Utilities tend to be stodgy, conservative beasts. Left to themselves, they're unlikely to abandon the hulking coal-fired power plants that generate about 40 percent of Americans' electricity, because they provide cheap and abundant power and utilities are guaranteed to profit from its sale. So-called "investor-owned utilities" like Idaho Power are publicly sanctioned monopolies granted exclusive access to a city or region's customers so long as they provide affordable, reliable power. They profit by building new power plants and transmission lines, billing customers for construction and raising rates enough to reap a "reasonable rate of return." Public commissions oversee utilities, but once they have approved a new power plant and attendant rate hikes, utilities have little incentive to forsake it and its profits.

But what serves utilities' bottom line doesn't always serve the public's energy goals. That was true when PURPA was passed in 1978 to address soaring electricity prices by promoting clean energy and diversifying the country's energy mix. And it's true now, with the impacts of carbon a growing concern.

Political pressure can make utilities change, but seldom without a fight. In the early to mid-2000s, consumers and legislators began demanding that utilities lower emissions by generating clean electricity. Colorado's biggest utility, Xcel Energy, and small rural power providers successfully lobbied against renewable energy standards at the state Legislature. In 2004, Xcel bankrolled the campaign against an RPS ballot measure, saying renewable energy was too expensive and unreliable; voters disagreed, approving the renewable standard by a 7-point margin. PNM, New Mexico's major utility, also fought the state's initial renewable mandate. In the most liberal Western states, utilities didn't oppose the mandates outright. Still, they had reservations. As the amount of wind energy grew, Pacific Northwest utilities worried that a sudden drop -- or escalation -- in power would make the grid collapse.

Those fears were soon put to the test. Renewable portfolio standards -- plus carbon emissions limits for new plants in Oregon and Washington -- were historic shifts: For the first time, utilities had to consider climate change when building new power plants. No longer could they just exploit coal, the cheapest resource. Suddenly, gusty hilltops around the Northwest's Columbia Gorge were sprouting hundreds of turbines. Wind power did challenge grid operators, who must ensure that the amount of electricity being fed to power lines is equal to the amount being consumed. Coal, natural gas, nuclear and hydroelectric power plants make this task relatively simple by putting out consistent streams of energy. Wind does the opposite; its gusts can fluctuate wildly within 15-minute windows. Grid managers could no longer just tweak the output of individual plants to match demand. A certain amount of energy would have to be kept in reserve to be used in a pinch to prevent blackouts. Stabilizing wind also increased operating costs because some generators were kept on, just in case, even if power wasn't sold. Still, renewable energy standards offered opportunity. Big utilities acquired or built wind farms and secured rate hikes to cover the cost.

What resulted was widespread development of the Northwest's second great renewable resource. Thanks to large hydroelectric dams, which generate about 60 percent of the region's power and have predictable fluctuations, grid operators eventually married wind to water. In 2000, Washington, Oregon, Idaho and Montana hosted about 50 megawatts of wind-power capacity. Today, that figure is 8,500 megawatts, and the Northwest boasts one of the country's faintest carbon footprints.

Not once have the lights blinked out because the breeze faltered. Monthly electric bills are higher, but wind is only one reason; over the past six years, utilities have also invested heavily in updating infrastructure. And they still enjoy comfortable profit margins. In other words, fears of a collapsed grid and exorbitant costs proved unmerited. None of this, however, seems to matter to the wind debate in Idaho.