Analytical and numerical study to assess the solar flux on a heliostat based central receiver

Abstract

The objective of the study is to estimate the solar flux for a heliostat based central receiver system. Analytical and Monte Carlo ray tracing based numerical simulations have been performed to assess the solar flux on a fixed target. The simulations have been performed using a freeware Sol Trace released by NREL (National Renewable Energy Laboratory). A flat heliostat of (1×1 m2), which is located 10 m far from the base of a 15 m high tower, on which, (1.6×1.6 m2) target is considered for the study. Sketch up has been used for designing the model. NIT Warangal, India with a longitude 79.5 ° E and latitude 18 ° N is considered to predict the solar flux on the target on 1st April from 9 am to 5pm at the interval of one hour. Result obtained from analytical and numerical methods are compared in terms of solar flux on the target. It is observed that maximum variation between the two methods is within ±5%. The study could reveal that the field losses play an important role in the heliostat based central receiver system.