The US Government Accountability Office (GAO) is questioning why Department of Energy (DOE) loan funds are not paying out as planned. The participation hurdle is high, and there's about $16.6 billion in green vehicle loan appropriations going unused, the GAO found.

The funds come from DOE's 2005 Loan Guarantee Program and its Advanced Technology Vehicles Manufacturing (ATVM) loan program from 2007. These programs were a directive from Congress, but now House and Senate lawmakers on the powerful appropriations committee are hearing about the programs stalling out. The GAO report also told legislators that the DOE hasn't "closed on a loan or loan guarantee or conditionally committed to do so under either program since September 2011."

The GAO had interviewed applicants for the loan programs to evaluate the DOE's performance and found that it the "costs of participating outweigh the benefits." Those costs include a "lengthy and burdensome" application and review process and lots of documents needed to apply. The failure of the solar energy company Solyndra was also mentioned as making participants skittish about working with DOE and the Obama administration. It's not just green car money that's sitting unused. There is $34.8 billion left in various renewable energy project loans, but here, at least, there are 13 "active" applications.

The DOE might be finished issuing funds through the programs automotive. While the funds don't have an expiration date, DOE says it will continue to receive applications and it doesn't plan to use the remainder of the appropriated funds.

Ford, Nissan, Tesla and Fisker did receive ATVM program funds. Tesla is doing well enough to pay the loan off early but Fisker had its funding cut short and is not in a good position to pay it back any time soon.