Power Plant

Additional Sources for CHP Industry Information

District Energy Buyers Guide
Prepared by the International District Energy Association

Improving Steam System Performance: A Sourcebook for Industry
The US DOE Office of Industrial Technology energy efficiency sourcebook

CHP On Campus Online Guidebook
Online resource describing the benefits of CHP for universities and how to develop on campus projects.

Presentations, Publications & Meeting Reports
A list of presentations, publications, reports and past workshops prepared by Mid-Atlantic CHP TAP is provided here

Glossary of Industry Terms

Absorption Chiller

Water chiller based on absorption of refrigerant vapor into a liquid solution, pumping of the solution to elevated pressure, and the release (desorption) of refrigerant vapor through addition of heat; absorption chillers require less energy because the pumping process involves a liquid; direct-fired chillers employ natural gas burners, indirect-fired chillers use steam or hot water from a separate process (such as the hot exhaust gases from electric generation); single-, double-, and triple-effect chillers employ multiple stages of desorption and internal use of waste heat to boost efficiency


Combined heat and power; CHP systems are also known as cogeneration, trigeneration, or total energy systems

Demand Charge

Charges for the use of electricity based on the maximum power requirement, electrical demand, during a specified period of time ($/kW)


A solid or liquid material with an affinity for absorbing water molecules

Distributed Generation

Distributed generation; CHP is a type of DG system in which thermal energy that otherwise would be wasted is recovered and reused

Distributed Resources

This is a generic term that refers to "small" generators or demond response programs that are distributed throughout a region. These small generators may be owned and operated by utilities or thier customers.

Distributed Response

This refers to actions taken on the part of customers to reduce power consumption during high load periods. These actions may be taken voluntarily in response to price signals (see Real Time Pricing below) or customers may join programs in which they are paid in return for granting their utility the right to call on them to reduce demand when needed.


Electrical generator using a reciprocating, Sterling, or rotary engine

Enthalpy Wheel

Heat exchanger rotating through building supply and exhaust air flows to transfer energy from one air stream to the other

Evaporative Cooling

Lowering the temperature of air through the evaporation from a water or wetted membrane; direct evaporative cooling adds water to the supply air while indirect evaporative cooling adds water to the exhaust air and incorporates a heat pipe or thermal wheel for indirect cooling of the supply air

Fuel Cell

Device for producing electricity using a chemical process rather than conventional combustion processes with electric generators

Heat Wheel

Heat exchanger rotating through building supply and exhaust air flows to transfer heat from one air stream to another


Indoor air quality



Latent Cooling Load

Amount of cooling required to reduce humidity of air in conditioned space to specified level for comfort

Line Losses

Electric energy lost as heat in power transmission lines

Microturbine Power Generator

Turbine-engine driven electrical generator with output power generally under 100 kw

Power Availability

Percent or fraction of the time (hours) power is available in a year (8760 hours)

Real Time Pricing

Charges for electrical demand and consumption based on instantaneous cost of production and distribution as opposed to non time sensitiverates or fixed time-of-day rates

Sensible Cooling Load

Amount of cooling required to reduce the temperature of air in the conditioned space to a specified level for comfort

Thermal Wheel

Heat exchanger rotating between two air flows to transfer heat from one to the other

Ton (or Refrigeration Ton)

Quantity of cooling available from melting 2000 pounds of ice; 12,000 Btu/h or 3.1413 kW

Vapor Compression Air Conditioning

Cooling system based on compression of a gaseous refrigerant to a high pressure, and heat transfer with changes of state (i.e. Liquid and vapor) to produce useful heating or cooling

Waste Heat

Portion of the energy input to a mechanical process which is rejected to the environment

Good List of Terms used in Electric Utility Industry