A solar drying system was designed, constructed and tested for drying of seaweed. Seaweed is a potential source of renewable energy, and it can be converted into energy such as biofuel oil, biodiesel and gas. Red seaweed was dried to the final moisture content of 10% from 90% w.b in 15 h. Drying kinetics of red seaweed were investigated and obtained. The nonlinear regression procedure was used to fit three different drying models. The Page's model clearly showed a better fit to the experimental data between Newton's model and Henderson and Pabis model. The Page's model was resulted in the highest value of R-2 and lowest values of MBE and RMSE. At average solar radiation of about 500 W/m(2) and air flow rate 0.05 kg/s, the collector, drying system and pick-up efficiencies were found about 35,27 and 95%, respectively. This study was performed with energy analysis and exergy analyses of the solar drying process of red seaweed. The specific energy consumption (SEC) of 2.62 kWh/kg was obtained. Moreover, the exergy efficiency of solar drying ranged from 1% to 93%, with an average of 30%. The values of improvement potential were found to be in the range of 0.3 and 630W, with an average of 247W. (C) 2013 Elsevier B.V. All rights reserved.