Modern solar panels were invented in 1954, when researchers at Bell Telephone Laboratories demonstrated the first practical silicon solar cell. Daryl Chapin, Calvin Fuller and Gerald Pearson built a device that converted sunlight into electricity at roughly 6% efficiency.

Earlier discoveries led to that development:

Year Milestone Why it matters
1839 French physicist Alexandre-Edmond Becquerel discovered the photovoltaic effect. He showed that light could produce an electric current.
1870s to 1880s Scientists developed selenium-based photovoltaic cells. These were among the first devices to convert light directly into electricity.
1884 An early solar array was installed on a New York City rooftop. It showed that several solar cells could be combined into a panel-like system.
1954 Bell Labs developed the first practical silicon solar cell. The design became the basis for modern photovoltaic panels.
1958 Solar cells powered the Vanguard 1 satellite. The mission showed that solar cells could provide power for long-term space use.

What Is the Difference Between a Solar Cell and a Solar Panel?

A solar cell is a single photovoltaic device that converts sunlight into electricity. A solar panel, also called a photovoltaic module, connects multiple solar cells to produce more electrical power.

The date depends on what "solar panels" means:

  • 1839: Discovery of the photovoltaic effect.
  • The 1880s: Development of early selenium solar cells and panel-like arrays.
  • 1954: Development of the practical silicon solar cell used as the basis for modern solar panels.

For the technology used in modern solar panels, the answer is 1954.