1. CCHP Description
Electrical energy is usually supplied to facilities from municipal distribution systems.
The use of an electrical generator, equipped with high-efficiency heat recovery equipment offers the facility owner/operator the advantage of being able to supply base load power, at or below prevailing cost with substantial additional savings being obtained from the ability of the heat recovery equipment to supply waste thermal energy to other house loads.
Referred to variously as co-generation, tri-generation, or combined heat and power units, the basic concept is to combine a base load electrical generator with heat recovery equipment. Generators can be supplied as induction or synchronous machines, and typically use micro-turbines, or reciprocating engines as the prime movers. The most common fuel source is natural gas, though other fuels sources such as diesel or propane can also be employed.
The heat recovery equipment can provide hot air or hot water that can be tied directly to facility systems. An increasingly common application is the use of direct-fired chilling equipment that utilize waste heat to drive air conditioning or process chilling equipment.
2. CCHP Benefits
The most significant benefits of CCHP are a) the chance to generate electricity at a lower net kilowatt-hour cost, b) the ability to reduce electrical demand charges up to 100 percent of the rated capacity of the generator, and c) to offset the purchase of fuel in the form of oil, natural gas or propane, based upon the output of the generator’s recovered waste heat stream. Energy savings to the facility owner are generally calculated net of all capital and maintenance costs and represent true “bottom line” savings.
3. Process/How to Buy
The acquisition of a CCHP unit typically requires an engineering and economic evaluation of the facility in order to determine whether there is a suitable electrical and thermal load profile. This study allows the provider of the system to make a fair estimate of the savings and return on investment (ROI) of the project. A technical and economic analysis is a pre-requisite.