Where It Started — Power System Interconnections
The Kilovar — Infrastructure Series
Hello readers, a change of direction. We’re going to talk history in this series—jump in the way-back machine and take a look at where this wonderful machine that drives our modern world, the electric power interconnection, began.
Author’s note: always take claims of being “first” with a grain of salt, because someone will always find a way to argue your facts. What I include here are the earliest documented cases I’ve found. If you have some local history that belongs in this story, please add it to the comments.
Before Interconnections
The War of the Currents
Anyone familiar with the early history of electric power knows about the battle of the currents between George Westinghouse and Thomas Edison. Edison staged a massive campaign against the adoption of alternating current, ultimately at the sacrifice of his own personal reputation. Even while that war raged, Edison General Electric was quietly making the change behind Edison’s back. By that point, Edison was only a token shareholder. That’s another story, and there are many books and even a few movies on the subject.
One thing should be understood from the outset: even in the early DC days, generators were run in parallel. Parallel equipment operation was baked into the cake from the very foundation of the industry. What didn’t exist yet was interconnection—tying together separate systems, owned by separate entities, serving separate loads, into a coordinated whole. That’s a fundamentally different problem.
The Firsts
The Niagara Myth
George Westinghouse was a master promoter and played the press like an instrument. He made bold statements about his Niagara project to make it commercially viable, and many of those claims are still repeated today as fact. In that same cloud of promotion, Nikola Tesla has been associated with many inventions that were not his. Let’s set a few things straight.
Tesla’s biggest genuine success was inventing a self-starting AC motor. Up to that point, DC had a decisive advantage: DC motors started on their own, while AC motors needed assistance to begin rotation. Tesla’s induction motor solved that problem. It was huge.
But Tesla’s system was two-phase, not three—two completely separate windings ninety degrees out of phase, requiring four wires. The original generators installed at Niagara were two-phase machines with the stationary stator load windings in the center and the field windings rotating outside the stator, producing 25 Hz output. Tesla did not invent a workable transformer. And Niagara served local load only when it first came online.
The famous Niagara-to-Buffalo transmission line had to wait for the development of the Scott-T transformer connection that converts two-phase to three-phase. Niagara came online serving local load on August 26, 1895. Transmission to Buffalo didn’t begin until November 16, 1896. The plant started with 11 MW of capacity across three units.
Before Niagara
Several milestones were reached years before Niagara’s claimed firsts. This is not an exhaustive list, but it gives a sense of how quickly the technology was moving in the early 1890s—and how much of that movement happened in the American West.
Willamette Falls Station (1890) — Six 80 kW, 4 kV, 125 Hz units sending power over a single-phase line to Portland. Details are sketchy, but the installation was operating before Niagara broke ground.
Lauffen to Frankfurt (1891) — Built for the 1891 International Electro-Technical Exhibition in Frankfurt, Germany, this installation moved 180 kW at 40 Hz over a 109-mile, 20 kV transmission line from a hydro plant at Lauffen to the exhibition. It was a demonstration, not a permanent commercial installation, but it proved the concept of long-distance AC transmission to a European audience.
Ames Hydroelectric Plant (1891) — Near Telluride, Colorado. A 75 kW, 133 Hz plant with 3 kV single-phase transmission to a stamp mill. Small, remote, purpose-built for mining—but it worked.
The Bodie Single-Phase Transmission (1893) — In Bodie, California, the Standard Consolidated Mining Company completed a thirteen-mile, 3 kV single-phase AC line between a 125 Hz hydro plant and a single-phase motor. The motor drove a shaft-and-belt power distribution system typical of the time.
Redlands Power Plant (1893) — Two 250 kW, 50 Hz units in parallel at Mill Creek Hydro, feeding a seven-mile, 2,400-volt three-phase line to Redlands, California. Union Ice was the primary customer.
Folsom Powerhouse (1895) — This one matters for the rest of the story. Four GE 750 kW rotating-armature, stationary-field generators—likely a converted DC design—producing 800-volt, 60 Hz output. Three megawatts in total. Connected via dry-type air-blast transformers to an 11 kV transmission line running 22 miles to Station A in Sacramento. Sacramento became one of the first “electric cities”—streetcars, street lighting, commercial and residential power all served from a single hydro plant. Online July 13, 1895, six weeks before Niagara. (Author’s disclosure: I served as a volunteer docent at the Historic Folsom Powerhouse from 1990 to 1996.)
The First Interconnection
How It Happened
All of these early installations shared a common characteristic: they were isolated systems. One plant, one load, one owner. They proved that hydroelectric generation worked, that AC transmission worked, that you could move power over meaningful distances. But they were islands.
The step from isolated plant to interconnected system didn’t come from grand engineering vision. It came from desperation.
Folsom’s Problem
The Sacramento Electric, Gas and Railway Company—the Livermore family’s consolidation from 1896—was having a difficult time meeting Sacramento’s growing load. The American River was unreliable. Drought reduced Folsom’s output to a fraction of its capacity, and power transmission to Sacramento was being interrupted. The company was scrambling.
They took several emergency measures. They built a steam plant in Sacramento as a backup. They constructed a smaller tailrace powerhouse below the main plant to squeeze another 750 kW out of the same water by exploiting the 25-foot elevation difference at the mouth of the tailrace. They even moved Unit 4 down to the tailrace powerhouse as a stopgap. None of them were enough.
Sacramento’s load kept growing. The American River kept disappointing. The Livermore’s needed more power, and they needed it from a source that wouldn’t dry up when their river did.
Colgate—Built for Sacramento
Meanwhile, sixty miles to the northeast, two men were moving fast.
John Martin and Eugene de Sabla had already built the Rome power station on the South Yuba River near Nevada City in 1896, serving the mines of Grass Valley and Nevada City. In the spring of 1898, they built a 1,220-horsepower plant on the middle fork of the Yuba River to serve Marysville—and completed the entire installation in four months and five days.
They were fast. And they had ambition.
Sacramento Electric, Gas and Railway Company’s woes led to negotiations, and a contract was struck. The Yuba Electric Power Company was formed on January 30, 1899, to build the Colgate Powerhouse near Dobbins, California. The plant was named for its financier, Romulus Riggs Colgate, a New York soap fortune heir. Stanley Electric Manufacturing Company of Pittsfield, Massachusetts, supplied the generators.
In what would be an impressive feat even today, Martin and de Sabla built a three-unit, 2,700 kW power plant and a 61-mile transmission line to Station A in Sacramento—the same Station A that Folsom already fed. Construction photography began in July 1899. The plant came online September 4, 1899, just four days past the agreed-upon deadline.
In the fall of 1899, three generating sources were operating in parallel: Colgate hydro, Folsom hydro, and the Livermore’s’ Sacramento steam plant. Colgate handled speed and voltage regulation for the entire system. A 1912 article in the Journal of Electricity, Power and Gas documents the arrangement: “In the fall of 1899 energy was supplied to the system of the Sacramento company, the steam plant of the latter, the hydroelectric station at Folsom and the Colgate station being operated in parallel.”
What This Meant
This was not two generators running in parallel inside the same plant. This was two separate companies—the Livermore’s’ Sacramento Electric, Gas and Railway Company and Martin and de Sabla’s Yuba Electric Power Company—with separate generating stations fed by separate rivers, tied together at a common delivery point, operating in coordinated parallel. Colgate was designated as the frequency leader.
That required a host of things that wouldn’t become formalized for decades: operating agreements, frequency control responsibility, shared load dispatch, coordinated planning. A system operator at Colgate was holding frequency for generators he couldn’t see, owned by a company he didn’t work for, fed by a river he couldn’t control. Every problem that NERC would eventually write standards about was already present in embryonic form on the Yuba River in 1899.
The tie line operated first at 22 kV, then was raised to 40 kV, and finally to 60 kV as the system grew.
The Race That Made It Possible
Here’s where the story gets interesting.
Colgate was built to serve Sacramento. That was the contract, and that was the plan. But Colgate wasn’t the only hydroelectric project under construction in the Sierra foothills.
Prince André Poniatowski—a genuine Polish-French prince, descended from royalty—had first visited California in 1892 and conceived of harnessing the Mokelumne River for hydroelectric power after seeing Niagara Falls. He and his partners, including banker William Henry Crocker, incorporated the Standard Electric Company of California on November 27, 1897. Their precursor plant, the Blue Lakes Powerhouse, came online in October 1897, serving mines in Amador and Calaveras Counties.
Poniatowski’s big project was the Electra Powerhouse on the Mokelumne River. It would be a 10,000 kW plant with transmission to the San Francisco Bay Area—a distance that no one had attempted commercially. Stanley Electric proposed running the line at 50,000 volts over more than 100 miles. All three major electrical manufacturers—General Electric, Westinghouse, and Stanley—had told Poniatowski that no insulator existed that could handle 40,000 volts. He pressed ahead anyway.
But Electra was slow. Construction planning didn’t begin until 1899. The bunkhouse didn’t move to White’s Bar until November 1899. Water didn’t reach the main canal until February 1902. Electra’s five generators didn’t come online until May 6, 1902, with power reaching San Francisco in November.
Poniatowski had the earlier vision by seven years. He lost the race by three.
After Colgate was running and the Sacramento contract was fulfilled, the Oakland Transit Company came looking for cheaper power to operate its 126 miles of street railway in Oakland, Berkeley, and Alameda. Martin and de Sabla saw the opportunity. They organized the Bay Counties Power Company on June 4, 1900, consolidating their holdings.
Colgate power was first delivered in Oakland on April 27, 1901. The initial voltage was 40,000 volts, raised in 1903 to the 60,000 volts for which the line had been designed. Through a tie line to the substation of Poniatowski’s Standard Electric Company—which had not yet completed its Electra plant—power was supplied to Standard for delivery under contract to the Oakland Gas, Light and Heat Company. Standard also took Bay Counties power for delivery to San Jose, a transmission distance of 184 miles from the generators at Colgate Powerhouse.
The competitor whose plant wasn’t finished was buying power from the company that beat him to the Bay Area—and reselling it under his own contracts.
Within a few more years, the whole web—Bay Counties, Standard Electric, Valley Counties, and the rest—would be consolidated into a single entity: Pacific Gas and Electric Company, incorporated in October 1905.
The Grid Wasn’t Planned
The lesson of Colgate-Folsom is one that every system operator recognizes: the grid wasn’t designed from the top down. It grew from the bottom up, driven by necessity, competition, and opportunity.
Drought on the American River forced the Livermores to find supplemental power. A contract to serve Sacramento put Martin and de Sabla’s transmission line into the same station that Folsom already fed. The Oakland Transit Company’s appetite for cheap power extended the network to the Bay. The competitive pressure of Poniatowski’s Electra project created the market dynamics that pulled it all together. Each step was a response to an immediate need, not a master plan.
But the result was a master plan’s equal: an interconnected system spanning hundreds of miles, with multiple generating sources, multiple load centers, coordinated frequency control, and the organizational infrastructure to operate it. The birth of the grid in miniature.
Somebody at Colgate took responsibility for holding frequency for a system that included another company’s generators. From an operator’s perspective, that’s Day One.
Coming Up
In this piece we talked about the history—how the first interconnection happened and why. Next, we’ll look at what all these changes meant for the technology that quickly developed to make it work: synchronizing equipment, protective relaying, frequency regulation, and the operating practices that had to be invented from scratch because no one had ever run a grid before.
You have a story about your utility’s early history? Please share it. I look forward to your comments.
Sources
Charles M. Coleman, P.G. and E. of California: The Centennial Story of Pacific Gas and Electric Company, 1852–1952 (McGraw-Hill, 1952).
Archie Rice, “The Great Power Plant at Electra,” PG&E Magazine, Vol. II, No. 4, September 1910.
“World’s Largest Transmission System: Pacific Gas & Electric Company,” Journal of Electricity, Power and Gas, June 1, 1912.
California State Parks, Folsom Powerhouse State Historic Park historical documentation
What has always amazed me was how explosive the growth was. We are talking about time when things not on a rail car still moved by livestock propelled wagons over unpaved roads. That's not just the West, brick and cobblestone streets were strictly a urban thing. Lifting was done with block and tackle, no cranes.
The speed with which the industry grew speaks to the unfilled need that existed that small steam engines couldn't fill.
Very interesting that early demand was driven by the mining industry, and residential application was a secondary market that was probably an afterthought. Also funny how even the first systems were grappling with unreliable energy sources - rivers drying up. You'd think 100 years later we would know better than to keep pushing for these intermittent energy systems. Both items point to what were seeing today with data centers reviving nuclear interest in the US.