Stand-alone and grid-connected performance analysis of a regenerative micro gas turbine cogeneration plant

Distributed generation is an attractive way of producing energy, minimizing transport losses and enhancing energy efficiency. Micro gas turbines in distributed generation systems add other advantages such as low emissions and fuel flexibility. The objective of this paper is to summarize the experimental data from a small-capacity cogeneration plant that consists of a natural gas fired 28 kWe microturbine and a hot-water waste-heat boiler installed at CREVER's testing facilities in Tarragona. The results include the electrical efficiency, natural gas consumption, electrical power quality, thermal power production and air emissions at different loads and ambient temperatures. The electrical efficiency is in the range of the specifications provided by the manufacturer and decreases considerably when the power output drops. Thermal production at full load is around 57 kW. Air emissions are very low at full load and do not increase appreciably until the load is below 60-70 per cent of the full load capacity. The results confirm that the power quality and air emissions in microturbines comply with the existing legal limits, and that they are very competitive in comparison with other technologies in these aspects. Thus, considerable market development is expected in the coming years, although further research. and development will be needed.