A four-year investigation has concluded that officials of the solar company Solyndra misrepresented facts and omitted key information in their efforts to get a $535 million loan guarantee from the U.S. government. Solyndra was the first company to get federal loan guarantees under a program that was created in 2005 and expanded by President Barack Obama’s 2009 economic stimulus package. The company’s failure soon after receiving the loan guarantee likely will cost taxpayers more than $500 million. Republicans and other critics cite it as an example of wasteful spending under the stimulus program. The report by the Energy Department’s inspector...