Terrestrial use of PV has been growing steadily. By 1983, 50 000 000 calculators with small amorphous silicon devices were in use worldwide; 5000 homes and over 200 water pumps were powered by PV in the United States alone; the one MW ARC0 Solar central-station plant near Hesperia, California was in operation; and the 6.5 MW Carrisa Plains station, also in California, was in advanced stages of planning. Today, utility interest in PV is increasing and is exemplified by the PVUSA project, which will be discussed later.