Duke Energy Combined Heat and Power System Currently Under Construction
Clemson University to increase energy reliability with islanding capability, self-healing smart grid
A new Combined Heat and Power (CHP) plant owned and operated by Duke Energy will generate 15 megawatts (MW) of electricity as early as November 2019. The system will provide South Carolina’s Clemson University with steam, and allow the university to island from the grid to keep critical loads operational. This application is essential to meeting the university’s long-term power needs, and allows Clemson to lower its greenhouse gas emissions, according to NewsStand. By coupling the steam and electricity produced, Duke Energy anticipates the reduction in CO2 equivalent to surpass 60,000 metric tons.
Combined heat and power, or cogeneration, is the production of electricity and the utilization of heat for the production of steam. CHP applications provide efficient and resilient power to facilities that need to remain operational, such as universities, military installations and many manufacturers.
From 2008-2013, the university experienced 35 outages with restoration of power taking up to four days.
“Keeping the university as [energy] reliable as possible is key, and while 15 MW is short of our 26 MW peak load, we will be able to keep the most critical items going despite a grid outage,” said Bret McCarley, Clemson University Associate Director, Electrical.
Clemson is investing heavily in campus electrical resilience through the development of a self-healing smart grid for their medium voltage distribution system, according to Darrell Wildner, Project Manager for Jacobs Engineering, the firm that helped design the electrical specifications. This system will include protection relaying when islanding from the grid, which will reduce or eliminate restoration time in the event of a loss of power.
Clemson University, which sits on 1,400 acres, is home to 24,951 students and 5,392 faculty and staff. The new CHP will capture waste heat from the production of electricity to produce thermal energy, which Duke will sell to Clemson to be used to heat buildings and water on campus, according to NewsStand.
This is the first project in Duke Energy’s CHP program to receive regulatory approval. The $50.8 million design includes a 15 MW combustion turbine and a supplementary-fired heat recovery steam generator (HRSG), also capable of being fresh-air fired, according to Burns & Mcdonnell, the construction engineering company providing engineering services for the project. The system can also operate in simple cycle using the Heat-Recovery Steam Generator(HRSG) bypass stack. In the event of a grid outage, the plant will have black-start capabilities and will operate in island mode to supply electricity and steam to the campus.
In this utility ownership model, Duke Energy owns the facility on its side of the meter, as part of its rate-based generation portfolio for the benefit of all South Carolina customers, according to Zachary Kuznar, Director of Business Development for Duke Energy, in an article in District Energy Magazine. The asset has the ability to produce up to 100,000 pounds per hour of steam. Revenues from this transaction flow back to all South Carolina customers.
These types of projects have tremendous value to the host site, the utility and all customers in South Carolina, according to an article in District Energy Magazine, co-written by Kuznar and Kurt Koenig, previous National Business Manager for Distributed Generation, Burns & McDonnell. With this type of partnership, Duke Energy and the rest of its customers in South Carolina receive an efficient, low-cost, baseload grid generation asset, while reducing air emissions.
There are currently about 274 CHP systems installed in universities and colleges across the United States, with an overall generation capacity of 2,535 MW. According to ICF, there remains a technical potential capacity of 13,932MW specific to colleges and universities, nationally.
The U.S. Department of Energy Southeast Combined Heat and Power (CHP) Technical Assistance Partnership (TAP) at North Carolina State University’s NC Clean Energy Technology Center, promotes and assists in transforming the market for CHP, waste heat to power, and district energy technologies/concepts in the following eight southeast states: North Carolina, South Carolina, Tennessee, Kentucky, Georgia, Alabama, Mississippi and Florida, as well as Puerto Rico and the U.S. Virgin Islands. The CHP TAP network provides fact-based, unbiased education and technical assistance to help energy end-users consider the benefits of combined heat and power.
Top Clemson University campus photo from www.clemson.edu