25 KW to 500 KW
Microturbines are small high-speed generator plants. Microturbines evolved from automotive and truck turbochargers, auxiliary power units for airplanes and small jet engines. They consist of a single shaft connecting a turbine, compressor and generator. Air is drawn in through a compressor into a recuperation unit that has been heated by the exhaust gases. The air flows into a combustion chamber where it is mixed with the fuel and burned. The hot gas is expanded through the turbine creating mechanical energy. The exhaust gases pass out through the recuperation unit to capture some of the remaining heat.
Performance and Efficiency
- Overall cogeneration efficiencies can reach 85%
- High heat-to-power ratio, so electrical efficiencies are only 20% to 30%.
- Predominately fuelled by natural gas.
- Diesel, petrol or biogas can also be used.
Commerical, Residential, Small Industry
- The heat produced by a microturbine can be used to produce low-pressure steam or hot water for on-site requirements.
- Microturbines are well suited to provide heat and electricity to small commercial applications such as restaurants, hotels and offices.
| Hospitals, such as this one pictured here in Italy, are ideal applications of microturbines for use in combined heat and power mode.|
|Microturbines can be applied in remote oil extraction applications such as this off-shore oil rig off the coast of Mexico.|
Advantages and Disadvantages
|Cost Range for Microturbines|
|Installed Capital Cost ($/kW)||1,300 – 2,500 |
|Operating and Maintenance ($c/kWh)||0.5 – 1.6|
|Levelized Cost ($c/kWh)|
|8000hrs/year||5.0 – 7.0|
|4000hrs/year||7.0 – 11.0|
|Source: WADE, 2006|
Mircoturbines costs remain relatively high, but manufacturers aim for significant mass production of standardized units relative to all other DE generation technologies, which could lower the cost and enhance competitiveness of these devices in cogeneration applications.