Power Flows Long-Distance

Willamette Falls provided the power for the first long-distance electric-transmission line.

We pretty much take electrical power for granted today, but that hasn't always been the case…

By Alexis Madrigal

1889: The first long-distance transmission of electricity takes place, linking a powerhouse at Willamette Falls to a string of lights in Portland, Oregon, 14 miles to the west.

The power lines stretching from the hydroelectric generator to 55 streetlights at 4th and Main heralded the arrival of a major innovation in energy technology. The original design used continuous (or direct) current, not the alternating-current system that eventually became the standard way of transmitting power.

Before the Portland line, it was not clear how or even if electrical power could be sent long distances. After the Civil War, stationary steam engines began to flood into American cities, but the power they produced was local.

The era was epitomized by the great Corliss engine that dominated the Machinery Hall of the Centennial Exhibition, a celebration of American power held in Philadelphia during 1876. The huge 1,500-horsepower machines were connected to 5 miles of shafting that drove hundreds of machines.

“One reverences the noiseless handiwork of Corliss, which, with a slight strain of its muscles, contributes life and motion to all the vast machinery of the hall,” one literary journalist wrote. “The consentanous bones and tendons of the hundred-handed Briareus of New England’s mechanical genius leap at once into action, and proclaim, with voice vehement and not unmelodious, the victory of American inventive power.”

Power, the ability to do work, was fundamentally local. This fact shaped the way cities were built and the way people lived. People and coal had to live side by side, because you needed workers and steam engines in close proximity. Cities got filthy, the air clogged with soot. Pittsburgh, among other cities like Chicago and London, was renowned for its horrible pollution.

“If a sheet of white paper lie upon your desk for half an hour, you may write on it with your finger’s end through the thin stratum of coal dust that has settled upon it during that interval,” Peregrine Prolix, a wry, pseudonymous traveler from the South observed. “[Pittsburgh's] manufacturing powers and propensities have been so often described and lauded that we shall say nothing about them except that they fill the people’s pockets with cash and their toiling town with noise and dust and smoke.”

At first, when Thomas Edison and company began experimenting with electricity in coal-powered stations, they figured the system would look much like the steam-powered energy system did: Lots of small stations would be scattered across cities, burning coal to make electricity for customers in their immediate neighborhood.

But as engineers continued to tinker with electrical wiring, they began to see the possibility for electrical transmission. The powerhouse could be one place and the need for power in another. Cleaner, hydroelectric power sources could be tapped.

That is not to say that power transmission was not already possible when the Portland line went in. Indeed it was a great problem of the day to get power in larger amounts and farther distances (think of it as power bandwidth). Belts and shafts could transmit power a short distance with reasonable losses. Compressed air — pushed through tubes — was employed on a city scale in places like Paris and Vienna, but there was no solution for transmitting power tens or even hundreds of miles.

Even among electrical-transmission advocates, there were some people who favored continuous current, others who liked alternating current. Numerous details remained to be sorted out when the Portland line went in, but it proved that it could be done, albeit with losses of about 25 percent.

Major advances came quickly in the next few years. A German team built a 100-mile alternating current, high-voltage, three-phase transmission line from a hydroelectric generator to Frankfurt in the summer of 1891. It went many times farther than the Portland line, while maintaining the same efficiency of about 75 percent.

That convinced the hydroelectric developers of Niagara Falls to use alternating-current transmission to send their 200,000 horsepower all the way to Buffalo, New York, 22 miles away. When that plant went online in 1895, electrical transmission truly arrived. The company, in retrospect with deserved swagger, called the feat “the great step in the transition from mechanical power in industry to electrical power everywhere.”

The great centralization of the American power system had begun. Power plants would get larger and larger transmitting power farther and farther.

The trend would continue unabated for the next 80 years, until the energy rethink of the 1970s. The national electric grid now extends 157,000 miles across the country, mostly in three large networks: the Eastern, Western, and Texas interconnections.

Read More http://www.wired.com/thisdayintech/2010/06/0603long-distance-power-line#ixzz0pnZrUcgY