CEE April-June 2012

CASHING IN ON ASH Scope for better compliance with MoEF guidelines Dependence on coal-based power involves high environmental costs. Generation companies not only need to control emissions, but also ensure fly ash utilization. The major environmental impacts of fly ash are air and water pollution, and land Of the 31 gencos covered in the study, six achieved ash utilization of 100 per cent and above. Achievements in excess of 100 per cent are due to power stations utilizing ash stored from the previous years. This also explains the exceptional 913 per cent ash utilization level of KBUNL's Muzaffarpur power plant. The power station utilized ash degradation. Besides addressing environmental .--------- ------------, issues, modern fly ash utilization practices reduce utilities' land requirements. It is estimated that about 40,000 hectares of land area is occupied for conventional ash disposal. Though policy guidelines stipulating the targets for utilization are in place, not many plants have achieved them. Therefore, regular monitoring is important in this regard. All power stations that started operations before November 3, 2009 should have achieved at least 60 per cent of fly ash utilization by now. The cut-off date is based on a notification by the Ministry of Environment and Forests (MoEF). The policy also requires that the unutilized fly ash against the targeted level should be utilized in addition to the corresponding targets for those years. Similarly, stipulations have been prescribed for plants commissioned after November 3, 2009. The Central Electricity Authority (CEA) recently released a report on fly ash utilization at 88 coal– fired power plants in the country. The following are the highlights of the report: Status The CEA's study covered 88 power stations aggregating 80,458 MW of capacity as of 2010 - 2011. During the year, these plants consumed 407.61 million tonnes (mt) of coal, with an average ash content of 32.16 per cent. These plants reported 131 .09 mt of total ash generation. The ash utilization level stood at 55.79 per cent. Utility-wise, ash utilization varied from over 100 per cent to as low as 0.33 per cent. Utilities reporting ash utilization of 100 per cent and above include Kanti Bijlee Utpadan Nigam Limited (KBUNL), the Gujarat Mineral Development Corporation, the Tamil Nadu Electricity Board, Torrent Power Limited , CESC Limited and Gujarat Industries Power Corporation Limited. Also striking is the fact that NTPC Limited, the largest power generation company, reported ash utilization at only 55.9 per cent for the 15 projects covered under the study. Fly ash utilisation by user industries Bricks and tiles: 6.30 -~ ... Source: CEA accumulated over the past few years for land development for setting up two 195 MW units. Low– and medium-concentration slurry disposal is the most common form of ash disposal in ash ponds by various utilities. Of the 88 power stations reporting data for ash utilization, 57 achieved ash utilization of 50 per cent or more as of 2010-11. Ash utilization at the Hissar, Amarkantak, Anpara A and B, and Santaldih stations was negligible. This shows the gap in compliance with the MoEF's regulations on ash utilization. On the other hand, 13 stations reported ash utilization of 100 per cent and above. The long-term trend shows an increase in fly ash utilization at coal-fired power stations. Between 1996-1997 and 2010-11, fly ash utilization witnessed a compound annual growth rate of 13.36 per cent. However, year on year, it declined in 2010 -11. This is an exception to the growing trend of fly ash utilization. Among other reasons, the data also includes two new coal-fired power plants, where ash utilization was nil. Another important factor is that the annual growth in ash utilization has not been uniform. For most years, the growth registered a decline. 47