The History of Solar Panels
For the last century and a half, inventors have been working hard to make improvements in the efficiency and aesthetics of solar technology.
Solar energy technology began with a young physicist in France, Edmond Becquerel. In 1839, Becquerel observed and discovered the photovoltaic effect. This is the process that produces a voltage or electric current when exposed to light or radiant energy. A few decades later, French mathematician, Augustin Mouchot, began registered patents for solar-powered engines in the 1860s. All around the world inventors were inspired by the patents and began filing for patents on solar powered devices as early as 1888.
In 1883 New York inventor Charles Fritts created the first solar cell by coating selenium with a thin layer of gold. Fritts reported that the selenium module produced a current that was continuous, constant, and of considerable force. This cell achieved an energy conversion rate of 1 to 2 percent, but most modern solar cells work at an efficiency rate of 15 to 20 percent. While it was only a small amount of energy, this was the beginning of photovoltaic solar innovation in America.
A few years later in 1888, Edward Weston received two patents for solar cells. For these patents, Weston proposed “to transform radiant energy derived from the sun into electrical energy, or through electrical energy into mechanical energy.” Light energy is focused by a lens onto the solar cell. The light heats up the solar cell and causes electrons to be released and current to flow. In this instance, light creates heat, which creates electricity. This is the reverse of the way an incandescent light bulb works, converting electricity to heat that then generates light.
Also in 1888, Russian scientist Aleksandr Stoletov created the first solar cell based on the photoelectric effect. This is when light falls on a material and electrons are released. In 1894, American inventor Melvin Severy received patents for what was basically early solar cells based on the discovery of the photoelectric effect. Severy also received a second patent in 1889 which was also meant for using the suns thermal energy to produce electricity for heat, light, and power.
Almost a decade later, American inventor Harry Reagan received patents for thermal batteries which are used to store and release thermal energy. This battery was invented to collect and store heat by having a large mass that can heat up and release energy. Systems today use this technology to generate electricity by conventional turbines. In 1897, Reagan was granted a patent for an application of solar heat to thermo batteries. His invention was a means of collecting, storing, and distributing solar heat as needed.
In the 1950s, Bell Laboratories realized that semiconducting materials were more efficient than selenium. They created a solar cell that was 6 percent more efficient. While it was considered the first practical device for converting solar energy to electricity, it was still cost prohibitive for most people. Silicon solar cells are expensive to produce, and when you combine multiple cells to create a solar panel, it’s even more expensive for the public to purchase. The University of Delaware is credited with creating one of the first solar buildings, “Solar One,” in 1973. The construction ran on a combination of solar thermal and solar photovoltaic power. The building didn’t use solar panels; instead, solar was integrated into the rooftop.
In the 1970s, an energy crisis in the US began and Congress passed the Solar Energy Research, Development and Demonstration Act of 1974. The government was more committed than ever to make solar power a more viable and affordable option for the public. After the debut of “Solar One,” people saw solar energy as an option for their homes. Growth slowed in the 1980s due to the drop in traditional energy prices. But in the next decades, the federal government was more involved with solar energy research and development, creating grants and tax incentives for those who used solar systems. According to Solar Energy Industries Association, solar has had an average annual growth rate of 50 percent in the last 10 years in the United States, largely due to the Solar Investment Tax Credit enacted in 2006. Installing solar is also more affordable now due to installation costs dropping over 70 percent in the last decade.