Renewable energy sources are fast emerging as more reliable supplement of conventional energy sources. Among the various renewable sources, solar energy is most sought after in today's world. Solar PV modules when installed in outdoor environments suffer from various factors which are generally unaccounted in laboratory testing. Energy generation from solar collectors is primarily dependent on the amount of incident radiation on their surfaces. Soiling on modules is known to reduce the transmittance of incident rays to solar cell and cause significant output power degradation. Soiling is closely associated with the various factors such as module tilt angle, site-specific climate, outdoor exposure period, humidity, wind speed, dust characteristics and material properties. This experimental work is aimed to study the transmittance losses encountered by solar PV modules and the corresponding power degradation. The experimental results show an alarming reduction in transmittance as high as 69.06% over the dry study period experiencing no rain. The power of dusty solar module decreases by 29.76% compared to the module cleaned on daily basis. Dust deposition density on the PV module accounted to 9.6711 g/m 2 over the study period.