BOISE -- The Idaho Public Utilities Commission heard oral arguments Tuesday in a case that will play a big role in future development of wind power in the Gem State.

A complaint filed by Cassia Gulch Wind Park and Cassia Wind Farm alleges an Idaho Power requirement that small-power producers pay for nearly $60 million in transmission upgrades will stifle the economic development of a number of wind projects and delay development of renewable energy in Idaho.

"If we're saddled with a $50 to $60 million burden, there's no way I could entertain any investors to take on that risk," said Jared Grover, the developer of the Cassia wind projects near Hagerman, in an interview with CBS 2 News.

Grover is asking the Idaho PUC to determine that costs to upgrade be paid by all Idaho Power ratepayers, not just small-power producers.

The commission's decision could come next month. The PUC could rule in favor of the utility or the developers -- or determine a different connection cost formula altogether.

Grover agrees developers should pay for new feeder lines and substations to interconnect with Idaho Power's grid, but says the developers should not have to finance upgrades to the "backbone" of Idaho Power's transmission system.

"Basically, we're trying to separate out a driveway we're responsible for, and then a highway we think they're responsible for," Grover told CBS 2 News.

Idaho Power says the upgrade costs are justified because the additional energy from wind projects would overload the company's system. Idaho Power told wind farmers that they could pay for the upgrades up front and that Idaho Power would repay them over time.

Utilities are required by a 1978 law to purchase energy from qualifying small producers that generate power from sources other than fossil fuels although Idaho Power questions whether or not wind power can produce on demand.

"Can you turn on your light switch and get power from wind all the time? The answer is no, because the wind doesn't blow all the time," said Idaho Power spokesman Dennis Lopez. "But the company isn't opposed to wind power, we're just looking for a variety of energy resources to solve our customers energy needs."

According to the PUC, Grover is asking for expedited treatment because turbine costs are increasing rapidly.