Combined Heat & Power (CHP)

Natural gas is a key fuel input for energy systems that represent new technologies with opportunities for reduced air emissions, higher system efficiency, and greater reliability.

Combined heat and power (CHP), also known as cogeneration, is the simultaneous production of electricity and heat from a single fuel source such as natural gas. CHP represents about 12% of total current U.S. generating capacity (approximately 83 GW). NRRI noted in a June 2014 paper: "About 87 percent of the current installed CHP capacity resides in the industrial sector, with the remaining capacity in the commercial or governmental sectors. The three sectors with the most CHP capacity are chemicals, refining and paper."

Natural gas fuels 70% of existing CHP capacity in the U.S. and is likely to be the key fuel input for CHP going forward. As NRRI observes: "The abundance of natural gas will make gas-fired CHP systems the preferred technology of the future. The scale of CHP systems ranges from the micro, residential scale of around 1 kW to large-scale industrial systems with a capacity greater than 100 MW."

The U.S. EPA notes that "gas turbines produce a high quality (high temperature) thermal output suitable for most combined heat and power applications...There is a significant amount of gas turbine based CHP capacity operating in the United States located at industrial and institutional facilities. Much of this capacity is concentrated in large combined-cycle CHP systems that maximize power production for sale to the grid. However, a significant number of simple-cycle gas turbine based CHP systems are in operation at a variety of applications including oil recovery, chemicals, paper production, food processing, and universities."

CHP is environmentally beneficial. EPA reports that, "because of their relatively high efficiency and reliance on natural gas as the primary fuel, gas turbines emit substantially less carbon dioxide (CO2) per kilowatt-hour (kWh) generated than any other fossil technology in general commercial use."

Fuel Cells use "hydrogen as the fuel in an electrochemical process, similar to what occurs in a battery, that generates electricity" (EPA). The primary fuel source for the fuel cell is hydrogen, which can be obtained from natural gas and other fuels containing hydrocarbons. Fuel cells provide great advancements in efficiency and lower emissions. The National Academies of Science noted in an Oct. 2009 report that, looking ahead, "natural gas-powered fuel cells could become mainstream and generate significant amounts of electricity."

Northeast states have programs underway to advance CHP as an option for commercial and industrial applications.

CHP Systems Include:
  • Reciprocating Engines
  • Combustion or Gas Turbines
  • Steam Turbines
  • Microturbines
  • Fuel Cells


For Further Information:

AGA's 2013 analysis of the CHP Opportunity in the U.S.

U.S. EPA's CHP Partnership

NYSERDA

MA Dept. of Energy Resources