History of Solar in Australia Solar power is one of the most abundant energy sources on Earth, and it has been used by humans for thousands of years. Solar energy was first used for practical purposes in the late 19th century when French physicist Augustin Mouchot patented a solar-powered engine. However, it was not until the 1950s that solar technology began to be used on a large scale. Solar cells were initially used in spacecraft and satellites, but they soon found their way into consumer products like calculators and watches.