University
IN OPERATION SINCE: 2012
GENERATING CAPACITY: 11 Megawatts (MW)
THERMAL OUTPUT: 100,000 lbs/hour steam
FUEL: Natural Gas and Distillate Fuel Oil
EQUIPMENT: (2) 5.5 MW Gas Turbines
(2) 50,000 lb/hr recovery boilers
(2) auxiliary duct burners
750 kW Black start generator
TOTAL PERFORMANCE CONTRACT: $61 Million
ESTIMATED CHP SYSTEM COST: $26 Million
FIRST YEAR SAVINGS: $4.3 Million
20-YEAR SAVINGS: $103 Million
JOINT PROJECT BY: NCSU, Ameresco, Inc.
ENVIRONMENTAL BENEFITS: Reduces the University’s Greenhouse Gas Emissions by approximately 8%, or 33,000 metric tons CO2 equivalent. Alsreduces SO2 emissions.
North Carolina State University completed a CHP project in the fall of 2012 as part of a major Performance Contract with Ameresco, Inc. that delivered twnew CHP units, the replacement of three central plant boilers, a new 2000-ton chiller and other energy efficiency upgrades on the campus.
The CHP portion of the contract included the installation of tw5.5 MW combustion turbines and heat recovery steam generators at the Cates Utility Plant. The system supplies 30% of the North Campus’ peak power demand and reduces purchased electricity, yielding utility cost savings. By recovering exhaust heat from the turbines for the existing district energy system, the campus reduces overall energy costs while advancing its goal of carbon neutrality by the year 2050.
The DOE Southeast CHP TAP team at NC State provided technical assistance tthe NCSU Facilities team over the course of the planning and development process, including technical and cost reviews, as well as support on interconnection policies and requirements.
Reasons for Installing Combined Heat & Power
Incorporating a CHP system intNCSU’s current district energy infrastructure provides the University with many benefits, including:
- Achieve higher efficiency for concurrent electricity and steam generation; a 35% increase compared tseparate steam generation and electricity purchasing for a 73% overall CHP system efficiency
- Reduced operating costs for an incremental savings rate of approximately 6.6% for the campus
- Aiding in achieving LEED certification from U.S. Green Building Council for campus buildings
- Capability for operation during grid power outage
This project alshas immediate and lasting local economic benefits, creating an estimated 55 construction jobs for 1 ½ years, 34 U.S. manufacturing jobs for 1 year, 4 University operations positions, and 4 maintenance positions.