INVESTIGATION AND UTILISATION OF A HYBRID HEATING SYSTEM OF BIOMASS BURNING ASSISTED SOLAR ENERGY FOR SWEET COLOURED PEPPERS GREENHOUSE

   In this study, a complete solar water heating system has been located beside two experimental greenhouses cultivated by sweet coloured peppers crop from 27^th of August 2010 until 26^th of July 2011.  The total heat energy required for heating the greenhouse was computed based on the requirements for heating a greenhouse reside in the task of adding heat at the rate at which it is lost. One greenhouse equipped with a complete solar heating system (two solar collectors, heat distributing system, and storage tank) connected to biomass burning unit as an auxiliary heater. Another greenhouse was connected to a complete solar heating system equipped with electric heater as an auxiliary heater to compare and investigate how much heat energy can be provided when using the renewable energy for greenhouse heating in winter and cold days. The thermal performance analysis of the solar heating system was experimentally determined, by measuring the temperature increase at various water inlet temperatures and intensity of solar radiation, under clear sky conditions. The daily average overall thermal efficiencies of the solar collector and the storage system during the experimental period were 76.39% and 93.17%, respectively. During the 181 days heating season, the solar panels collected 3922 kWh of energy which provided 47.74% of the total heat energy required to heat the greenhouse (8215 kWh). The hybrid system (biomass burning and solar energy systems) provided 46.585 kWh (85.90%) of the daily total heat energy required (54.230 kWh). While, the solar heating (solar and electric energy)  system with greenhouse 2 only provided 20.223 kWh (38.32%) of the total heat energy required (52.778 kWh). Due to the microclimatic conditions of the greenhouse were at or around the desired level, the sweet coloured pepper had have optimal vegetative growth rate, stem length, number of fruits being seated, and fresh yield.  The total costs per square meter of greenhouse were L.E. 57.01.The fresh yield of sweet coloured peppers was 6.595 kg/m², which sold by L.E. 79.14, consequently, the estimated return on capital was 38.82% per annum.