Sunpath, Internet-based solar engineering education

Software that models the availability of solar radiation and the electrical performance of solar cells and photovoltaic systems has been developed and made available via the Internet at the following site: http://engn.anu.edu.au/solar/Sun/. The software has been conceived as an educational aid to be used in secondary and tertiary education. A visually attractive, user friendly interface, with special emphasis on the graphical presentation of the results, hides the complexities of theoretical modelling from the user. There are two separate programs, the first one is a virtual reality representation of the apparent motion of the sun in the sky in three dimensions. The main learning points are the length of the day, the sun's elevation, the projected shade, the differences between the seasons and the influence of the latitude. The second program models the performance of photovoltaic systems using average climatological data for the most representative Australian locations. It is possible to select the size of the PV array adding modules in series and parallel and calculate the energy produced over a day, a month or a whole year. Important learning points are the effects of the PV module inclination, light intensity and temperature on the module output, and the size of the PV array required to produce a given amount of energy.