March 28, 2005 March 28, 2005 REDLANDS, Calif., March 28, 2005—Though it produces only a small portion of the electricity generated by Southern California Edison’s power plants, SCE’s Mill Creek No. 1 hydroelectric plant holds a special place in the company’s history and played a significant role in Redlands’ development. A hydroelectric plant generates electricity by using the gravitational energy of falling water from a higher to a lower elevation. Mill Creek was the first power plant in the world to employ alternating current to generate “three-phase” electricity, the type of power widely used today throughout the world for commercial purposes and to transmit electricity over long distances. Mill Creek No. 1 began operating on Sept. 7, 1893, supplying power to the immediate area, where customers had begun using motors to irrigate Redlands’ many orange groves, and to major customers such as the Union Ice Company, which provided refrigeration to cool the area’s No. 1 cash crop—oranges. Direct current (DC) electricity was widely used in those days, but DC-generated power could travel only a few miles over the wires carrying the electricity. Single-phase alternating current (AC), which had recently been invented by Nikola Tesla, had the potential for long-distance transmission, but AC generators and motors were still untested. Technological advancements on the AC motor by a brilliant young electrical engineer named Almarian Decker made possible sending electricity over greater distances possible. Three-phase electricity generation ultimately revolutionized the electric utility industry. Using the water that flows through Mill Creek Canyon and into the Santa Ana River, Mill Creek No. 1 can generate one megawatt of electricity, enough energy to power approximately 1,000 homes. For comparison’s sake, SCE’s Mountainview project, a natural gas-fired facility currently under construction in Redlands expected to go online in 2006, will generate approximately 1,050 megawatts, enough to power approximately one million homes. “Mill Creek stands as a landmark for the electrical industry, Edison, and the Redlands community,” said Beverly Powell, SCE’s region manager for public affairs. “It was a first-of-its-kind power plant, and it played a crucial role in the development of Redlands and the Inland Empire, which is the fastest growing region served by Edison.” # # # An Edison International (NYSE:EIX) company, Southern California Edison is one of the nation’s largest electric utilities, serving a population of more than 13 million via 4.6 million customer accounts in a 50,000-square-mile service area within central, coastal and Southern California.