It is billed as the world’s largest factory for making solar energy panels and could put metro Toledo on the high-tech map with its promise of making production of electricity from sunlight as economical as from other sources.But nearly a year and a half after investors such as Wal-Mart, Inc., heir John Walton spent $16 million to build the plant in Perrysburg’s Cedar Business Center, no panels have been sold. And insiders of Perrysburg-based First Solar LLC disagree about the likelihood the firm will reach its lofty goal. Toledo inventor and philanthropist Harold McMaster, who founded the firm in 1986 and helped design its manufacturing equipment, is not happy with the plant’s progress. “I can’t say I’m optimistic it will be up and operating,” said Mr. McMaster, an 85-year-old glass industry pioneer. “They do not have the right leadership,” added Mr. McMaster, a partial owner of First Solar and member of the firm’s board of managers. Company President Michael Ahearn, after first stating that Mr. McMaster “doesn’t participate in operations or in setting policy and direction,” conceded that the factory has encountered unexpected problems.