a b s t r a c tThis paper discusses theoretical and indoor experimental studies of a bi-fluid type photovoltaic/thermal PV/T solar collector. 2D steady-state analysis was developed and computer simulation was performed using MATLAB. Experiments were conducted for steady-state analysis under the solar simulator at Solar Energy Research Lab UiTM Perlis, Malaysia. The test includes all three modes of fluid operation under the same PV/T system, namely: the air mode, the water mode, and the simultaneous mode of water and air. The simulation results were validated against the experimental results using three methods of error analysis: root mean square percentage deviation (RMSPD), mean absolute percentage error (MAPE), and coefficient of determination (R 2 ). On average, the MAPE, RMSPD, and R 2 computed for the fluid output temperature are approximately 0.92%, 1.19%, and 0.98, respectively. Thus, we concluded that the simulation and experimental results are in good agreement. The PV/T collector designed in this study has a variety of applications as it can be operated in three different modes of fluid operation, and the theoretical model is useful in modelling all three modes without further modification.