Energy analytics company Opower has released its findings regarding the projected annual cost to charge an iPhone 5. The study was done under the "assumption that iPhone owners will recharge their device once a day for the entire year." This results in a yearly cost of about $0.41, or 3.5 kWh. It is very possible that the battery life on the iPhone 5 will prevent you from having to charge it everyday, which could save some additional money. The company also did a study on the Samsung Galaxy S3, which costs just $0.53 per year to charge.