The production of electricity from conventional energy sources has exacerbated problems, such as global climate change, pollution, the degradation of the quality of life and, in general, social problems stemming from the management of mineral resources. Specifically in Greece, an outmoded and polluting central energy system is still used. Electricity supply problems are constantly intensifying, because of the continuous increase in demand, with large seasonal imbalance and peaks during the summer tourist season.
Recent EU directives promote the evolution of the existing power generation model into a distributed generation model, with renewable energy sources playing a dominant role. For the specific climatic conditions of Greece, the use of solar energy for combined heat and power production may prove to be an economically viable solution.
The combination of Stirling engines with solar radiation reflectors is now a common method of cogeneration and trigeneration. Some of the solar systems already installed and operating are 50 kW in Saudi Arabia, 9 kW in Germany and 10 kW in Spain.
To this end and for research purposes, NTUA’s Laboratory of Applied Thermodynamics, Cooling Technology & Refrigerated Vehicles has already installed a Stirling engine. The specific cogeneration unit is powered by natural gas and its products are electricity and heat. In a commercial application, the electricity would be fed into the grid, while the heat would be used for district heating/cooling or industrial applications.
Characteristics
Fuel supply 1.2-3.8 m3/h
Electrical power 2-9.5 kW
Thermal power 8-26 kW
Electrical efficiency 22-24%
Overall performance rating 92-90%
ΝΟ pollutants 80-120 mg/m
CΟ pollutants 40-60 mg/m
