Power generation: Coal’s the reality for now, global lessons in efficiency

Thermal units will persist as mainstay of the power sector in the foreseeable future. Focus should shift to making them competent.

Written by Anil Sasi | Published: December 2, 2015 1:28 am
A protester with a placard at a Global Climate March. Globally, the developed world has, by and large, signaled the intent to move off CO2-belching coal-fired power stations.  (Source: AP) A protester with a placard at a Global Climate March. Globally, the developed world has, by and large, signaled the intent to move off CO2-belching coal-fired power stations. (Source: AP)

At the 21st Conference of the Parties to the UN Framework Convention on Climate Change (UNFCCC), COP 21 in Paris, a resolution on limiting the use of coal across countries was one of the proposals put up for consideration. In the Indian context, this is of particular relevance as coal-fired power stations form the backbone of the Indian power generation sector and will continue to remain so in the foreseeable future, the Centre’s concerted efforts to ramp up renewables such as solar notwithstanding.

Globally, the developed world has, by and large, signaled the intent to move off CO2-belching coal-fired power stations.

Two nations, Japan and Germany, though are emerging as exceptions. In fuel-starved Japan, utilities are setting up a new wave of coal-fired stations as a replacement to many of their ageing coal units. According to data compiled by Kiko Network, a Kyoto-based environmental group, there are over 40 new coal-fired units slated for construction. By comparison, the coal-rich US has only one coal-fired project coming up — Southern Company’s Kemper project, a demonstration project for new carbon-capture technology.

Germany too had enunciated a broad roadmap of moving away from the dependence on coal. But accompanied by its more recent plans to phase out nuclear power, new estimates show that Germany’s lignite and anthracite coal power output in 2014 had rebounded to its highest level in more than 20 years, something that researchers blame on cheap CO2 emissions permits and the winding down of nuclear projects.

In end-2013, generation surged to 162 billion kilowatt hours, the highest level since reunification in 1990 when Germany’s coal-fired power stations produced nearly 171 billion kilowatt hours of power, largely on account of many old eastern German plants that were still in operation, according to figures from AGEB, a group of industry associations and technical institutes.

In India, there is no escaping the reality that coal will continue to be the mainstay of the power generation sector. An area where India can hope for lessons from countries such as Japan is in the efficiency of coal plants, which, in India, comes in at about 25-30 per cent as compared with an average of over 35 per cent in the US. Japan’s coal plant operational efficiency is above 40 per cent, according to an analysis by Dutch consultancy Ecofys. J-Power, a Japanese state-owned utility until 2004, claims to have the most world’s most efficient coal plant at nearly 45 per cent.

In the United States, the Department of Energy is heavily promoting the benefits of integrated gasification combined cycle or IGCC — a technology that gasifies coal to make synthetic gas that can generate electricity — as a means of ensuring viability of coal at a time when environmental regulations become more stringent. Benefits include the possibility of IGCC units being retrofitted to capture carbon dioxide, burn a range of imported coal feedstocks and use less cooling water.

That in India, thermal will continue to be the mainstay of the power generation sector is a given, despite the government’s overt focus on solar. This is notwithstanding the latest round of solar auctions in India last month, where US renewables major SunEdison bid a very low tariff of Rs 4.63 a kWh for 500 MW in an solar park being developed by NTPC Ltd in Kurnool, Andhra Pradesh. Cost, though, is not the biggest problem in scaling up renewables such as solar. A bigger problem is how to handle a higher share of solar or wind in terms of its impact on managing the grid.

In India, at over 36,000 MW, renewable energy currently contributes nearly 15 per cent of the country’s total installed electricity generation capacity. If the capacity addition of renewable projects such as solar and wind were to happen as per plans, this number is expected to go up to 1,75,000 MW by 2022. That’s where the problem could lie.

The steady ramping up of green power — solar, for instance, was just 2 MW in 2010 but is now over 4,000 MW — does go a long way in ensuring some degree of leverage for India at climate talks, but simultaneously poses a serious challenge for grid managers. The availability of solar and wind energy is largely determined by the weather conditions, and therefore characterised by strong variability. As a result, power generation from these sources cannot easily be matched to the electricity demand, like power generated from conventional plants such as coal-fired units and gas stations. Integration of large amount of fluctuating RE in the grid is a serious technical challenge for grid managers to ensure smooth operations of the Indian grid — the fifth largest in the world. To compound matters, RE generation forecasting in the country is in its early days.

A more viable strategy might be to focus on improving the efficiency of the country’s coal-fired power plants, replacing older coal plants with supercritical units and pushing for newer technologies such as coal gasification to breach the viability barrier by taking a leaf out of the experiences of Japan, Germany and the US. A renewed push for hydro is simultaneously needed to beef up the green component in India’s base-load capacity.

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