In a single day, the sun provides enough energy to power the entire population of the globe for 27 years. The ability to harness this power was developed around 250 years ago, a mere time snippet compared to how long we’ve been using coal, wood, and gas.
In 1767, a Swiss scientist named Horace de Saussure constructed the first solar collector, a system he used to heat food and water. Over 120 years later, the first commercial patent for a solar hot water system was granted to Clarence Kemp of the United States. His system was purchased and installed in one-third of the homes located in Pasadena by 1897.
In 1839, a French physicist named Edmund Becquerel discovered how to generate electricity from solar energy. Nearly 40 years later, a photovoltaic cell was developed that operated at 1-2% efficiency, though it was unknown exactly how the process worked. It was not until Albert Einstein proposed the “photoelectric effect” in 1905 that the process began to be understood. The photoelectric effect is simply the process of high energy light packets striking the surface of a solid, liquid, or gas, resulting in the material emitting photoelectrons.
By 1908, a solar collector that resembles the technology we have today was invented by William J. Bailey, a British-born American of the Carnegie Steel Company. Approximately 4% efficiency was accomplished by the 1960s, with 11% achievable soon after. During this time, space agencies had seen the use of photovoltaic cells for use in satellites as they were durable and could provide consistent power to the technologies.
Unfortunately, fossil fuels remained more popular for several decades because of the high cost and poor efficiency of solar systems. However, fast forward to the twenty-first century with climate concerns and rising energy requirements, and solar power starts to receive the funding it deserves. Governments started to heavily invest in solar, and as the technology became 40% more efficient and cheaper to manufacture, it became more popular. The purchase cost has dropped from $200 per kilowatt 60 years ago, to $1 per kilowatt today, making solar affordable to many homes and businesses.
The solar industry has gone from strength to strength in recent years, with many governments offering rebates for those installing new solar systems. These cannot only provide cheap energy once the set-up costs are recouped, but they can also feed excess power to the grid, allowing energy companies to provide clean electricity to others.