At least one part of President Obama’s stimulus bill is having its intended effect: reinvigorating investment in wind energy. Since slowing down in the first half of 2009 after torrid growth in 2008, money is again flowing into the wind industry from all directions.

On Tuesday, the U.S. Departments of Energy and Treasury handed out the first round of grants from a federal program created to induce investment in renewable energy. The program has distributed over $500 million in grants thus far, with the vast majority going to wind projects. These stimulus funds will provide a huge boost to the wind industry, giving momentum to projects that slowed during the economic downturn.

The program functions by providing a cash rebate equal to 30% of total investment as soon as the wind project begins producing energy. The grants are available to projects that begin construction by the end of 2010 and start operating by December 31, 2012.

However, the government is not the only one suddenly financing wind projects—now Wall Street is once again entering the fray. On Monday, the Wall Street Journal reported that within the last month, Morgan Stanley and Citigroup have each invested $100 million in separate wind farms. The banks, too, are being spurred by the stimulus money, seeing it as a deal too good to pass up.

All this talk of new development brings to mind a report issued earlier this year by the Energy Information Administration. The report, which predicted the country’s energy outlook years into the future, projected that wind energy would make up 5% of all electricity generated in the United States by the year 2012. Five percent is a huge number—it’s four times more wind generation than existed in the United States at the end of 2008. Expanding our wind turbine fleet from 2008’s 1.25% wind generation penetration to 5% would represent a total wind production of over 100 Gigawatts, enough to power over 25 million homes.

Although the market slowed in 2009, 2010 is expected to be a banner year for the wind industry, likely surpassing 2008 as the greatest growth year ever for wind projects. This massive growth is expected not only because of the stimulus money that’s now permeating the industry, but also because of the practicality and economic benefits wind power provides. It’s good news all around.