People first used solar energy in the 7th century B.C.

As far back as the 7th century B.C., humans have been using sunlight to light fires with magnifying glasses. The Greeks and Romans also harnessed the sun's energy by using mirrors to light torches for religious ceremonies, known as "burning mirrors." The Chinese civilization also documented the use of mirrors for this purpose in 20 A.D. Sunrooms, which use large windows to direct sunlight into a concentrated area, were also a popular use for solar energy throughout history.

Examples include the Roman bathhouses and the south-facing abodes of the Anasazi in the 1200s A.D. In the late 1700s and 1800s, researchers and scientists successfully used sunlight to power ovens on long voyages and to create solar-powered steamboats. This shows that manipulating the power of the sun has been a common practice for thousands of years, even before the era of solar panels.