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Coaxing Snow from Clouds by Emily Jones, Features Editor Idaho State Journal - February 27, 2005

Utility's cloud seeding aims to boost runoff, power generation

Idaho Power officials have heard the concerns about cloud seeding before.

They have heard that cloud seeding projects steal snow from other areas, a phenomenon they say is not proven.

Others have told them it's fooling with Mother Nature.

With emissions from smokestacks, vehicles and elsewhere traveling into the atmosphere, Mother Nature is far from on her own already, he said.

"Believe me, we fool with Mother Nature every day," Idaho Power Senior Meteorologist Gary Riley said.

For the past three years, Riley has led a cloud seeding pilot project for Idaho Power in the mountains of western Idaho. The project was designed to create more snow to send runoff into Hells Canyon Reservoir, one of Idaho Power's main sources of hydroelectricity.

The past few years of drought have been vexing for power production as well as for agriculture, Riley said.

According to the National Drought Monitor's weekly report, southeast Idaho remains in "extreme" to "exceptional" drought.

The most recent National Weather Service predictions, released Feb.17, show the entire state's drought situation is expected to persist or worsen through May.

In the Payette and Boise area, where Hells Canyon gets its water, streamflows are 60 to 80 percent of normal.

"It's been a dry year, and there's no relief in sight," Riley said.

Even in years when water isn't a big issue, Idaho Power plans to use cloud seeding to help increase the snowpack.

"This is not a knee-jerk reaction to the low-water conditions we're in right now," Riley said. "It is a carefully thought-out plan to help us understand and utilize programs to help us get through drought years now and in the future."

Idaho Power became interested in the cloud seeding business in the mid-1990s after customers suggested it. A pilot project began in 1996 and 1997, but was discontinued after natural snowpack reached well-above normal levels.

In 2003, Idaho Power reinstated its pilot project. With each cloud seeding, the company releases non-toxic tracer chemicals so they can track how much snow is a result of cloud seeding. Sample snow from the target area is melted and run through a spectrometer to see if it contains the chemical.

From February 2003 to April 2003, Riley said analysis showed a 16 percent increase in precipitation, amounting to about $1.7 million in additional electrical generation capacity. The extra snow created would create as much electricity as Shoshone Falls generates in a year, he said.

From November 2003 to April 21, 2004, analysis indicated a 5 percent increase in precipitation. So far this season, early results show a 10 percent increase.

Cloud seeding is not snow-making, but "snow augmentation," Riley said. Without a cloud, cloud seeding is worthless, he said. With this year's dry winter, there have been few chances to seed. Riley said he expects to improve precipitation by about 5 percent this year.

"If Mother Nature doesn't give us anything to work with, there's nothing we can do," Riley said.

Riley believes the evidence collected over three years is enough to show that cloud seeding is cost-effective in western Idaho. After this season, he hopes to have enough evidence to warrant running a full-scale project.

The Idaho Public Utilities Commission agrees that the project seems to be working. In December, it approved Idaho Power's application to include about $950,000 in cloud seeding costs when the company applies for a rate adjustment this spring, citing the first two years of data and agreeing that the utility will save money.

The IPUC will review the expenses, and customers will pay 90 percent of what is approved. The shareholders will bear the remaining 10 percent.

Idaho Power officials say they believe the initial cost will be outweighed by the increased power generation, eventually saving money for the customer. The cost will also go down, Riley said, after the company is finished studying, and no longer has to use a trace chemical. The tracing chemical and the cost of studying it are about $250,000 per year.

"It's a lot more cost-effective than building a new power plant," Riley said.

POCATELLO- Although its new to Idaho Power, cloud seeding has been a part of weather modification technology for several decades.

"It's not a dark science," said Roger Fuhrman, director of water resources.

Cloud seeding projects have been used by Pacific Gas and Electric in northern California for more than 50 years. In Bannock County, Three Rivers RC&D uses a cloud seeding project for agriculture.

It hasn't been without controversy, however. Many have worried that seeding clouds will "steal" moisture from other areas. In 1993, the Montana Legislature passed a law requiring an environmental study and a $10 million bond before cloud seeding within the state boundaries. The controversy began after some farmers worried that North Dakota cloud seeders were taking moisture that could be falling in eastern Montana. A bill that would reverse the law is currently before the Montana Legislature.

Idaho Power Senior Meteorologist Gary Riley said there is no evidence to support the idea that cloud seeding steals moisture from other areas.

Clouds are constantly receiving moisture from upper flows, National Weather Service Meteorologist Vern Preston said.

"It regenerates itself," he said.

Although cloud seeding can be used to improve snow, it can't create snow from nothing, Preston said.

Conditions must still be right for a storm, he said, and there is no guarantee of a storm, either for cloud-seeding target areas, or the regions surrounding them.

BOISE- Vadim Kulikov says it's no more exciting than driving a car in the winter, but many would beg to differ.

When there's the possibility of a storm coming, Kulikov and co-pilot MIke Spinosa steer their plane into clouds filled with what scientists call "super-cooled liquid" to make it snow in western Idaho's mountains. Often, when they return, their plane is covered with ice from the sometimes treacherous ride.

Some pilots enjoy flying commercial trips across the country; others like driving into fires. Idaho Power is looking for the latter, spokesman Dave Lopez says.

"When other people are putting their planes away, we're asking these people to go out," Idaho Power Director of Water Management Roger Fuhriman says. "We send them into the mountains of Idaho, and, if something goes wrong, their options are limited."

Part of Idaho Power's pilot cloud seeding program includes seeding from an aircraft manned by Kulikov and Spinosa, who work for Weather Modification Inc.

The small plane, a Beech King Air C90, is known for its performance in icy conditions. Attached to the bottom of the plane are two large metal canisters filled with silver iodide and a chemical tracer.

To be right for snow, temperatures in a cloud must be just right, about 23 degrees.

The silver iodide is dropped into the cloud, and it works to make the super-cooled liquid particles large enough to fall from the sky as snow.

"What we're doing is growing snow," Idaho Power Engineer Shaun Parkinson said.

The airborne cloud seeding is sometimes used alone, but it can also be used in conjunction with cloud seeding from the ground.

"They're complementary," said Idaho Power Senior Meteorologist Gary Riley

BOISE- The ground-based cloud seeding equipment used to send silver nitrate into the sky is accessible only by snowmobile in the winter, but with today's technology, Idaho Power Senior Meteorologist Gary Riley can seed Idaho clouds from the Bahamas if he chooses.

Idaho Power's 14 ground-based generators (seven with silver nitrate and seven with a tracing chemical), are operated remotely by computer.

Weather stations on each generator, along with information from weather balloons launched in Garden Valley, tell Riley and his colleagues when conditions are right for seeding.

The generator sites form an 80-mile horseshoe shape, aiming to hit a 938 square mile target area, all above 4,500 feet in elevation.

About 20 minutes before a storm is scheduled to hit, the generators are activated.

When the generators are activated, a solution of silver iodide and acetone is injected into a propane flame. The silver iodide quietly and invisibly floats to the sky. It takes about 20 minutes to see the snow fall, Riley said.

Air seeding and ground seeding complement each other, Riley said. When it's too cold to fly, the ground generators can still be effective, and when it's too warm on the ground, the planes can do the work.