Can farmers farm the sun?

India’s two biggest future challenges could be agriculture and energy. Agriculture is in crisis since grain production has stagnated for seven years. And if India’s GDP rises 40-60 times by 2050, as predicted by Goldman Sachs, energy consumption will rise at least 20 times, exacerbating the global energy crisis.

Farmers complain that no new, high-yielding grain varieties have been developed recently. Switching from grain to fruit and vegetables could improve farm incomes. Reliance, Bharti and other corporations are linking farmers to retail hypermarkets. The corporations provide farmers with inputs and know-how, and buy the produce at agreed prices. However, these initiatives cover only a few thousand acres. Even if this goes up to one million acres, that will be just 0.25% of India’s cultivated area.

The energy crisis suggests another way forward. When oil crosses $ 70/barrel, ethanol made from sugar cane is fully competitive with petrol. Bihar has ideal conditions for this crop. Cane yields far more income than grain.

An exciting new technology still being developed is cellulosic ethanol. This can convert not just cane juice but bagasse into ethanol. It can convert tall grasses into ethanol, and some giant grasses can be grown in areas submerged during the monsoon, providing a crop where none is possible today.

The US produces ethanol from maize. But this is an uneconomic process dependent on huge subsidies and import tariffs. Making ethanol from maize needs so much energy that the energy balance is reckoned at only 1.3. That is, the energy content of ethanol is only 1.3 times the energy needed to produce it. The energy balance is 8.3 for ethanol from cane in Brazil. It will, hopefully, be even higher for cellulosic ethanol.

But even this may be sub-optimal, say some experts. They point out that the photosynthesis crop use to convert solar energy into biomass is very inefficient: only a tiny fraction of the sunlight is converted to biomass. Even less can later be converted into ethanol.

If farmers really want to harness sunlight for energy, the best process is not ethanol but solar electricity. Farmers should cover their fields with solar-electric panels which directly covert sunlight into electricity. In effect, farmers will farm the sun.

Unlike growing crops, farming the sun needs no irrigation, fertilizers or pesticides. It needs no tractors, ploughs or harvesters. It will yield income in the worst droughts. It is environment-friendly.

What’s the catch? Well, despite technological advances, solar electricity is still two to three times as costly as the retail price of power. The solar-electric industry is booming the world over, but this is based on big subsidies, justified on the ground that solar energy is renewable and non-polluting.

Decades of research have improved the energy efficiency of silicon-based cells from 6% to 15%. Crystalline silicon is expensive, but its price is predicted to crash in two years. Meanwhile thin-film solar cells using other chemicals are being developed. They are less efficient but much cheaper. Another thin-film technology called CIGS promises to be both efficient and low-cost.

The Economist, the British magazine, suggests that solar electricity will be competitive with coal-based power in three to eight years. If that doesn’t happen, there is a case for diverting today’s farm subsidies for power, water and fertilizers to solar-electric generation. This will also qualify for carbon credits from the Kyoto Protocol.

The sun provides more energy in one hour than the world consumes in a year. But this is a very dilute form of energy that needs to be collected over a large area. The roofs of buildings are obvious sites. We also need to consider covering farmland.

Romantic pastoralists will howl against the diversion of fertile agricultural land. But solar electricity is best produced in hot, arid areas with the fewest cloudy days. These regions have the most poverty and lowest crop yields. Solar panels in Kutch and Western Rajasthan would displace very little farming. They could produce power for large parts of India during the day. Night power could be provided by conventional plants.

Some will worry about the loss of farm jobs if land is diverted to solar electricity. But ample rural power will generate higher-productivity jobs with higher wages than farming can provide. Agriculture today provides only 20% of GDP but employs 60% of the workforce. We must shift workers out of agriculture into other areas.

Farming the sun may be feasible only for a small percentage of Indian farmers. Yet this could substantially benefit the poorest areas.

Too futuristic? Maybe. But experts claim that solar electricity will become economic soon. We must start contingency planning now itself for what could be an energy revolution.

Deepak Puri’s company Moser Baer is spending $ 250 million to build the world’s biggest plant (200 MW capacity by 2009) for thin-film solar cells near Delhi. This is a courageous gamble: thin-film technology may not ultimately beat alternative technologies. But such initiatives deserve encouragement. Solar electricity can help meet India’s two major future challenges, in farming and energy. I suspect the future is solar.

What do you think?