First Solar (Nasdaq: FSLR) said construction permit issues might undo the October sale of the 230 MW Antelope Valley solar project in California to Exelon Corp. (NYSE: EXC) because the U.S. Department of Energy has not released the funds for the project.

In September, the DOE had finalized a $646 million loan guarantee to support financing for the Antelope project, but the funding was dependent on the project getting it’s necessary permits. However, First Solar said in a filing with the U.S. Securities and Exchange Commission that if the initial funding for the project did not come through within four months, itwould repurchase the project for $75 million, plus costs. Both parties agreed to extend the timeframe for initial funding of the loan to February 24.

First Solar sold Antelope Valley to Exelon for $75 million, and said it could buy the project back with existing cash and other resources. If First Solar were to reacquire the project, it would be available for sale to another party.