Photo: Eitan Iron

A THICKET of tangled wires brings electricity to shops at Crawford Market in Mumbai.

The squeals of children at play slice through the thrum of cars and powered rickshaws motoring by a high‑rise apartment complex in Khar, a neighborhood of narrow, tree-lined lanes in west central Mumbai, the city formerly known as Bombay. This pulsating island of 18.2 million, the most populous city in India, is the economic engine that is propelling the country into the ranks of the developed world.

The cacophony of traffic noises, construction clatter, and cawing crows filters into the spacious one-bedroom apartment I’m staying in, where the clamor from the street melds with the sounds of modern electrical conveniences: the humming refrigerator, the shushing ceiling fan, the burbling water heater, the droning air conditioner, and the howling espresso machine.

I crank up the volume on the cable-connected TV to hear the BBC anchor report the day’s headlines. Three new luxury condominium complexes are going up where a slum used to be. Many such developments are ringed by tarp-covered shacks and ramshackle low-rise concrete boxes of the sort that house half the city’s citizens, making Mumbai home to one of the world’s largest slum populations. In mid-2006, former slum dwellers in this particular neighborhood—many of whom provide the surrounding middle-class households with essential services such as garbage removal and delivery of newspapers, as well as bread, fruits, and vegetables—were moved into an unfinished apartment building, positioned cheek by jowl with the flashy new condos.

The recently relocated slum dwellers might not have glass in their window frames, but they have lights and televisions. They are by no means uniquely privileged among Mumbai’s poor, nor is the cost of power generally out of reach even for the less-well-off inhabitants of the city. At as little as 2 rupees (less than 5 U.S. cents) per kilowatt-hour, Mumbaikars are not shy about using electricity. At dusk, a few kilometers farther east and south in Dharavi, the largest slum in Asia, with about 1 million residents, cramped one-room apartments glow with electric light, and TVs flicker blue through open windows.

Readily available, affordable, and reliable power is the basis for any modern city. With it, you have the signature bright lights of Times Square in New York City and the psychedelic neon orgy of the Shibuya district in Tokyo. Without it, you get Lagos and a choking haze of diesel fumes spewed by thousands of generators, dirty and expensive substitutes for grid-­connected electricity. Visitors often compare Mumbai not with Lagos but with New York City. One big reason is that Mumbai enjoys dependable electricity and always has, ever since Mumbai-based Tata Power Co.’s first hydroelectric stations started pumping electricity to the city’s textile mills in 1914.

It seems like a cruel joke, then, that just as India is poised to become an economic superpower, the utilities in the country’s showcase city have launched their own public-service campaign urging Mumbaikars to conserve energy or face extensive planned outages this summer for the first time ever. A blackout that knocked out power in the northern half of the city this past February further illustrates Mumbai’s precarious situation.

“The load is rising a lot faster than anybody realizes,” says Gerry F. Grove-White, Tata’s executive director and chief operating officer. “I look out my flat and every tower crane I see, I see increased load,” he says over the loud rasp of his office air conditioner. “And the investment in generation has not kept pace. Last year we scraped by. This year the jury is out when summer comes.”

Everyone who has access to electricity in Mumbai—up to 95 percent of the population according to the utilities—has it 24 hours a day, every day of the year. “The reliability of power is so good in Mumbai that it is not an exaggeration to say that most of the people don’t keep any torches or even candles for emergencies,” says Dilip A. Sathe, general manager of Tata.

No one else in India is so fortunate. Last January, total peak demand for power in the country exceeded supply by 15 540 ­megawatts. Planned load shedding is common, especially in rural areas, although cities, including the megacities of Delhi and Kolkata, are not immune: utilities cut power to customers for hours at a time to balance load and generation capacities and in so doing keep the generators turning between 48.5 and 50 hertz, the frequency specification of the Indian electric system.