The federal government has been on a drive to economize on energy since Middle East oil embargoes of the 1970s. In more recent times, policies to reduce greenhouse gas emissions from the government’s buildings and vehicles have joined efforts to reduce spending on fuel. For the armed services, more efficient use of fuel and greater energy self-sufficiency are matters of readiness, agility and, ultimately, the ability to prevail in war. That’s why military leaders are undertaking a broad range of energy efficiency efforts encompassing installations, ground vehicles, ships and planes.