Allied - On-Site Cogeneration Systems
Cogeneration is a variation of distributed generation, but it is an often misused and misunderstood term. A common thought is that cogeneration means running a generator in parallel with the utility grid, or 'co-generating'. While this is often done, this is not the meaning of the term. Cogeneration is simply using one energy source to produce two separate forms of energy. Cogeneration is also known as combined heat and power (CHOP). In a correctly designed application, one of these forms of energy may be considered 'free', since it is a by-product of the production of the primary energy form. Cogeneration is a method by which an energy user can control and reduce energy costs by utilizing the heat that would normally be wasted and use some or all of it for the thermal requirements of a facility.
Cogeneration is accomplished by utilizing the exhaust gas heat from the internal combustion engine driving the generator (which would normally be lost 'up the stack'), the engine cooling jacket water, oil cooling waste heat or a combination of these. This waste heat can be utilized in a direct application for desiccation, drying or heating various materials or for space heating applications, or may be passed through heat exchangers to produce heated air, hot water or steam. This 'free energy' can either be used in its initial form or may be converted to useable energy for boiler systems, chillers, air conditioning and many other applications, and will contribute significant additional savings to a facility using on-site generation.