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Combined Heat and Power: A Clean, Local Energy Solution

From the Winter 2009 issue of Energy Matters

Photo of three tall metallic boxes sitting on a platform, with silver industrial pipes emerging vertically from the top of each. These are connecting to a horizontal metallic pipe and surrounded by a metallic structure.

Combined heat and power systems provide exceptional energy efficiency and emissions reduction for industries across the nation.
Source: UTC Power

DOE's Industrial Technologies Program (ITP) has identified combined heat and power (CHP) as one of the most important opportunities available today for increasing energy efficiency and reducing emissions. This article explains CHP technology uses and benefits, and ITP's effort to help the United States achieve a goal of 20% of CHP power generation by 2030.

The need for clean, efficient energy for the 21st century is moving a time-tested technology into the limelight. By providing on-site power generation, waste heat recovery, and system integration, combined heat and power (CHP) offers a realistic, near-term solution for exceptional energy efficiency and emission reduction.

As our nation faces growing electricity demand, volatile fuel costs, environmental concerns, and power reliability issues, DOE's Industrial Technologies Program (ITP) is working to boost CHP technologies to greater levels of efficiency and further expand the use of this clean energy solution. With proper technical and policy support, the goal of 20% generation capacity by 2030 can be achieved, saving approximately 5.8 quadrillion Btu per year, and avoiding 848 million metric tons of CO2 emissions. This is equivalent to removing more than 150 million cars off the road.

How CHP Works

Combined heat and power (CHP), or cogeneration, is the simultaneous production of electricity and heat from a single fuel source. A CHP system recovers the heat normally lost in electricity generation for use in cooling, heating, dehumidification, and other processes. Compared with separate generation of electricity and heat, CHP systems can operate at more than 80% efficiency.

CHP is not a single technology, but an integrated energy system that can be modified depending upon the needs of the energy end user. CHP can use a variety of fuels to provide reliable electricity, mechanical power, or thermal energy for industrial plants, universities, hospitals, or commercial buildings—wherever power is needed.

The diagram below compares the efficiency of a combined heat and power system with that of a conventional power plant. Learn more about how CHP works by visiting ITP's Combined Heat and Power Basics Web site.

This diagram is labeled "CHP Process Flow Diagram" and is divided into essential two sections. The left component is labeled "Traditional System," and underneath this text are two boxes(one above the other). The lower box is labeled "Power Plant" and the lower box is labeled "Boiler." Underneath these boxes is a label that reads "45% Efficiency." The right component is labeled "CHP System," with one box below this label that reads "CHP." Underneath this box is a label that reads "80% Efficiency." Between the right and left components, are arrows (one above the other) coming from each box that point toward each other. The top arrows are labeled "Electricity," and the bottom arrows are labeled "Heat."

Benefits for Peak Performance

Compared with separate heat and power production, combined heat and power systems provide many benefits, including:

  • Energy efficiency: CHP systems recycle waste energy and use it for heating and cooling; enhance fuel use efficiency; and increase the benefit to the customer from each cubic foot of natural gas or propane consumed.
  • Emissions reduction: Efficient CHP technologies decrease emissions of pollutants and greenhouse gases. What's more, CHP can use clean, renewable fuels such as biomass or biogas to provide electrical and thermal energy.
  • Energy reliability and quality: CHP can operate in parallel with the grid to enhance power reliability and support operations, or supply onsite generating capacity. CHP technologies deliver the high-quality power required by computer systems and sensitive manufacturing processes.
  • Energy security: CHP systems can operate independently of the grid to sustain critical services such as health care, communications, shelter, and public safety, after disasters.
  • Economic development: CHP systems directly relieve grid congestion, reduce or eliminate power purchases, and avoid the need to construct new power plants. In the case of alternate fuels, CHP systems enable the use of local energy resources and support high-tech manufacturing industries.
  • Job creation: Further development of and investment in CHP technologies will generate new jobs for highly skilled, technical workers, and boost local economies.

U.S. Combined Heat and Power in Operation

CHP Resources

Some of the following documents are available as Adobe Acrobat PDFs. Download Adobe Reader.

Currently, there are approximately 3,500 CHP sites in the United States, with a generating capacity of 85 GW or 9% of U.S. total capacity. This local, clean power generation is reducing annual fuel use by 1.9 quadrillion Btu and offsetting 248 million metric tons of CO2 emissions—equal to removing 45 million cars from the road.

Combined heat and power applications span industrial, commercial, and residential market sectors across all 50 states. Find information on CHP installations in your area by using the DOE-supported CHP Installation Database, the primary source for tracking CHP sites and market developments. The database provides details for each site on the facility, application, prime mover, capacity, and fuel type.

Breaking Down Barriers

Despite its proven benefits, a number of hurdles must be overcome to realize the full potential of CHP in the marketplace. Technical, regulatory, policy, and institutional barriers persist, despite successes at the state and regional level and recent federal legislation to boost tax credits for CHP. Read a summary (PDF 116 KB) of the latest CHP federal tax incentives. Download Adobe Reader.

ITP is committed to helping our nation overcome these barriers by working collaboratively with U.S. industry and other stakeholders to invest in significant technology improvements, and to transform the market at the federal, state, and regional levels. Ongoing efforts include:

These activities will help to expand the adoption of clean, efficient CHP technologies as a major source of electrical, mechanical, and thermal energy for the United States.

As ITP Program Manager Douglas Kaempf explains,"CHP represents a great near-term opportunity to save energy, reduce carbon emissions, and improve local economies. ITP is taking a lead role in enabling CHP to reach its potential."

For more information about ITP's CHP Program, contact Bob Gemmer.

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