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Solar Thermal Installers and Technicians


Solar energy use dates back to early civilizations. The ancient Greeks designed their homes to take advantage of the sun’s warmth and light by having the structures face south to capture more heat in the winter. This “passive solar energy” technology is still used today. The ancient Romans improved on these designs by adding more windows to the south side of homes and by putting glass panes in the windows, increasing the heat and light into buildings. The Greeks and Romans were among the first to use mirrors to reflect the sun’s heat to light fires.

From the 1500s to the 1800s, inventors and scientists experimented with solar energy collection and devices. Leonardo da Vinci built a rough solar energy collector in 1515. Swiss scientist Horace de Saussure built the world’s first working solar collector in 1767. French physicist Henri Becquerel discovered the photovoltaic effect in 1890; this is the physical process through which a photovoltaic cell converts sunlight into electricity.

In the following years, many scientists studied photovoltaic technology, but it was not until 1954 that the U.S. company Bell Labs developed the first solar photovoltaic device that produced a useful amount of electricity. Architect Frank Bridgers used photovoltaic technology in 1956 to design the Bridgers-Paxton building, the world’s first commercial office building featuring solar water heating and passive design. In 1958 the Solar Energy Industries Association reported that, “solar cells were being used in small-scale scientific and commercial applications, including the space program.”

The energy crisis in the 1970s caused the U.S. government to increase research on renewable energy sources, including solar power. It was cost-prohibitive to use solar power on a large scale at that time, however, photovoltaic cells began to be used in remote applications, especially in the telecommunications industry. The first solar electric generation station plants were built in California’s Mojave Desert from 1984 through 1990, and are still in operation today.

Costs to develop solar power technologies have decreased in recent years. The U.S. government's focus on solar energy varies depending upon the state of the economy and the administration. For example, in 2020, the economic slowdown due to the coronavirus pandemic has impacted many industries, including the solar energy industry. Generally, state and federal government policies encourage the growth of the industry as a means to help the United States gain energy independence from foreign countries and create energy technologies that are more environmentally friendly.

In 2019, solar energy comprised 9 percent of all renewable energy in the United States, an increase from 5 percent in 2015, according to the Energy Information Administration. Its potential as a major energy source is largely untapped. 

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