Speech for How Solar Energy Works
Specific purpose: To inform listeners how solar energy offers a beneficial source of renewable clean energy
Central idea: Using solar energy offers a realistic source of clean energy, but governments and people must be willing to make the necessary changes to use it.
Informative speech: How solar energy works
Solar energy is perhaps the oldest form of power ever used by human beings. People have used the energy derived from the sun to light their homes; grow crops; tell time; and guide their lives since human civilization began. However, solar energy has only recently become regarded as a potentially feasible way of dealing with the nation’s energy crisis. This paper will describe how solar energy works, why it is so potentially beneficial for humankind, and some cultural obstacles to using solar energy.
On a very basic level, houses can be redesigned to better use solar heat. “Simple design features such as properly orienting a house toward the south, putting most windows on the south side of the building, skylights, awnings, and shade trees are all techniques for exploiting passive solar energy” (How solar energy works, 2012, Union of Concerned Scientists). Large, flat boxes painted black on the inside and covered with glass called solar collectors can be used to trap and collect solar energy to light and heat a building. On a wider scale, using mirrors and lenses to concentrate the rays of the sun can be used to actually power industrial applications. This can be achieved through the use of “parabolic troughs — long, curved mirrors that concentrate sunlight on a liquid inside a tube that runs parallel to the mirror. The liquid, at about 300 degrees Celsius, runs to a central collector, where it produces steam that drives an electric turbine” and can produce heats up to 3,000 Celsius (How solar energy works, 2012, Union of Concerned Scientists). A similar type of application, that of parabolic dish concentrators, generate even more heat because their design enables more concentrated focus of the energy that is created through the shape of the dish. Another promising source of solar energy is that of photovoltaics (PV) systems connected to the electric grid. “The most important components of a PV cell are two layers of semiconductor material generally composed of silicon crystals” which creates an electric spark when exposed to sunlight (How solar energy works, 2012, Union of Concerned Scientists).
Because solar energy is an inexpensive and renewable source of energy, there has been a great deal of interest in using it in many countries. For example, the governments of Germany and Japan have offered incentives for researching solar energy to scientists and to businesses and consumers for using it. “In 2009 alone, Germany installed 3,806 megawatts (MW) of PV solar energy capacity” more than eight times that of the United States (Top 10 countries using solar power, 2013, One Block Off The Grid). Germany has been particularly successful due to a “combination of a proven feed-in-tariff (FiT) scheme, good financing opportunities, a large availability of skilled PV companies, and a good public awareness of the PV technology” (Top 10 countries using solar power, 2013, One Block Off The Grid). But knowledge of the value of solar power has even spread to smaller countries: in Israel and Cyprus, more homes have solar water heaters than do not because of new building requirements (How solar energy works, 2012, Union of Concerned Scientists).
However the United States, despite its technical sophistication and wealth, lags behind. During the late 1970s and 1980s during the energy crisis, there was a rise in interest in solar power, particularly in warmer weather areas. But as fuel costs declined and tax credits expired, so did the desire to implement the technology (How solar energy works, 2012, Union of Concerned Scientists). But this is changing due to changes in government policies. “The cap on the federal solar tax credit was lifted in 2009, promoting growth in this industry. Despite the recent recession, the U.S. market for residential solar panels doubled in 2009, and increased 37% from 2008” (Top 10 countries using solar power, 2013, One Block Off The Grid).
It remains to be seen if the change in U.S. consumption habits regarding solar power is a fad or a true shift in how solar power is viewed. Regardless, there is little question that increased use of solar energy is safer and less damaging to the environment than using non-renewable fossil fuels, and cheaper once the initial investment in the technology is made. Hopefully, we will come full circle as a society and someday be able to use the form of energy that heated and lit our ancestor’s homesâ€¦only in a way that will still support our modern, technological lifestyles.
How solar energy works. (2012). Union of Concerned Scientists. Retrieved:
Top 10 countries using solar power. (2013). One Block Off The Grid. Retrieved: