Sunlight and solar cells: teaching digital design and communication through the development of a simple monitoring station

Abstract

A method is described for building a cost effective digital circuit capable of monitoring the solar radiation incident upon a remote solar cell. The circuit is built in two sections, the first, digitises the analogue voltage produced by the solar cell at a remote location and transmits the received signal to the second receiver circuit which relays the information to a computer for storage. The activity introduces students to simple programming techniques required to communicate with a computer serial interface, and to analyse binary signals for accurate interpretation of the induced solar cell voltage resulting from exposure to sunlight. The activity can be extended by investigating the influence of solar cell tilt angle with respect to solar position, studying the effect of seasonal solar altitude differences and noting the effect of cloud on the radiation received. The completed project provides schools with their own solar radiation monitoring station which can be used for future studies of weather and climate.