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India happens to be fourth coal dependent (51.4% of primary energy) country in the world. Coal would continue to dominate for some more years as the projected coal reserves are likely to last for the next 100 years.

India, with about 80 coal-fired power plants and needing more electric power depends, on cheapest and easiest fuel (Coal) available to generate electricity. Of the current installed capacity in India, around 64.7% is accounted by thermal with second larger contributor being Hydel (24%). Even among the thermal it is predominantly coal which, is likely to stay as the main option for at least some more time until replaced by another equally competitive fuel.

Coal reserves in India accounts for about 6.7 percent of the world's known reserves. Despite sincere efforts on increasing renewable and nuclear, they may have to contend with the small player tag for the foreseeable future. The renewable contribution could improve to about 10 percent by 2012 from the current 8 percent. Addition of about 78,000 MW capacities over the next five years could attract a conservative estimate of $78 billion.

The sub critical technology has been serving the sector through the progressive capacity additions over the last six decades rising from a mere 1713 MW in 1950 to the current 1,53,694 MW (October, 2009). The reservation over advanced technologies or an alternate for sub critical seems difficult to comprehend while the world has witnessed sea change in the outlook on thermal and in particular, coal based generation.

China has the world's third-largest coal reserves after the United States and Russia. China for example has forged ahead of India in the coal based generation. In fact, the progress has been so rapid that China outscores the carbon dioxide emissions of the United States. China's current use of coal is more than the combined usage of US, Europe and Japan. At the same time, China has over the last two years emerged as leading builder of more efficient, less polluting coal based power plants.

The potential efficiency of about 44 percent of the proposed new plants over the current less efficient plants in China -- 27 to 36 percent -- could account for more than one third reduction in the GHG emissions. In view of the heavy dependency on coal in China, the GHG contribution even from the efficient coal based units would be twice that of gas based units. China has doubled its wind energy contribution over the last four years. China has also been paying attention to nuclear option. In spite of the developments the dependence on coal however, has not reduced.

Unlike China, US achieve around 40 percent efficiency of the most efficient coal based power plants.

China, through 'Ultra Supercritical technology using extremely hot steam' has achieved highest efficiency. Many such plants cumulatively has contributed to cost reduction to the extent that it is one third less than a less efficient coal based power plant in the united states.

While improved Coal based power plants definitely score over unstable gas prices, there has been a focal shift from base-load reliability to operational flexibility. The fine tuning to match new operational profile would provide huge financial benefits.

Although there are opportunities to enhance 'Efficiency' in coal based power plants, it is prudent to look at a few of them to register their advantages in the current and modern context of climate change. Power producers have of late, realized the importance of efficient operation as a meaningful exercise of their Corporate Governance. The developing nations while embracing such an adoption could benefit from the experience of developed nations in avoiding unsuitable options.

Advantages of Energy Efficiency improvement

Thermal power plants, backbone of the electricity systems converting heat energy into electrical energy records efficiency between 30 & 50%. Consequently, the balance heat gets dissipated into the atmosphere. However, efficiency based on laws of physics, is related to the fact that only a fraction, depending upon the type of power plant, of energy can be converted to electricity.

Massive demand for energy in China & India and critical challenges of climate protection warrant concerted effort on Energy Efficiency. The current trend of oil and gas import would inevitably result in CO₂ emissions until 2030 according to International Energy Agency (IEA) report on world energy. It is therefore imperative that governments alter policies now and companies begin to concentrate investment in more energy-efficient technologies.

The option of looking at one concrete solution to most dependable coal is unfortunately not viable and therefore, one has to evaluate and implement all the possible options simultaneously to achieve cumulative benefit. Power generators and Consumers together have equally significant roles to play in combating the energy crisis and avoid carbon dioxide build up in the atmosphere. The combination of power usage reduction (consumers end) and improved efficiency of the generating units would undoubtedly make precious energy available for industrial requirement and economic growth. Preventing energy waste assuming household responsibility now, may have been triggered either owing to selfish motive of reducing electricity bills or could have been environmental impulse.

Considering the demand for power in India, commissioning new plants at approximately Rs. Four billion per MW could prove a costly proposition, at this juncture as the simpler solution of making considerable amount of power available through energy efficiency improvement, could be an attractive option. In fact, one percent efficiency improvement would render a reduction of about 3% coal consumption and a consequent emission reduction as well. (Specific Coal Consumption being 650 kg per MW per Hour -- i.e. 4.62 Million Metric Tons for a 1000 MW power plant operating for 7000 hrs annually)

Need for Energy Efficiency improvement

It is indeed true that the replacement of fossil fuel which enjoys a long history may not be easy. However, proper evaluation of an alternate source in combination with Energy Efficiency measures both at the generating and consumer ends would result in substantial benefits. Although European community may be contemplating renaissance of nuclear power, renewable haven't fared badly in Asia over the last decade.

The performance of a power plant can be expressed through some common factors as heat rate (energy efficiency); thermal efficiency; capacity factor; load factor; economic efficiency and operational efficiency

The power plant efficiency mainly centers around Temperature (heat derived through coal combustion) and pressure (steam derived through water) optimization for a given technology. Superior technologies understandably present better efficiency over subcritical pulverized coal power generation.

The global approach in achieving this goal has been different through adoption of either improvement or conservative measures. As an example, the message that stems from California's experience is that "efficiency is the foundation of any effort to reduce reliance on fossil fuels." As a consequence of which, they succeed in - "Avoiding the need for 24 power plants" - . California further enacted laws to create a Renewable Portfolio Standard (RPS) directing investor-owned utilities to generate 20 percent of their power from renewable sources by 2010 and 33 percent by 2020.

Such a combination of Energy Efficiency supplemented by the Renewable energy has indeed become inevitable in India in view of the two recent announcements by the Ministry of Environment and Forests in their pro-active approach:

• India to set industry efficiency targets by December 2010
• National Ambient Air Quality Standards, 18th November, 2009

Current scenario and future options:

Operational efficiency is defined as the ratio of the total electricity produced by the plant over a period of time to the total potential electricity that could have been generated HAD the plant operated at 100 percent.

One of the power plants in India has been operating consistently at 100 % Plant Load Factor (PLF). It would therefore be ideal to add substantial amount of power emulating good practices prevalent at this power plant (Coal based being 81,356 MW at the current installed capacity) without direct investment and avoiding associated environmental consequences (During 2007 -- 2008 PLF of 101.8% of Dadri TPS (210 MW) of NTPC was the highest among all central sector units. PLF of 100.15 % of Kota TPS of RRVUNL was the highest among all state sector unit). Just 1% improvement in the national PLF of 75.95 % as of Sept.2009 would make 814 MW of power available and about 4070 MW if it enhances to 5%.

The factors like heat rate, thermal efficiency, capacity factor, load factor, economic efficiency and operational efficiency seem to have close interrelationship. A positive change empowering and encouraging all areas of the power plant -- operation, maintenance, capital project analysis etc -- to focus on heat rate improvement would facilitate sustenance of comprehensive heat rate and consequently benefit the overall functional efficiency of the power plant.

Reduced energy (fuel) consumption per kWh of energy generation is in essence Energy efficiency measures in a thermal power station. The energy efficiency measures need be effected through major resources -- Coal & Water and novel options.

• The power plants have an option of achieving this either through superior quality coal or Pulverised coal combined with biomass energy. In addition, efforts towards minimizing the auxiliary power requirement would benefit the power units not only financially but even from the emissions into the atmosphere.
• Clean coal technologies may take some time before a convincing dent in the energy sector. Since tropical country like India is blessed with a variety of non-edible oil species, bio-fuel spray would enhance the calorific value of pulverized coal substantially and consequently reduces fuel and gaseous emissions, as brought out in one of my earlier paper. India could in reality, become prime exporter of 'bio-fuel', the potential replacement for oil sooner or later.
• Combination of the conventional power generating units with renewable wherever feasible has been an ideal option of not only the fuel consumption but also the consequent carbon dioxide emissions. Adding 'Solar Energy' to fossil fuelled power plants could reduce fuel costs and emissions according to an announcement of Electric Power Research Institute (EPRI). Steam generation by a solar thermal against conventional fossil fuel-powered steam cycle could offset some of the fuel required to generate electric power, in a gas based power plant. 'Hybrid Power Plants', as they are referred to will combine the low-cost reliability of existing fossil power plants with the environmental benefit of renewable and help companies meet regulatory mandates to reduce air pollutants and greenhouse gases with renewable energy.
• Renewable, whose share of electricity generation market is growing fast will play a pivotal role in the coming years.
• According to a recent report, nuclear power is not the way to go If, U.S. wants to help stop global warming,
• The Environment California Research & Policy Center concluded that launching a nuclear power industry nearly from the ground up is too slow and an expensive a process. They feel that Energy efficiency standards and renewable energy options are better solutions.
• The $600-billion upfront investment necessary for the 100 reactors would slice out twice as much carbon pollution in that period if invested in clean energy. Given the costs of running a power plant, clean energy could deliver five times as much progress per dollar in lowering pollution.
• India hopes to set up by December next year energy efficiency targets for more than 700 industrial units, which account for 40 percent of India's fossil fuel use.
• Bureau of Energy Efficiency, said 714 energy-intensive industrial operations had been identified from nine sectors, including power and cement which would be measured on efficient use of energy.

Conclusion

The G8 and accompanying Major Economies Forum pledged to cut carbon dioxide emissions by 80% by 2050 (UK will meet a cut in emissions in its carbon budet of 34% on 1990 levels by 2020) and limit global temperature rise to a maximum of 20 C above the pre-industrial levels including developing countries. UK in fact looks ahead for 'Low-Carbon' future. The pressure on the global community has never been so intense as it is now, while the "Copenhagen Conference" is just around for proper road map beyond 2012.

The Consortium of 12 companies including Siemens, ABB, Deutsche Bank, E.on, and RWE agreed to move forward with DESERTEC (Sun in Sands) -- 400 billion Euro project to build 'Solar Hub' in the Sahara and transmit the power to Europe.