10 Things About Solar Energy

Taken from an article by Kristen Pope


1. The sun continuously strikes the earth with over 173,000 terrawatts of energy. This is an incredible amount, considering the fact that one terrawatt is equal to one trillion watts.


1. Spacecrafts have sported solar cells since the 1960s. It seems obvious that having a renewable energy source would be a huge benefit for an orbiting spacecraft. The Vanguard 1, which is the first orbiting satellite to utilize solar cells, is still in motion today—nearly 6 billion miles later.


1. Solar energy has grown at a rate of nearly 20% per year over the past 15 years.


1. The U.S. Department of Energy began to invest in solar power as far back as the 1980s. One of their earliest projects was called Solar One, located in California’s Mojave desert. In 1996, a second project—dubbed Solar Two—opened. This second facility utilized molten salt in order to store energy, as it is capable of storing heat at a very high temperature. This was the world’s first large-scale facility utilizing molten salt for solar energy storage.


1. Thermal energy storage is a key part of any solar energy system, since the sun doesn’t shine at night and less solar power is collected on cloudy days.


1. There are two main ways to capture solar energy: Solar photovoltaic (PV) cells and concentrated solar power (CSP). PV captures the sun’s rays and converts this solar energy directly into electricity. CSP transfers the energy to a receiver then utilizes mechanical energy (often turbines) to produce electricity.


1. The world’s largest solar energy project is currently in construction in the Mojave Desert of California. When complete, 350,000 mirrors will concentrate the sun’s energy onto boilers full of water. When these boil, steam will power a turbine and create electricity. Developers expect this project to power 140,000 homes.


1. One CSP plant can power up to 70,000 homes. The plants are, not surprisingly, concentrated in sunny locations, such as the deserts of southern California, Arizona, and Nevada. There are also isolated plants in Florida, Hawaii, and Northern California. Nearly a dozen of these plants are currently in use, with approximately eight more in development. They utilize a variety of technologies, including: troughs, fresnels, parabolic dishes, and tower/heliostat combinations.


1. The U.S. and Spain are currently the only two nations that have significant CSP capacity. Many other nations, however, are working to develop CSP resources and capacity.


1. By 2060, up to one third of the world’s energy could be supplied by solar energy, according to the International Energy Agency.