Honolulu-based Hoku Corp. won a partial victory from Idaho regulators Friday in its quest to reduce the high electric bills threatening the viability of a polysilicon plant it is building in Pocatello.

The Idaho Public Utilities Commission last week denied Idaho Power’s request to collect an additional $1.8 million cash deposit from Hoku. The PUC also ordered Idaho Power to renegotiate its contract with Hoku for future electric bills.

Idaho’s largest electric utility had threatened to cut off power to Hoku’s $390 million polysilicon plant because the clean-energy company was behind on its electricity payments. Idaho Power said Hoku’s arrearage included an unpaid November electric bill for $1.9 million due on Dec. 21 and the $1.8 million deposit that was due on Dec. 31.

Polysilicon is a key component in the construction of photovoltaic panels. Hoku and other polysilicon producers have suffered from falling polysilicon prices over the past year.

Cash-strapped Hoku paid its November electric bill Friday after receiving approval to borrow up to $10 million from a Chinese bank. Hoku also obtained relief when the Idaho PUC ruled that it did not have to pay the $1.8 million deposit, which was sought in addition to a $4 million deposit Hoku already paid to Idaho Power.

"We’re extremely pleased that the PUC found the additional deposit of $1.8 million to Idaho Power unnecessary and ordered the utility to renegotiate Hoku’s monthly billing arrangement, starting in January 2012," said Scott Paul, Hoku’s chief executive officer.

"This order is critical in assisting Hoku realize its goal of manufacturing clean-energy products and continuing to create high-quality jobs in the United States," Paul said. Hoku has estimated that the plant will create about 160 jobs.

In its order Friday the Idaho PUC also denied Hoku’s request to suspend its December electric bill, which is due Thursday. The PUC said that if the bill is not paid, Idaho Power would be allowed to cut off electrical service to Hoku on Jan. 26. Hoku officials said they will pay the bill by the due date.

Hoku’s dispute with Idaho Power stems from an agreement it signed last year that required Hoku to make monthly payments to Idaho Power beginning in April regardless of whether it was consuming any electricity. Because the polysilicon plant was behind schedule, Hoku did not need to draw any power until November. Paul estimates that, to date, the company has paid Idaho Power about $15 million for electricity Hoku did not use. That amount is on top of the roughly $18 million Hoku paid Idaho Power to build transmission lines and provide other electrical infrastructure for the plant.

The PUC ordered Idaho Power and Hoku to "enter into immediate negotiations" to amend the power contract. Regulators said the two sides are required to provide a progress report by Feb. 1.

"We look forward to engaging on a constructive dialogue with Idaho Power to modify the terms of the agreement," Paul said.