What do we learn about the use of solar energy in the USA?

Little by little, Americans are turning to solar power, tapping the strength of the sun for energy.
   Solar energy is only in its infancy, however, sunlight has already been used for heating or cooling homes and office buildings in the sunny south. Experts say all signs point to the birth of the solar energy industry. Right now, an increasing number of companies are selling solar collector panels to heat and cool homes or to heat water. The glass and metal panels cost from ＄ 100 to more than ＄ 500 each, and the three or four bedroom homes usually require a dozen or more. They look like sandwiches, or very narrow flower boxes, 3 to 6 feet in width, 8 to 10 feet long, and 4 to 8 inches thick. They are usually placed in rooftops. Nobody knows how many have been sold, and in addition, many people have built their own units. It has been estimated that solar power equipment will be a ＄ 1.3 billion industry by 1995, and more a million homes will use sunlight for heat, air conditioning or to generate electricity, both in the cities and in countryside.