CHP Makes Sense for Universities

Reducing energy costs, cutting carbon emissions.


View of the 25 MWe General Electric gas turbine installed at the University of Minnesota CHP facility. Photo courtesy University of Minnesota.Combined heat and power (CHP) uses byproduct heat from electric generation as the energy source for other applications such as steam for space heating, domestic hot water and/or absorption cooling. CHP, sometimes also called co-generation, represents an opportunity to dramatically increase total system efficiency. These applications often use natural gas as the primary energy source. When systems replace coal-fired electric power plants or coal-fired heating plants, they also reduce total emissions and virtually eliminate sulfur oxide and particulate emissions.

Makes sense for universities

Many universities supply energy to dozens or even hundreds of buildings from central power and heating plants. This is an exceptional opportunity for CHP. The central heating plant usually supplies medium- and high-pressure steam for space heating, laundry and sometimes food service and laboratory operations. In some cases, the university is also affiliated with healthcare facilities, which have additional requirements for steam and hot water. The university often also supplies chilled water for chillers and other purposes.

In most cases, the demand for electric power, heat and chilled water is year-round, 24 hours a day. Thus, the heat captured from power generation can be fully utilized. A supplementary steam system may sometimes used for peak winter heating periods.

Cutaway view of a typical gas turbine. For heat recovery purposes, a heat recovery steam generator is connected to the turbine exhaust, which is at a temperature of 700°F or higher. Illustration courtesy Solar Turbines.DOE report indicates potential

According to a March, 2016 report by the U.S. DOE titled “Combined Heat and Power (CHP)Technical Potential in the United States,” there currently are 272 applications of CHP by colleges and universities in the U.S. These facilities have a total capacity of 2,674 MWe. Thus, the average university system is about 10 MWe. Most of these systems are natural gas-fired steam turbines, gas turbines and engines. The report notes that for many educational institutions, the demand for electric power and for steam is often coincident, thus making these systems especially attractive.  

The report indicates that the national potential for these systems is 13,932 MWe. Thus, to date we have achieved 20% of the potential in this area. In many cases, adoption of CHP is being considered in conjunction with decommissioning or mothballing coal-fired generation and heat plant units.

University of Arkansas

A recent example of an institution that has taken this route is the University of Arkansas at Fayetteville. Scott Turley, Executive Director of Campus Utility Services, explains that a decision was made in 2013 to install a 5.2 MWe gas turbine generating unit to supply campus electric energy. This unit was sized to the school’s base steam demand, and uses a heat recovery steam generator (HRSG).

Turley explains, “The CHP system can satisfy the full campus requirement for steam for five months of the year. Under winter-load conditions, the HRSG system can furnish approximately 35% of the campus steam requirement.” This installation was an important element in the university’s Climate Action Plan, which is based on reducing source air emissions. Because the central station electric power it replaces is 75% coal-fired, the contribution was significant.

Solar turbines taurus unit

The gas turbine and HRSG are located in the existing 1956 heating plant building. The building currently also houses ten Miura high pressure steam boilers. The CHP system went into operation in February of 2016. The turbine used is manufactured by Solar Turbines. According to Chris Lyons from Solar Turbines, the unit is a Taurus 60-7301 with an ISO-rated output of 5.2 MWe.

Lyons indicates that these turbines have very long major maintenance intervals. “Approximately every 30,000 hours the engine is overhauled to bring it back to new conditions. In addition, Solar Turbines does semi-annual inspections to assure the units do not have any issues.”

Photo illustrates the inlet side of the heat recovery gas generator at the University of Arkansas. Photo courtesy Cleaver Brooks.

According to Lyons, this unit used alone has an efficiency of 30%, but when used with an appropriately sized HRSG, the system efficiency jumps to 77.8%, and when used with supplemental firing of the exhaust heat, can increase to 88.8%. The HRSG is manufactured by Cleaver-Brooks, and can produce up to 29,500 pph of 250 psig saturated steam.

Fuel efficiency soars

Because of this high system efficiency, it is estimated that the project will divert 35,000 metric tons of carbon dioxide equivalent emissions from the atmosphere. The University cites this as a major step to its goal of complete carbon neutrality, while also saving money for the school. According to Turley, based on the first six months of operation, the CHP system is projected to reduce utility bills for the University by $420,000.

A recent speaker at a Technology & Market Assessment Forum, sponsored by the Energy Solutions Center, was Dalia El Tawy from Siemens Energy. She presented information on a variety of CHP applications, several of which were university campus projects. One was the University of New Hampshire, where a recent installation includes a 7.8 MWe Siemens gas turbine, which can operate on natural gas or landfill biogas collected at a nearby site.

Cuts emissions from power plants and landfills

Through use of a HRSG, the facility also supplies up to 12 MW of heat for campus heating and cooling. Again, this facility contributes to carbon emission goals not only by reducing campus and utility emissions, but also by reducing landfill gas atmospheric emissions. According to Tawy, the facility has achieved 99.02% average availability.

Engine generation CHP

Smaller campuses can also benefit from CHP. Another example cited by Tawy is Wesleyan University in Middletown, Connecticut, where a 676 kWe Guascor engine-generator at an athletic facility also feeds into the campus microgrid, and the byproduct heat is used for heating and domestic hot water applications. It is estimated that this project provides savings of $1,000 per day.

Another large-scale example is the recent completion by the University of Minnesota of a CHP facility on the Mississippi River in St. Paul. The facility serves the sprawling university campus and uses a 25 MWe GE gas turbine with a waste heat boiler, plus supplementary duct heaters to also supply steam for campus heat and domestic hot water.

According to University Director of Energy Jerome Malmquist, the guiding principles of the University’s utility operations are reliability, sustainability and cost management. He adds, “The campus has a goal to reduce carbon emissions 50% by the year 2020, and to zero by 2050. Modeling predicts that this project will reduce the carbon footprint by 60,000 tons or 10% to 13%. The same models show annual operations savings of $2 million. With regard to reliability, this system has the capacity to power all critical loads on this research and medical campus.”

Major portion of campus steam needs

University Vice President for Facilities Management Mike Berthelsen notes that the plant will supply approximately 85% of the campus steam needs, and will annually generate 166 million kilowatt-hours of energy. A specific need for the high-pressure steam is for sterilization and other research purposes at large campus medical and laboratory facilities.

The University recently completed an electric energy interconnection agreement with electric power supplier Xcel Energy. The natural gas supplier to the University, CenterPoint Energy, recently gave its “Most Innovative Project of the Year” award to the University for the project.  

CenterPoint energy worked with university

Paul Albinson, key account manager for CenterPoint, worked closely with the university on this project. He notes, “To ensure financial sustainability and reliability, the University worked with CenterPoint Energy to put into service a new service line to the CHP plant to provide natural gas, and also negotiated long term delivery contracts for this to be a successful project for all. We expect to provide large rebate for the conservations efforts within the facility, mainly the energy recovery from the heat recovery steam generator.”

Hitting both energy and environmental targets

With states and governing bodies looking for ways to cut operating costs at educational institutions, CHP is a major opportunity. With these projects, the sponsoring institutions may be motivated not only by energy and dollar savings, but also by the potential of CHP projects to contribute to lowering atmospheric carbon emissions and other air pollutants. It is an investment that can pay dollar and environmental dividends for decades.



DOE CHP Database  

General Electric Power Generation

Guascor Engines

Solar Turbines

This article originally appeared in the Gas Technology Spring 2017 issue .

Top Plant
The Top Plant program honors outstanding manufacturing facilities in North America.
Product of the Year
The Product of the Year program recognizes products newly released in the manufacturing industries.
System Integrator of the Year
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
October 2018
Tools vs. sensors, functional safety, compressor rental, an operational network of maintenance and safety
September 2018
2018 Engineering Leaders under 40, Women in Engineering, Six ways to reduce waste in manufacturing, and Four robot implementation challenges.
GAMS preview, 2018 Mid-Year Report, EAM and Safety
October 2018
2018 Product of the Year; Subsurface data methodologies; Digital twins; Well lifecycle data
August 2018
SCADA standardization, capital expenditures, data-driven drilling and execution
June 2018
Machine learning, produced water benefits, programming cavity pumps
Spring 2018
Burners for heat-treating furnaces, CHP, dryers, gas humidification, and more
October 2018
Complex upgrades for system integrators; Process control safety and compliance
September 2018
Effective process analytics; Four reasons why LTE networks are not IIoT ready

Annual Salary Survey

After two years of economic concerns, manufacturing leaders once again have homed in on the single biggest issue facing their operations:

It's the workers—or more specifically, the lack of workers.

The 2017 Plant Engineering Salary Survey looks at not just what plant managers make, but what they think. As they look across their plants today, plant managers say they don’t have the operational depth to take on the new technologies and new challenges of global manufacturing.

Read more: 2017 Salary Survey

The Maintenance and Reliability Coach's blog
Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
One Voice for Manufacturing
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Maintenance and Reliability Professionals Blog
The Society for Maintenance and Reliability Professionals an organization devoted...
Machine Safety
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
Research Analyst Blog
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Marshall on Maintenance
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
Lachance on CMMS
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
Material Handling
This digital report explains how everything from conveyors and robots to automatic picking systems and digital orders have evolved to keep pace with the speed of change in the supply chain.
Electrical Safety Update
This digital report explains how plant engineers need to take greater care when it comes to electrical safety incidents on the plant floor.
IIoT: Machines, Equipment, & Asset Management
Articles in this digital report highlight technologies that enable Industrial Internet of Things, IIoT-related products and strategies.
Randy Steele
Maintenance Manager; California Oils Corp.
Matthew J. Woo, PE, RCDD, LEED AP BD+C
Associate, Electrical Engineering; Wood Harbinger
Randy Oliver
Control Systems Engineer; Robert Bosch Corp.
Data Centers: Impacts of Climate and Cooling Technology
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
Safety First: Arc Flash 101
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
Critical Power: Hospital Electrical Systems
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
Design of Safe and Reliable Hydraulic Systems for Subsea Applications
This eGuide explains how the operation of hydraulic systems for subsea applications requires the user to consider additional aspects because of the unique conditions that apply to the setting
click me