In this paper, the drying characteristic of Empty Fruit Bunches (EFB) of oil palm is presented. The EFB, a waste of oil palm processing was used as the test sample and dried using a solar drying system that was built. The system used was comprised of six double-pass solar collectors with porous media in the second channel, which were connected in a series of three collectors in two banks and a drying chamber. Two conditions of the EFB sample were considered in the drying test; treated and untreated. A simple water washing treatment was used to treat the first sample to reduce its ash content whereas the second sample was untreated in its original condition. The EFB samples were dried until equilibrium moisture content below 10 mf wt% was reached, a condition required to achieve a number of purposes in energy applications and storage of biomass material. From the results obtained, it was found that the samples were successfully dried from an initial moisture content of 170.68 mf wt% to final moisture content of 3.85 mf wt% for the untreated sample and from 376.14 mf wt% to 4.36 mf wt% for the treated sample in 66 hours of solar drying.