The U.S. Senate on Tuesday voted not to approve two amendments to a transportation bill that would have boosted alternative energy sources. The wind industry is desperate to get the production tax credit renewed. It provides a 2.2 cents per kilowatt subsidy, making it competitive with the lowest cost power sources, but it failed 49-49. The NAT GAS Act, championed by billionaire T. Boone Pickens, would have created subsidies to encourage the use of natural gas as an automobile fuel. It failed 51-47. Both would have required 60 votes.