President Obama last week nominated Miranda Ballentine, a top sustainability and renewable energy official for Wal-Mart Stores, to become assistant secretary of the Air Force for installations, environment and logistics, continuing the administration’s preference to select individuals with a background in energy to lead each service’s installations office. Kathleen Ferguson has been the acting assistant secretary since last March when Terry Yonkers stepped down. Ballentine has been the director of sustainability, renewable energy, sustainable facilities and stakeholder engagement for Wal-Mart Stores since 2008. Previously, she was vice president of investor analysis, chief operating officer and senior consultant for David Gardiner and Associates, according to a White House press release. In 2004, she served as the director of operations, assistant treasurer, and a board member for Environment2004. Ballentine was the operations director for the Solar Electric Light Fund from 2001 to 2004.