ABSTRACT

Performance evaluation of a Solar Organic Rankine System (SORS) for electricity generation was carried out to determine the suitability of the system based on local solar radiation conditions obtained in Calabar. Refrigerants R-1 13, R-141b, R-123, R-11, and R-142b were used for the modeling to present a wide range of options with regards to system efficiency and cost of operation. To determine the nature of local weather conditions, solar radiation data were used for a period of 10 years to ascertain monthly solar averages for the simulation. System performance evaluation was simulated with Engineering Equation Solver (EES) to predict the power output 1mm the system with the stated operating parameters. The results obtained shows power output in the system to range between 3.56 kW to 5.6 kW for an average location temperature of 28°C. Additionally, a techno economic evaluation of the system using the bare module cost for a heat input range of 20 kW ≤Q 45 kW, reflected a cost range of $52211 ≤ CT ≤$93751, $50861 CT≤ $88166, $53468 CT≤ $96441, $55567 ≤ $92752, and $54907 ≤ CT ≤ $86425, for R1 13, Rl4lb, RI 1, R123, and Ri42b respectively. Similarly, values of Net power output index (NPI) were plotted for the five refrigerants in order to assess, economically, their suitability and the refrigerant R11 appeared more suitable by virtue of its higher turbine output per unit cost. The NP! values for the considered refrigerants increased with increase in heat input which results from increased turbine output. Finally, the NPI values which averaged 0.5402W1$, 0.5153 W/, 0.5577W/$, 0.5494 W/$, and 0.5259 W/$, for R113, R141b, RN 1, R123, and R142b respectively, suggests the implementation of a SORS as practical, attractive and feasible for Calabar.