The electric supply industry (ESI) formally started when Thomas Edison established two thermal power plants around 1882, first in London and then in New York. Early plants, including those of Edison’s, were designed to produce and supply only low-voltage direct current (DC) power to consumers. These plants were located closer to consumers to serve them directly and were isolated from each other.

Power in electric circuits is the product of current and voltage. Any increase or decrease in current or voltage results in a proportionate decrease or increase in the other. Losses in the system, however, are not linear. Doubling the current leads to quadrupling of losses, and reducing the current by half reduces these to a quarter.

In the DC systems, current runs continually in one direction, like in batteries and fuel cells (Figure 1). These systems, however, had one serious constraint: once designed and deployed, the voltage in these systems was difficult to change.

Whether the above constraint drove them is hard to tell, but somewhat concurrently with Edison’s inception of his DC system, another group, led by George Westinghouse, introduced alternating current (AC) and successfully demonstrated, using transformers, the ability to raise or lower voltage as per the need.

The two groups quickly got entangled in a fierce battle during the first decade of the nascent ESI, which came to be known as “The War of the Currents”. Edison’s group fought tooth and nail against the other group, often resorting to below-the-belt tactics, but two events turned the battle in favour of the AC system.

The first was the Chicago World’s Fair that took place in 1893, at the height of the War of the Currents. General Electric of Edison bid to electrify the fair for half a million dollars, but lost to Westinghouse, which bid to do it for only 70% of that of Edison, using the AC system.

The second, and decisive, blow came when the Niagara Falls Power Company........

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