Studies on hybrid solar collector with water driven solar tracking unit

Abstract

ABSTRACT The current solar concentrating collectors can be driven by water gravity without using a torque motor. It saves the electricity required to drive the large solar concentrating collectors. The objective of this study is to simulate and experimentally evaluate a novel hybrid system that combines photovoltaic and thermal technology with a hydro-powered solar tracking unit. The device consists of a hybrid solar collector, which is a multi-reflector compound parabolic collector (MRCPC), an evacuated tube receiver, photovoltaic (PV) panels, and a tracking system. The tracking mechanism attaches the tracking weights to both sides of a chain and sprocket. This hybrid collector rotates around its axis by adjusting the weight of the water in each of the monitoring weights. The system integrates a 12-volt direct current pump (operated by photovoltaic power) for tracking, with flow rate control. A mathematical model is developed and applied to determine the ideal tilt angle for a solar concentrating collector. The model was then used to compare the actual tilt angle and minimize errors in tracking. An experimental investigation used a flow rate of 0.8 LPM. The study achieved a mean tracking error of 2.05º, a maximum thermal efficiency of 43.65%, a maximum solar PV efficiency of 11.30%, and a maximum overall efficiency of 29.81%. An analytical method was developed to simulate the collector’s outlet temperature.