"Idaho Power, by submitting a flurry of legal complaints to the PUC, has made it all but impossible to secure financing for renewable projects, exacerbating the problem," Carkulis said. "These digesters are becoming collateral damage in this campaign against renewable energy in Idaho."
The PUC held contentious hearings over the summer, on issues including whether developers like Exergy or utilities like Idaho Power should own valuable environmental credits generated by renewable projects.
The three-member commission isn't likely to publish its new rules until mid-December.
Idaho Power disputes that Carkulis' financing woes and regulatory uncertainty constitute a so-called "force majeure" — an earthquake, for instance, or civil strife — that should allow Exergy out of its contracts.
"The claimed events do not excuse (Exergy) from meeting the operational requirements," utility lawyers wrote.
At least initially, it will be up to the regulators to decide which side is right, though the dispute could end up in state court.
"The commission will determine whether that really is a valid reason for accepting a delay in the contract," commission spokesman Gene Fadness said of Exergy's claims.