This free online course asserts that solar energy, which is renewable and obtained from the use of electromagnetic radiation from the Sun, is sufficient to meet the world’s energy needs. We investigate how solar radiation reaches the earth and has long been used by humans through evolving technologies. We explain how the Sun’s energy can be collected by photoelectric cells, heliostats or solar collectors before being transformed into electrical or thermal energy, thus potentially solving some of the world’s energy problems. This course explores that potential as we study what happens to the Sun, its radiation and how it relates to the Earth in the form of a wide range of phenomena related to solar energy’s absorption and release.

We then cover the importance of maintaining a delicate balance of CO2 in the atmosphere and how increased emissions can harm humanity and the environment. We unpack how solar energy intake can be affected by geographical location, season and time of day. The course breaks down the electromagnetic, solar and visible spectra before delving into the relationship between the temperature of the Earth and black-body radiation and wavelength.

The course then examines the use and characteristics of a solar cell based on the p-n junction, the fundamental structure of semiconductors. We go into the construction and efficiency of different types of solar cells, which include ‘tandem’ solar cells that can connect in series to increase the overall efficiency of the photovoltaic cell. We discuss the advantages of hydrogen production and photocatalytic water-splitting over electrolysis. The course then moves on to the recombination of electron holes, photocatalysts that convert solar energy into chemical energy on the surface of a catalyst or substrate, consisting of a semiconducting material that accelerates the speed of reaction. This course is aimed at those who want to learn a little more about solar energy and the opportunities it offers as a source of clean energy. It also suits anyone working in the energy sector who wishes to improve energy processes and equipment performance as they seek more innovative ways to harness the incredible power of the Sun.