On New Year’s eve, a helpful federal solar incentive will turn into a pumpkin.

The American Recovery and Reinvestment Act of 2009 made it possible for businesses to receive a cash grant worth 30 percent of the cost of renewable energy projects. At the end of the year, the grant reverts to a 30-percent tax credit, which is in effect through 2016. And since cash is king, especially in slow-growth economy, the fast-approaching deadline has businesses scrambling to get their solar energy projects underway.

It also has agencies that oversee big commercial solar installation, like the California Energy Commission (CEC), scrambling to keep pace with a barrage of solar project approval applications. As a result, eight utility-scale solar energy projects have been given the green light in roughly three months.

In order to qualify for the federal renewable energy grant, projects must be in construction or developers must have spent a minimum of five percent of construction costs by the end of December. Most experts are doubtful we’ll see the federal grant option again in the future.

The end of the line for federal renewable energy grants doesn’t necessarily spell the end for incentives for residential solar energy systems. There’s still the 30-percent tax credit. And, depending on where you live, solar rebates, tax credits and other incentives may be available to help homeowners and small businesses install solar panels.