ENERGETIC PERFORMANCE ASSESSMENT OF A THERMO-SOLAR GREENHOUSE FISH (NILE TILAPIA) HATCHERY

Energetic performance of a thermo-solar greenhouse representing a fish hatchery system was suggested, developed and investigated. The developed system was mainly consisted of a double cover greenhouse coupled with solar collector and heat exchanger for water heating. The main aim was to control the water environment, namely temperature and dissolved oxygen, of a fish (Nile Tilapia) hatchery at the desired levels. The main experimental work was carried out during the period from December 2014 to February 2015. The suggested and investigated system based mainly on solar energy as the source of power. However, an auxiliary heating system, namely an electric heater was used upon request. The experimental system was constructed and investigated at the research farm, Faculty of Agriculture, Kafrelsheikh University (31.07°N and 30.57°E) Kafrelsheikh governorate, Egypt. Environmental parameters; namely temperature, solar radiation, relative humidity, wind speed and water quality in terms of dissolved oxygen were monitored. The results indicated an efficient control in water temperature and quality. The average temperature and dissolved oxygen concentration of fish pond water throughout the whole experimental period were 26.8 (SD = 0.15) °C and 7.62 (SD =0.68) ppm respectively. The average value of air temperature rise inside the greenhouse was 8.4 °C. The average value of total daily water energy gained via the heat exchanger system was 18.185 MJ/ day per m^2of the fish pond water surface area at an average value of 13.433 MJ/ (m^2.day) of the incident solar radiation on the horizontal plane. As a conclusion the weekly average percentage of energy contribution of both greenhouse action and heat exchanger operating times were 58.13 and 41.87% respectively as a percentage of the whole operating time.