Bratin Roy | VP - Industry Services, TÜV SÜD South Asia
India has embarked on an ambitious solar mission, besides focus on other renewable energy sources. How this move is expected to affect the future of coal as a source of power generation?
Currently, the government´s goals for environment are more focused on the deployment of renewable energy technologies, including the ambitious solar mission and simultaneously improving energy efficiency. However, the plans for exponential development of renewable energy do not signal a move away from coal; concurrently the government has announced plans to almost double its coal output to one billion tonnes by 2020 which is a positive indication to the future of coal as a source of power generation.
What are the environmental impacts of coal as a source of power generation? What are the better alternatives that are available, based on environmental impact?
India´s coal-fired electricity generation capacity is largely based on subcritical technology and is designed to use domestically-sourced coal. Although subcritical technology is relatively cheaper compared to other available technologies, it uses more coal and generates more CO2 emissions. From 2017, all new coal-fired projects developed in India will be required to use supercritical technology or better. Newer coal-fired technologies operate at a higher efficiency, which means that they consume less coal per kilowatt hour generated, thereby improving environmental performance. They are also often referred to as High-Efficiency, Low-Emissions (HELE) coal-fired power generation. Increasing the efficiency of a coal-fired power plant by 1 per cent can reduce its emissions by 2-û3 per cent.
Are there any modern technologies that could help reduce the environmental impact of coal as a source of energy and how?
Pulverised Coal Combustion (PCC) is the most common coal-fired technology deployed worldwide. There are a few PCC technologies being used that have markedly different efficiencies, costs and pollution outcomes. The efficiency of a plant refers to the electricity produced for a particular heat input. In coal-fired power plants, this depends on the temperature and pressure of the steam generated in the boiler during combustion. The efficiency of a plant is enhanced when both temperature and pressure are increased.
Subcritical technologies are most commonly utilised by coal-fired plant. It has the lowest efficiency (around 30 per cent) of the available technologies. Subcritical plants generally have low capital costs, which supports its large-scale uptake.
Supercritical technologies achieve efficiencies of around 40 per cent. The capital cost of these plants is higher because it must use materials with a greater heat tolerance in the boiler. Supercritical plants use less coal and generate less CO2 than subcritical plants.
Ultra-supercritical and Advanced ultra-supercritical plants operate at efficiencies between 45-û50 per cent. The capital cost of these plants is high because they must use advanced materials (with high nickel content) in the boiler and also use less coal and emit less CO2 than supercritical plants. Plants that utilise supercritical technologies and above require higher energy coal, with low ash content, to operate optimally.
Which is the best source of energy considering the economics and cost of electricity?
Currently, renewable energy costs are generally higher than that of fossil-based and nuclear energy. In addition to this, unlike well-established conventional designs and technologies, the advancement in different RE technologies still requires substantial investments and research and development. In future, across the globe, including India, the price of coal-based electricity can nearly double due to government imposed cost on CO2 emissions. However, we should remember that low-cost electricity generation is extremely important to the growth of economy. It increases income and employment in all sectors, the purchasing power of the consumer, and makes manufacturing more competitive. Renewable power certainly can supplement conventional power, and its use will likely continue to steadily grow.
Coal supply situation has improved, reversing the acute shortage scenario seen about two years back? Do you see any revival of interest in setting up of new coal-based power plants?
The environment is definitely conducive, however, there are various other factors which will also play an important role to see a revival of interest in setting up new coal-based power plants. Coal block auctions may have addressed fuel supply woes to some extent, but private power generators may have to face tariff under-recovery to some extent.
Auctioning of coal linkages will only add further pressure on power generators as competitive prices will put pressure on their already debt-laden balance sheets. Issues like land acquisition, forest clearance, environmental clearance and promptness and transparency are still the stumbling blocks, while handling these issues will be imperative to create a positive investment environment.
What is the current pipeline of new generation capacities coming up and do you see any change in the shares of different fuel sources in the next five years?
India is likely to add 600 GW to 1200 GW of additional new power generation capacity before Year 2050. The target for 12th Five-year plan is that of 118.54 GW out of which 88.54GW is to be produced from conventional sources while the remainder is to be generated from renewable energy. The government´s plan is not only on target, but it is likely to exceed the estimated capacity. There is every possibility that shares of renewable sources will increase significantly than planned in next five years and also than what was assessed in the 12th plan. The government has set a target of 175 GW of renewable energy capacity by 2022, which includes 100 GW of solar power, 60 GW of wind power, 10 GW of biomass-fired power and 5 GW of small hydro power.