In typical fashion, the U.S. Congress passed a suite of last-minute tax laws last night, including an extension of the Treasury Grant Program (TGP) for renewable energy project developers.

Trade groups in Washington have been pushing hard for an extension of the program, which provides a cash payment of up to 30% of equipment costs in place of the Investment Tax Credit. The grant program was responsible for a large portion of the renewable energy projects built throughout the U.S. in 2010. Originally passed as part of the 2009 stimulus package, the TGP was supposed to expire at the end of December.

Because there are still a limited number of financial institutions able to finance projects by taking advantage of tax credits, the TGP has opened up new sources of capital for project developers. According to the Solar Energy Industries Association (SEIA), the grant program spurred over 1,100 solar projects and $18 billion dollars of investment in 2010.

“This program has successfully created thousands of jobs and opportunity in all 50 states for construction workers, electricians, plumbers, contractors that have struggled in this harsh economic climate,” said SEIA President Rhone Resch in a statement.

While the wind industry saw a significant drop in installations compared to 2009, the grant program helped keep thousands of MW on the table for 2010 and 2011. American Wind Energy Association CEO Denise Bode projected a loss of tens of thousands of wind jobs in 2011 without an extension of the TGP.

The program was also beneficial to many geothermal companies. According to the Geothermal Energy Association (GEA), between 500 and 700 MW of geothermal projects may come to fruition in 2011 and 2012, with most of those taking advantage of the grant. Without the TGP, many of those projects would not have financial backing.

“This extension is a substantial benefit to new geothermal power projects...this provision will greatly facilitate their ability to obtain the several billion dollars of capital investment needed to move them forward,” said Karl Gawell, executive director of the GEA in a statement this morning.

The renewable energy industry has been calling for an extension of the TGP all year. With no chance of getting a price on carbon or a federal renewable energy target, this was the one piece of legislation that had a shot at passing.

The TGP was passed as part of an $858 billion tax bill that extends Bush-era tax breaks to individuals and businesses. This was the one legislative vehicle that offered the possibility to get the program through before the end of the year. Industry trade groups worked overtime to put the TGP in the Senate version of the bill last week.

In addition to the TGP, the bill provides a retroactive tax credit to biodiesel producers for $1 per gallon, a $0.50 per gallon credit for ethanol producers and (much to the chagrin of Brazilian ethanol producers) a $0.54 tariff on important ethanol.

The Senate passed the legislation earlier this week. After rancorous debate, the House passed the bill last night. The tax package now goes to President Obama, who is expected to sign it into law later today.