Combined heat and power systems (CHP) simultaneously produce electrical power and thermal energy, lowering the cost of heat and electricity while reducing harmful emissions. Many of these systems — which also provide a more reliable source of energy — rely on natural gas engines.
Universities across the country are taking advantage of CHP systems. There are 281 CHP systems installed on U.S. university campuses, according to the U.S. Department of Energy, accounting for more than 2,600 MW of power. Reciprocating engines and combustion turbines are the leading prime movers.
CHP systems make the grade
The following examples show why universities are embracing CHP.
Massachusetts Institute of Technology is expanded its existing CHP gas turbine plant, doubling its capacity with two 22-MW turbines. The upgraded plant uses natural gas for all normal operations, lowering emissions by more than 25% from 2014 levels. The existing plant has been in operation since 1995.
At the University of Notre Dame, a CHP plant supplies half of campus power needs, as well as steam for heating, hot water and air conditioning. Natural gas helped reduce emissions by 40%. The university has plans to install combined-cycle combustion gas turbines to produce both electricity and steam at higher efficiency and with lower emissions.
A a 22.8-MW combustion turbine-driven CHP system was installed at the University of Minnesota to meet the need for additional thermal energy. The system has an efficiency of about 80% and helped cut the institution's utility footprint by 30%.
A 1,500-kW lean-burn natural gas engine and chiller plant at the University of Redlands in California produces a majority of the campus' energy, as well as heating and cooling for a third of the buildings on campus. Redlands reduced its carbon footprint by 30%.
CHP stars in resiliency
Higher education continues the move toward resiliency — the ability of a power system to withstand disruptive events. CHP fits the bill because the technology can continue to operate during a major power outage from extreme weather or other causes. This capability is critical for universities with medical facilities or those conducting important research. The following ENERGY STAR CHP Award winners are good examples.
The CHP system at the University of Maryland's Upper Chesapeake Medical Center incorporates a 2-MW gas-fired internal combustion engine and a 350-ton absorption chiller. Heat recovered from the engine provides space heating and hot water, and powers the absorption chiller for air conditioning. In addition to providing resilience, the system saves an estimated $300,000 a year in operating costs.
The University of Massachusetts Medical School received the award for its third CHP expansion: the addition of a 7.5 MW natural gas-fired combustion turbine generator. With an efficiency of 73%, the system requires 20% less fuel than conventional separate electricity and steam production. The expanded power plant generates up to 90% of campus electricity needs and reduces energy services costs by approximately $3 million annually.
Take advantage of natural gas
By relying on natural gas-fueled CHP systems, universities are lowering operating costs, improving resiliency and reducing their environmental impact.
