BOISE — Idaho's renewable energy landscape is strewn with failed projects, but more casualties may soon be added to the list after Idaho Power Co. demanded state regulators cancel the utility's contracts to buy electricity from two proposed dairy manure digesters.

Idaho Power says Boise-based Exergy Development Group's two biogas-to-power projects near Twin Falls have missed or will miss deadlines to deliver electricity to the state's biggest utility, according to filings with the Idaho Public Utilities Commission.

Exergy counters that circumstances beyond its control — in this case, pending rules governing small renewable projects still being hammered out by the IPUC — have scared off its financiers, making such developments impossible.

Among other things, Idaho Power is asking the Idaho Public Utilities Commission for permission to pursue Exergy for undisclosed damages for not delivering electricity when it said it would.

"We're just looking at enforcing the terms of the contract," Brad Bowlin, an Idaho Power spokesman, said last month.

Once one of Idaho's biggest renewable energy developers, Exergy has been beset by bad news for months.

The Boise-based company suspended $323 million in Idaho wind projects in August. It's also embroiled in federal lawsuits, one over wind turbines in Pennsylvania Exergy wanted but didn't pay for, and the other over control of a Minnesota wind farm. Last month, Exergy relinquished ownership claims to the Minnesota project.

Now, its proposed digesters — at the Double B Dairy in Murtaugh and Swager Farms, in Buhl — appear to be in jeopardy.