Environment News Service: North America’s largest solar photovoltaic system is now up and generating power at Nellis Air Force Base in the sunny desert of southern Nevada. The $100 million solar power plant at Nellis will supply about 25 percent of the total power used at the base, where 12,000 people live and work. The 14 megawatt photovoltaic array will generate more than 30 million kilowatt-hours of electricity annually. Completed earlier this month, it was inaugurated with a ceremony at Nellis on …