CHP System | Advantages | Disadvantages | Available sizes |
Gas Turbine | · High reliability · Low emissions · High grade heat available · No cooling required | · Require high pressure gas or inhouse gas compressor · Poor efficiency at low loading · Output falls as ambient temperature rises |
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Micro Turbine | · Small number of moving parts · Compact size and light weight · Low emissions · No cooling required | · High cost · Relatively low mechanical efficiency · Limited to lower temperature cogeneration applications | 30 KW - 250 KW |
Internal Combustion Engine | · High power efficiency with part-load operational flexibility · Fast start up · Relatively low investment cost · Can be used in island mode and have good load following capability · Can be overhauled on site · Operate on low pressure gas | · High maintenance costs · Limited to lower temperature cogeneration applications · Relatively high air emissions · Must be cooled even if recovered heat is not used · High level of low frequency noise | <5 MW in distributed generation High speed (1200 rpm) ≤ 4 MW Low speed (102 - 517 rpm) 4 - 75 MW |
Steam turbine | · High overall efficiency · Any type of fuel can be used · Ability to meet more than one site heat grade requirement · Long working life and high reliability · Power to heat ratio can be varied | · Slow start up · Low power to heat ratio | 50 KW - 250 MW |
Fuel cells | · Low emission and low noise · High efficiency over load range · Modular design | · High cost · Low durability and power density · Fuels requiring process | 5 KW - 2 MW |