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, biomass, biogas, coal, waste
heat, or oil.
CHP is not a single technology, but an
integrated energy system that can be modified depending upon the needs of the
energy end user.
• Onsite generation
of electrical and/or mechanical
• Waste-heat recovery
for heating, cooling,
dehumidification, or process applications.
• Seamless system
for a variety of technologies, thermal applications, and fuel
types into existing building infrastructure.
CHP vs. Separate Heat and
Power Production: CHP is the
simultaneous production and use of electricity and thermal energy from a single
fuel. CHP is inherently more efficient than the separate generation of
electricity from central station power plants and thermal energy from boilers
or other heating equipment. (Click on the image for an enlarged view.)
The two most common CHP system
• Gas turbine
or engine with heat recovery
• Steam boiler with steam turbine
Gas turbine or reciprocating engine CHP
systems generate electricity by burning fuel (natural gas or biogas) to
generate electricity and then use a heat recovery unit to capture heat from the
combustion system’s exhaust stream. This heat is converted into useful thermal
energy, usually in the form of steam or hot water. Gas turbines/engines are
ideally suited for large industrial or commercial CHP applications requiring
ample amounts of electricity and heat.
Steam turbines normally generate
electricity as a byproduct of heat (steam) generation, unlike gas turbine and
reciprocating engine CHP systems, where heat is a byproduct of power
generation. Steam turbine-based CHP systems are typically used in industrial
processes, where solid fuels (biomass or coal) or waste products are readily
available to fuel the boiler unit.
CHP technology exists in a wide variety
of energy-intensive facility types and sizes nationwide, including:
• Industrial manufacturers - chemical, refining, ethanol, pulp
and paper, food processing, glass manufacturing.
• Institutions - colleges and universities, hospitals,
prisons, military bases.
• Commercial buildings - hotels and casinos, airports,
high-tech campuses, large office buildings, nursing homes.
• Municipal - district energy systems, wastewater treatment
facilities, K-12 schools.
• Residential - multifamily housing, planned communities.
BENEFITS OF CHP
CHP can play an important role in
meeting the United States’ energy needs as well as in reducing the
environmental impact of power generation, including:
CHP requires less fuel
to produce a given energy output, and avoids transmission and distribution
losses that occur when electricity travels over power lines.
CHP can be designed to
provide high-quality electricity and thermal energy to a site regardless of
what might occur on the power grid, decreasing the impact of outages and
improving power quality for sensitive equipment.
Because less fuel is
burned to produce each unit of energy output, CHP reduces air pollution and
greenhouse gas emissions.
CHP can save
facilities considerable money on their energy bills due to its high efficiency
and can provide a hedge against unstable energy costs.
Reprinted from the U.S. Department of Energy’s
Industrial Technologies Program (ITP) Website. For more information on
distributed energy technologies and combined heat and power (CHP) systems,