Leonardo da Vinci proposed sunlight as the energy source for a large solar furnace. His notes describe arranging many mirrors so they could concentrate sunlight and produce intense heat.
A solar furnace focuses radiant energy onto a small target area. Concentrating the rays increases the temperature at that point, allowing the heat to melt or soften materials and potentially support industrial processes. Leonardo’s proposal belongs to early experiments with concentrated solar power.
The concept was not a modern photovoltaic system. Photovoltaic panels convert light into electricity, whereas a solar furnace uses mirrors or lenses to convert sunlight into concentrated heat.
Leonardo’s design was ambitious for the Renaissance because it required accurate reflective surfaces and careful alignment. Later solar furnaces became practical with improved mirrors, tracking systems, and engineering. The principle remains in use today for high-temperature research and materials processing.