This unit is one of a series developed by the Australian Science Education Project (ASEP) for use by students at the junior secondary level (grades 7-10) in Australian schools. The unit is a trial version dealing with solar energy, and may be used independently or integrated into a sequential program with other units. All students complete the activities in the core section of the unit, and then select from seven optional sections according to their interests and levels of cognitive development. This allows students to progress at different rates and at different levels of operation. The unit is designed to acquaint students with the importance of radiant energy from the sun as the original source of most of the earth's available energy. Topics such as energy transformation, the spectrum, photosynthesis, the role of the earth's atmosphere, uses of solar energy, and the earth's limited energy resources are covered. Wherever possible, first-hand experience is gained through student activities and experiments. A Teacher's Guide provides an overview of the unit, an equipment list, references and audiovisual materials, summarizes the objectives, and relates the core and each optional section to the appropriate reading levels and stages of development of the students. (JR)