The Bali meet is focusing world attention on climate change. The question arises whether India, instead of cutting down on emissions, can develop ‘carbon-free’ technologies to achieve desired economic growth.The Planning Commission estimates India’s total commercial energy supply at about 4000 billion kwh. This is estimated to grow to 20,000 billion kwh by 2030. How India achieves this steep growth is in itself a challenge. It is compounded by the requirement that a ‘reasonable’ fraction of this energy be from carbon-free sources. What is reasonable? Many new carbon-free technologies are still to become feasible for large-scale implementation and coal, oil and gas at present supply 97 per cent of India’s commercial energy. It is, therefore, nearly impossible to make a major switch from conventional resources. One option would be to plan for say 15 per cent of India’s future energy needs coming from carbon-free technologies.So what are the choices? Wind power is a reasonably mature technology. India, with its installed capacity of 7,600 mw, is the fourth largest user in the world. Wind power potential is estimated at 45,000 mw. However, it is location-specific and intermittent. Wind speeds here are lower than those in Europe and consequently turbines operate at about 20 per cent load factor. If India achieves the estimated potential of 45,000 mw, wind can generate about 100 billion kwh — which is less than 1 per cent of desired supply. Wind will, therefore, remain a marginal player.Then there are bio-fuels. Oil-bearing crops such as jatropha and mahua can be used to produce bio-diesel. Likewise, ethanol can be produced from sugarcane juice, molasses and sweet sorghum. An enticing option would be to produce fuel from waste cellulosic biomass such as rice husk and sugarcane bagasse, although the technology is yet to be commercially proven. However, large scale bio-fuel production requires careful planning. Use of land for bio-fuels should not in any way compromise food grain production. India has an estimated 30 million ha of cultivable wastelands. Using 20 million ha for cultivating oil-bearing crops can produce about 25 million tonnes of bio-oil equivalent to 300 billion kwh of energy. Add to this another 100 billion kwh from ethanol, and the total contribution of bio-fuels will be about 2 per cent of India’s energy supply.India’s hydro-electric potential is estimated to be 84,000 mw. The present generation capacity is about 34,000 mw operating at an average 29 per cent load factor. Most of the untapped potential is in Arunachal Pradesh and it is not clear how much of this can be tapped, given the social problems of rehabilitation. If India can achieve the full potential of 84,000 mw, it will generate about 400 billion kwh — 2 per cent of the total.The one source of energy India has in abundance is coal. It accounts for 51 per cent of power supply. Coal will certainly continue to dominate India’s energy mix in the near term. However, every kwh of electricity from coal also releases about 1 kilo of carbon dioxide into atmosphere. An emerging option is to capture these emissions.This sequestration technology could double costs.India’s installed nuclear power is 4,120 mw — less than three per cent of electricity generation. Domestic uranium reserves being limited, India is pursuing the three-phase programme, with the objective of developing breeder reactors using plutonium and later thorium technology. The proposed Indo-US nuclear deal could provide the opportunity to import ‘light water reactors’ with fuel. India could then gain 24,000 mw from this route by 2030. Large-scale deployment of breeder reactors is still years away and depends on the success of the prototype. Most parts of India receive a good average of solar radiation of 5-6 kwh Therefore, solar power generation over an area of 20 million ha can generate about 24,000 billion kwh even at a modest 10 per cent efficiency. This is more than India’s expected total energy supply and several times the desired carbon-free energy. Solar energy appears to be a vital component of a long-term solution to the climate problem. Unfortunately, it continues to be prohibitively expensive. Solar thermal power using concentrators is another attractive option for utility-scale power generation. A single stretch of land measuring 20 km x 20 km, say in sun-drenched Ladakh, can generate over 20,000 mw of power contributing 50 billion kwh of energy (eight coal power plants). India should use all the resources if it has to generate a “reasonable” fraction of carbon-free energy. The writer is director, Centre for Study of Science, Technology and Policy, Bangalore anshu@cstep.in
