Something significant will happen to the world this year: More people will live in cities than in the countryside. We will need more food, more living room, more everything—and more energy for everything.

In the 1950s, Homi Bhabha, the father of India’s atomic programme, said nuclear energy would become so cheap that it would not be necessary to meter it. Obviously, that hasn’t happened. It never will.

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How does the world get its energy today? A quarter comes from coal, one- third from natural gas, and 35% from oil. Nuclear power provides 6%, trailing biomass at 10%; hydro provides a measly 2%.

Two days ago in Bangalore, I heard Dilip Ahuja point out that we are today using as energy sources almost everything we used 100 years ago. Ahuja, a professor at the National Institute for Advanced Studies, said that while we need transitions to clean energy, such transitions happen in decadal time scales, as in five to seven decades. Though billions live off the grid, the world does not face an energy crisis. Fossil fuels can still run the world for centuries.

Yet, it is clear that business cannot continue as usual. Of course we cannot continue to poison ourselves and continue converting earth into a giant greenhouse. But the big incentive to change the fuel mix will come from economics. We may uncover new sources and innovative ways to squeeze more fossil fuels out of earth, but it will become increasingly more expensive.

This is why the world’s traditional power producers are hedging their bets. This week, India’s century old Tata Power Co. Ltd, said it was partnering an Australian solar-power company to build India’s first low-cost, floating power plant. Does this sound esoteric?

It gets better.

Earlier this week, Daniel Nocera, an MIT chemistry professor and energy guru, told me how he had signed a deal with Ratan Tata to develop in 18 months a prototype of a technology that promises to extract power from dirty water. Nocera is trying to give life to an old scientific dream — to mimic photosynthesis, the way plants breathe, converting energy from the sun by splitting water into its component molecules.

This is a period of flux. Some technologies may work, many might fail. Local solutions will become important. For instance, Brazil’s great success with ethanol—the fuel now runs almost all vehicles in that country—from its sugar cane fields cannot be replicated in India. There isn’t enough space or water for thirsty sugar cane. An Indian solution that’s long been propounded has been fuel from the jatropha tree. But if India grows 10 million hectares of jatropha, making it the third largest crop after rice and wheat, it will still meet no more than 7% of national fuel needs.

What might work better are small, regional solutions for 500 million Indians off the grid. There are nearly 50 types of biomass in use across India, including rice husk, groundnut shells and coconut shells. Rice husk is the most commonly used fuel, and as bio-energy company Husk Power Systems has shown in Bihar, rice waste can power villages.

Laboratories are experimenting with many high-tech additives to the fuel mix. Rajan Patnaik, head of the Biofuels Research Group at Bangalore’s Du Pont Knowledge Centre, talks of the promise of bio-butanol as a more efficient alternative to ethanol, particularly to blend with petrol or diesel (one-fifth of all fuel must be blended by 2017, says India’s biofuels policy). Du Pont has a joint venture with BP (Petroleum) to extract a type of ethanol from agriculture residue. There are other technologies being incubated: diesel from algae, efforts to manipulate genes of yeast or certain bacteria to “grow" fuel.

G.S. Deshpande, the engineering head of Pune’s Thermax Ltd, is only half joking when he says the future is solar—after all, fossil fuel is solar energy converted millions of years ago. Thermax is working on a solar and biomass hybrid project, funded by the department of science and technology. It may not replace big oil, but such hybrids are important to cut oil demand.

Diversifying energy must be accompanied by greater efficiency. A study done for the Planning Commission by Bangalore’s Centre for Study in Sciences, Technology and Policy points out that with much of India’s infrastructure still to be built for its urbanising masses, new, efficient power plants must be built to the best global standards.

An MIT study shows how a house with sensors that automatically turned off power to unpeopled areas delivered a 43% saving (but then Americans are not known to be energy-efficient). In Bangalore, an Infosys group has shown how such efficiencies can be built into local grids. The Infosys campus in Bangalore now deploys this technology, which powers down vacant work areas. Bills are down 10%. The urban future may not be as dark as it appears.

Samar Halarnkar is editor-at-large,Hindustan Times. This is a fortnightlycolumn that explores the cuttingedge of science and technology.

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