As work on the Transportation Bill progressed in the Senate Tuesday, two amendments that would have extended tax incentives for renewable energy sources were defeated.

An amendment offered by Sen. Debbie Stabenow (D-MI) failed on a tie vote of 49-49, since 60 votes were needed for passage. The amendment would have extended a variety of incentives, including the Cellulosic Biofuels Producer Tax Credit (PTC) the Accelerated Depreciation Allowance for Cellulosic Biofuel Plant Property, and the Alternative Fuel Infrastructure Tax Credit available to blender pumps and other ethanol fueling infrastructure, the Production Tax Credit (PTC) for wind and grants in lieu of tax credits to eligible solar projects, all of which are due to expire at the end of this year.

“Unfortunately the Senate missed an opportunity to put to bed the pressing need to extend expiring tax incentives for cellulosic biofuels and other sources of domestically produced clean energy,” said Advanced Ethanol Council Executive Director Brooke Coleman. “Echoing the 49 U.S. Senators who voted for the Stabenow amendment today, we cannot afford to miss any more opportunities to get this done.”

The measure would have also extended the $1 per gallon biodiesel tax incentive, which expired at the end of last year, through the end of this year. Another amendment offered by Senator Pat Roberts (R-KS) that would have extended the biodiesel tax credit was also defeated. “We thank Sen. Stabenow and Sen. Roberts for including biodiesel in their amendments, and we urge Congress to break this partisan gridlock and find a way to enact policies like the biodiesel tax credit that have strong bipartisan support,” said Anne Steckel, vice president of federal affairs for the National Biodiesel Board.

While the extension amendments failed to pass, an amendment to repeal most of the same tax incentives by Sen. Jim DeMint (R-SC) was also defeated in the Senate. DeMint’s amendment would have repealed tax credits for the wind, plug-in vehicles, and renewable fuels, but would have also addressed some taxes for fossil fuels. It failed by a much more resounding vote of 72-26.