It was the late 1800s and there was a two-way war for monopolistic reign over the electricity market. Thomas Edison’s direct current (DC) against Nicola Tesla’s alternating current (AC) (yes, these inspired the classic rock heroes, ACDC). Edison lit New York with his direct current, but Westinghouse (who owned Tesla’s patents) won the opportunity to light the Chicago World’s fair of 1893. Locally, both were impressive feats of science that baffled spectators, but shortly thereafter there would be the ultimate challenge of scale: Using Niagara Falls to power Buffalo, NY.
It was well established that there would be an enormous project that would include power generation at Niagara Falls with transmission to Buffalo, NY. The world was not yet accustomed to the concept of electricity, nor its transmission. There was comfort in mechanical technologies and it was uncertain which would win out.
On the committee, seven of the 14 votes were in favor of electricity, while the others composed of water mains or steel cables on posts with pulleys that would span the 22-mile distance to Buffalo. Finally, the most likely alternate technology was in the form of compressed air as (ironically) recommended by Westinghouse, who was heavily invested in Tesla’s technology, but did not believe in its ability to handle the scale of such a project (we’re going to go ahead here and say that Westinghouse was the business mind, not the scientist), but Tesla knew better.
For a short time, they tried to bring Buffalo to the power. There a tunnel that was built to harness the great power of the river by locating mills and factories on-site, but due to large risks and an unfavorable IPO, it became increasingly clear that the energy needed to be transmitted over distance to Buffalo.
Over time, technology was improved and ultimately, Edison’s DC power could not compete with Tesla’s AC power in the fundamental issue of transmitting the electricity efficiently. Both forms of power, AC and DC, could be transmitted at high voltages, which allowed for greater efficiencies as the current can be increased while resistance remains constant, but the fundamental difference was in transformation. DC could not be transformed to a lower voltage that people could use in their homes and thus could not transmit its current over long distances without huge losses of power.
To review some of the proposed technologies:
- Water mains would have allowed them to bring the flow/hydraulic energy to be transformed near Buffalo, but this could be difficult, costly, and high-maintenance.
- Steel pulleys would likely require less maintenance than water mains (yet, still higher than electricity), but would decrease the efficiency to an even greater extent with an extra transformation. Finally, 22 miles would result in a lot of frictional inefficiencies and a long distance to protect.
- Efficiency of compressed air would be inversely proportional to its power as greater power would cause greater heat to dissipate and this would require a very effective system of sealants, which likely weren’t as effective in the late 1800s as those we have today. So they would have lost energy through lost heat and the loss of compressed air.
As it became evident that electricity may really be the most feasible proposal, AC and DC stepped in the ring. There were two proposed methods of transmitting DC power at high voltage and stepping it down to a lower voltage for residential and commercial use in Buffalo:
- They could use the DC over long distances to then power a motor in a separate building to produce a smaller voltage to transmit to commercial and residential buildings. This however, requires multiple conversions and, in the end, proved to be less efficient than AC due to losses.
- The other was for 5000-volt transmission to charge storage batteries in Buffalo for redistribution. Again, extra conversions will cause losses in power and 5000V is not high enough to render negligible the resistive heat loss.
In the end, Tesla’s alternating current won out because it could be transmitted at high voltages over long distances and subsequently stepped down to tolerable voltages when it reached buffalo without layers of inefficient transformations.
Today, the two work harmoniously to fulfill different roles. The AC power is often used to transmit over long distances, and to power your lights, but is often transformed to DC to charge your phone or run electric motors that require direct current.