There is a great potential for solar power utilization in the Eastern part of Saudi Arabia by employing solar photovoltaic (PV) modules. Dust accumulation on the surface of solar PV modules, mirrors, reflectors and other solar collectors is of great concern due to occasional to frequent dust storm in the gulf region. The performances of such devices are significantly affected by dust accumulation. This paper presents the result of a study on the effect of dust accumulation on the power output of solar PV modules in the Eastern province of Saudi Arabia. The study indicates that power decrease by as much as 50% can be experienced for solar PV modules that are left unclean for a period of over six months. Solar tracker improves power output and helps reduce dust accumulation effect by 50% at off-peak time. (C) 2013 Elsevier Ltd. All rights reserved.