History of Home Solar Energy

The history of home solar energy begins at the dawn of the industrial revolution. Although early uses were limited to science and government, solar energy is quickly becoming a practical reality in today's homes.

Using the sun's light to create electricity is called the photovoltaic (PV) process. The basic concept is that photons from the sun's light excite the atoms in certain substances, causing them to release electrons. The release of electrons generates and electrical current.

Discovery Of Photovoltaics
In 1876, William Grylls Adams and Richard Evans Day discovered that selenium generates electricity when exposed to sunlight. They were building on pioneering work done by the French scientist Edmond Becquerel. Selenium solar cells didn't generate enough electricity to be practical, but they showed that solar power was possible.

In 1953, scientist at Bell Laboratories created the first silicon-based PV cell. The silicon power cell was much more efficient than previous types. Early silicon cells created electricity at 2% efficiency. Although this was an improvement, PV cells were too expensive for commercial use.

Early Use In Space
In the second half of the 1950s, government scientists determined that PV cells would be the perfect power source for satellites and space vehicles. This sudden demand for PV cells caused a jump in development and efficiency. Solar cells at the time produced electricity at 6% to 8% efficiency.

Energy Crisis (Part One)
In the 1970s, world politics and an energy crisis in the US pushed alternative energy to the forefront. The demand for PV cells jumped again and manufacturers doubled energy efficiency to about 15%.

PV cells were used mostly in experimental power stations, but also began to see use as home solar energy systems. Early residential solar energy use was limited to remote homes and curious do-it-yourselfers.

Energy Crisis (Part Two)
In the past decade, growing concern over energy independence and future shortages has again thrust home solar energy into the spotlight. Improved production techniques have increased efficiency to over 30%. Oil and coal power plants achieve 30% to 40% efficiency, making PV cells a viable alternative for the first time.

Home solar energy systems have entered the mainstream. Many states now allow home solar energy users to sell back excess electricity to their local power companies. Recently, the state of California has mandated that new subdivision developments offer home solar energy systems as a standard option.

Looking Ahead
Nanotechnology and advanced research promise improvements in efficiency and lower production costs. The US Department of Energy predicts that PV cells will reach 65% efficiency in the near future. That level of efficiency, coupled with lower production costs could be the key to making home solar energy systems a standard for us all.