In this paper, we propose a new application of irradiance estimate for photovoltaic (PV) applications. Maximum power point (MPP) operating strategy for PV system is developed using monthly irradiance estimate based duty cycle control. Duty cycle of DC -DC converter is calculated using monthly average irradiance (G(av)) and average of maximum irradiance (G(max,av)) received at Pilani during 2002-2011. Designed PV system operates at 60-95% of MPP throughout the year with these monthly irradiances based duty cycle operations. MPP of 71.6% and 66.81% is observed for January and July months respectively when the model is validated for weighted mean of maximum power point (w(MPP)) operation. Further, a % MPP of 98.21 is achieved when proposed strategy is tested at short interval irradiance estimate based duty cycle control. Extensive simulation using MATLAB/SIMULINK is carried out to observe the operating points of PV system under dynamic changing irradiances levels. Experiments using solar array simulator (SAS) are performed to validate the simulated results. (C) 2016 Elsevier Ltd. All rights reserved.