“So long as the sun shines, man will be able to develop power in abundance,” said Edison. This idea has passed from generation to generation. The display will showcase the imaginative ideas of what scientists thought solar energy could do and can do, and will feature objects that demonstrate uses for the sun’s rays as well as how sunlight can be converted into electricity. Hal Wallace, the museum’s curator of electricity, said “This exhibit aims to help museum visitors understand the history of solar energy use in America and the Experimental silicon P/N junction, 1940 Engineer Russell Ohl worked at Bell Labs during the 1930s. While researching semi-conductors—materials whose ability to conduct electricity can be manipulated—he found positive (P) and negative (N) regions created by impurities in his silicon sample. The barrier between the regions, called a P-N junction, prevented electrons from moving—until he exposed the silicon to sunlight. Then electrons crossed the junction and generated a current, converting sunlight into electrical energy. The silicon rod mounted in this reflector contains a P-N junction across the center. Ohl’s discovery contributed to the invention of both solar cells and transistors. “So long as the sun shines, man will be able to develop power in abundance . . .” —Thomas Edison, 1896 issues involved in evaluating solar ener-gy as a source of electric power for the future.” The display also will look at the devel-opment of “photovoltaics” the term for generating electricity from light using solar cells. Engineers have used solar cells to power satellites on long-term space missions because of their reliability. The function of a solar cell is to capture a ray of light and convert it into electricity. On Earth, photovoltaics can be used to power devices such as household appli-ances, various vehicles, communication relays and even entire buildings in a cost-effective, reliable and efficient manner. “Solar on the Line” complements another new exhibition, “Giving in Amer-ica,” which examines the role of philan-22 SPRING 2017 SOLAR TODAY (To the right) Solar heater patent model, 1880 James P. Mauzey of Blackfoot, Montana Territory, patented a solar heater in 1880. His pat-ent called for a movable frame to track the sun and adjust-able glass or metal reflectors “for concentrating and focus-ing the rays . . . for any desired purpose.” Pulling a curtain over the reflectors turned the unit off. COURTESY OF THE NATIONAL MUSEUM OF AMERICAN HISTORY Copyright © 2014 American Solar Energy Society. All rights reserved.