This video advises viewers who want to decrease energy consumption to take a lesson from a cat lying in the sun. The sun's energy, an engineering design professor explains, can be harnessed for human needs in three ways: convert solar energy to heat, heat hot water, or convert solar energy to electricity.
One example in the video focuses on how solar panels helped a school to decrease electricity costs, and taught students they could make a difference. Another is how a prison heated water for showers and laundry with solar panels. Both the school and prison significantly decreased energy consumption.
Solar energy can be captured and transformed for use in our everyday lives and homes. It's not just a modern idea. In ancient times Romans would cover the windows in their homes with glass or mica in order to trap the heat from the sun during the cold winter months. From the mid 1800s through the 1980s scientists concerned about depleting the earth's fossil fuels worked to invent and produce efficient ways of producing solar power.
Currently solar power is used in calculators, satellites, emergency road signs, and parking lot lights. Where the cost of stringing a conventional power line is high (such as for temporary road signs), solar can be a very cost-effective solution. Some homes even have solar panels as a means of producing some of their electricity.
Like homes with solar panels, the school and prison featured in this video cut the cost of electricity for themselves and the environment (e.g., with respect to their contributions to global warming). Why aren't we using solar energy more extensively?
Although research has improved the efficiency and cost of solar power in recent years, solar power is still less efficient than power from fossil fuels.
Due to the Earth’s natural tilt on its axis, the amount of direct sunlight that geographical locations receive varies with latitude. Locations near the equator are positioned at nearly ninety degree angles in reference to the sun, whereas locations at higher latitudes are positioned at much greater angles and receive far less direct sunlight. Therefore, the amount of solar energy that can be harnessed varies.
The amount of solar energy also varies with the time of year. For example, in Europe during the summer months, the northern hemisphere is tilted toward the sun, and therefore, the sun traverses a high, nearly vertical arch through the sky. As the Earth continues its revolution and the northern hemisphere tilts away from the sun, Europe experiences winter. During these months, the sun travels a flatter, more southerly path.
 Smith, C. (1995). History of Solar Energy: Revisiting Solar Power’s Past. Technology Review, 98(5), 38-47.
 Hug, Rolf. The Solarserver: Forum for Solar Energy. Retrieved August 19, 2008 from http://www.solarserver.de/solarmagazin/anlageapril2000-e.html
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