In fall 2012, NC State began powering its main campus using cogeneration, or combined heat and power (CHP) as it’s also known. The recently-completed renovation of Cates Utility Plant on campus increases the 11 megawatt facility’s efficiency by roughly 35 percent. It is also expected to reduce the university’s greenhouse gas emissions by 8 percent, building on a 7 percent reduction from 2008 to 2010 and moving NC State closer toward its goal of climate neutrality by 2050.
Following eight years of planning, the renovation began in January 2011 as a $61 million performance contract with Ameresco, Inc., which guaranteed $4.3 million of energy savings in the first year. Utilizing the state’s largest performance contract at the time of construction, the facility will pay for itself in energy savings over 17 years – without using any additional state funding.
Whereas traditional power plants lose 60% of their energy from the burning of fuel, the Cates Plant converts this waste heat to steam, which is used to heat nearby buildings through a district energy system. With two gas-fired 5.5 megawatt combustion turbines and 50,000 PPH (pound per hour) heat recovery steam generators, the plant efficiently services approximately 8 million gross square feet of campus building space. An interactive online graphic shows how the new facility operates.
In addition to energy savings and helping NC State become more sustainable, the facility is also a resource for teaching students about energy efficient technologies.