It starts with a snowflake, and powers the Northwest

E-mail this article Print this article Other links GOP urges Locke to play it tough with California Energy woes affect waste-water utility; sewer bills, too, could increase Calif. cities with stable electricity source woo business Davis signs plan for Calif. to sell power to residents

MOUNT BAKER NATIONAL RECREATION AREA - Scott Pattee stood 3,400 feet above sea level in a Whatcom County mountain meadow, Ground Zero for the Northwest's snow drought. He jammed 7-1/2 feet of polished aluminum tubing into the snow and pulled out a 50-inch explanation of the West's power crunch.

A portable scale showed the tube contained the equivalent of 18 inches of water. That's half of what usually falls by this time of year, and about the lowest in the region.

"Right now we should be accumulating a lot of snow," said Pattee, a water-supply specialist for the U.S. Department of Agriculture's snow-survey program, as flakes straggled from the sky.

To run a 100-watt light bulb for a second, you need about 100 million snowflakes. And that is only the beginning of the technologically marvelous, yet surprisingly vulnerable, process that runs millions of lights, computers and stereos every day.

Electricity producers have the luxury of operating in a captive market: Everyone needs what they are selling. Payment is, for the most part, guaranteed.

The downside is that electricity fundamentally depends on nature, whether it comes from snow, the sun, coal or natural gas.

Then, once it is produced, it moves at the speed of light, making it a real-time commodity that must be sold instantaneously. And tracking its flow is largely a matter of educated guesswork.

"Essentially, power follows the laws of physics," said Lloyd Reed, director of Puget Sound Energy's power-supply operations. The Bellevue-based utility provides electricity to 920,000 customers in the region.

"It follows the path of least resistance. When a Puget customer turns on a TV, it may come from many different sources. It may not even come from Puget. It may come from Colorado, California, Canada."

The not-so-simple route of an electron, in this case an electron powered by a melted snowflake run through the Puget Sound Energy system, shows just how complicated the course can be.

Snow, water and gravity

Melting a snowflake and sending it streamward seem straightforward enough - after all, water flows downhill. But calculating how much snowmelt will come, and when, requires the small army of snow watchers in the federal Cooperative Snow Survey Program.

Using a computerized data-collection network and forecast system, the program juggles the soil's moisture content, ground water, precipitation patterns and storms to estimate how much water might be available for hydropower in the coming weeks and months.

Bob Barnes, a hydrologist for Puget Sound Energy, also factors in measurements from nine snow stations - vertical markers sticking up in the snow and photographed from the air. It's a squirrelly business, said Barnes. There are no reliable models for projecting weather and stream flows three to six months ahead, but the snow is vital to power production."The snow is essentially our third reservoir," Barnes said.

The other two reservoirs are Baker Lake, which empties through the Upper Baker River Hydroelectric Project. The water then flows to the Lake Shannon reservoir, the main water supply for the Lower Baker River Hydroelectric Project.

When it was built in the mid-1920s, Lower Baker was the highest hydroelectric dam in the world. Far larger and more powerful dams have been built since - Grand Coulee Dam is more than 30 times more powerful - but the Lower Baker dam is cheap to run, and it's paid for.

More modern turbines have made modest gains in efficiency, but at their core they all produce power through a simple physical reality: gravity.

Water drops 250 feet into the turbine at Lower Baker, increasing in velocity as it gets squeezed from a 22-foot-wide pipe into a 16-foot-wide penstock. At that point, as much as 4,000 cubic feet of water - enough to fill two backyard swimming pools - are moving by each second. The turbine then spins a 3-foot-thick steel shaft at about three turns a second. It's slow enough to track with the eye and would seem downright torpid if it weren't for all the work it's doing - it has up to six times the horsepower of the Indianapolis 500's 33-car field.

The shaft runs up to a massive magnetic rotor - the two pieces weigh a total of 200 tons. At this point, a more elegant physical reality comes into play: When a conductor such as copper is moved through a magnetic field, its electrons begin to flow.

The rotor spins inside a locomotive-loud generator housing of coils, or wound wire, pushing that current into the hinterlands.

"Those coils are what are hooked to your house," said Leonard Simpson, the dam's resident operator.

At full capacity, the Lower Baker plant can power about 70,000 homes. But first its power has to get to Sedro-Woolley in Skagit County, the closest onramp to the Western power grid.

To move efficiently over long distances, power has to be prepped.

Power lost

One in every 20 watts sent across the vast reaches of the West gets lost in the form of heat and, to a far lesser extent, radio waves and even sound. Using a top-quality conductor such as silver can cut the loss, but transmission lines made of stranded aluminum and steel cost far less, justifying the modest decrease in power.

Engineers minimize the loss by increasing voltage (the pressure put on the electrons) and lowering the current or amperage (the movement of electrons). And because power is the product of voltage and current, engineers can transmit the same amount of energy at the lower, more efficient amperage.

At Lower Baker, this is done with transformers that step up the voltage from 13,800 volts to 115,000 - the voltage for most of Puget Sound Energy's transmission system.

The process will later be reversed at substations and, finally, the pole-top transformers on residential streets.

Now the power is ready to go to Sedro-Woolley, where it hits an intertie - one of a system of connections at which electricity from different utilities can merge onto the Western power grid that stretches from British Columbia to Mexico. Now Lower Baker's power is part of a pulsing network capable of carrying as much as 140,000 megawatts from about 900 plants.

Power planned

But the power cannot simply be dropped onto the grid. It needs a place to go - immediately - and producers must delicately match supply with demand. They have to know customers are going to be there to take electrons off the grid.

"It's very rare that every hour you're exactly matched, and then you go home for the day," said Reed, Puget Sound Energy's power-supply director. Much of the utility's power is planned out a day or two earlier, when Reed's group weighs the company's generation ability against what customers might need. The utility buys two-thirds of its power, with traders buying power for the next month, the next day or, in Max Staple's case, the next hour.

Staple is a real-time energy trader. He tries to buy low, which on one recent day meant $275 to $290 a megawatt hour, and sell high, which on that same day meant $350 a megawatt hour. He tries to maintain a poker voice on the phone.

In his spare time, he day-trades from home.

His job is twofold: to make sure there's enough power, and to get it at the best price.

Staple's trading pit is the 14th floor of One Bellevue Center. On a clear day, he gets a fantastic view east to the rocky snowpack on the Cascades. Most of the time, he looks at eight computer screens tracking power and prices.

He's been doing this for 20 years for various utilities. This year, with spot prices fluctuating wildly and spot supplies critical during California's rolling blackouts, "there are times I can't answer the phone fast enough," he said.

On a slow day, he'll trade 100 megawatts in an hour. Other days, he can handle as much as 1,500 megawatts in an hour. That's more than 20 times the output of Lower Baker, or a quintillion snowflakes.

Power moved

The physical movement of high-voltage power across the Puget Sound Energy system falls to people working out of a vast basement control room in Redmond. For security reasons, only employees with coded key cards can enter.

"If you want to shut down the Northwest, this is a good place to start," said Dennis Christopherson, a senior power dispatcher.

Twenty-four hours a day, seven days a week, at least two people like Christopherson sit watching a massive curved wall on which Puget Sound Energy's north-south grid is positioned on its side. To the left is Portal Way, a substation one mile south of the Canadian border; to the right is Centralia, Lewis County.

Green, black and orange lines representing up to 500,000-volt lines, crisscross the wall. Coursing through them are 2,800 megawatts - or the equivalent of 40 Lower Baker dams.

It bears repeating: The power coursing through this system has to have a place to go. By the same token, if someone needs power, it has to be there at that moment.

"You make it in real time," said Jerry Rust, director of the North west Power Pool, which coordinates power operations across the region.

"And then you have to transport it in real time and then you have to use it in real time."

It's a little after 2 on a weekday afternoon, and the slow midday hours are giving way to the peak demand period, 5 to 9 p.m. Customers are turning lights on and off. Elevators are going up and down.

Predictable pattern

"In the next hour or so, it's going to start picking up gradually," Christopherson said.

A squiggly line on a piece of rolling graph paper charts megawatts above or below supply. Christopherson wants the needle to track at zero, but it can go up or down by as much 50 megawatts.

The automatic fix kicks in.

A one-megawatt change or "error" sends a signal through an automatic generation-control system that adjusts the amount of power being produced. On this day, extra power comes from Rocky Reach Dam, whose power Puget Sound Energy buys from the Chelan County Public Utility District.

"People are getting off work now," Christopherson said. "Kids are getting home."