It's more than power ... it's ash

With the demand for power likely to go up, and the near total dependence on coal for meeting energy requirements, it is imperative that environmental issues, local and global, be taken into consideration. As it stands today, thermal power generation is responsible for large-scale ecological problems, says N.S.KRISHNAN.

THERMAL power generation has emerged as a Hobson's choice in meeting India's electricity needs. Even in thermal power generation, coal is set to be the leading fuel because of its abundant indigenous availability. The potential of hydro power which can contribute significantly to meet peak energy demand has got stunted due to many reasons, notably the rising resistance to the construction of large reservoirs. Prospects of growth in nuclear power generation or in development of non-conventional sources of energy are limited in the foreseeable future.

The Planning Commission has projected the demand for electricity to go up from 327 BKwh (Billion Kilo watt hour) to 505.1 BKwh in 2001-02, to 762 BKwh in 2006-07 and 1130.40 BKwh in 2011-12. With the predominance of coal based thermal power generation in the country (today 75 per cent of the installed capacity of about 100,000 MW is accounted for by coal) and the continued dependence on coal for meeting the energy requirements well into the future, it does not come as a matter of surprise for environmental aspects of coal based power generation to occupy public attention.

Compounding the environmental concerns over power generation is the phenomenal increase in indigenous coal production which the demand of the power sector calls for. Adopting the business as usual scenario, the Planning Commission has projected the coal requirements of the power sector to go up from 253.7 (MMT) million metric tonnes in 1994-95 to 359.6 MMT in 2001-02, 484.2 MMT in 2006-07 and 651.90 MMT in 2011-12. Over 75 per cent of coal is extracted through open cast mining which lays bare huge areas. The destruction of forest cover and the general disturbance of local ecology which coal mining causes are matters of common knowledge. It is not difficult to imagine the worsening of the situation in the next decade. Bihar, West Bengal, Madhya Pradesh and Orissa bear witness to the ecological damage already done and what is likely to happen in the future. The reclamation and restoration of mined out lands has received little attention. A national programme is called for to ameliorate these conditions.

Displacement of people by development projects is now receiving worldwide attention. There have been cases in India where communities have been displaced three times in their life time due to opening up of mines and setting up of pithead power stations. The Singrauli coalfields situated on the border of Madhya Pradesh and Uttar Pradesh and having some of the largest open cast coal mines in India and pithead super thermal power stations is an example of repeated displacement of local populations. The opposition to large dams is bound to extend to coal projects and power stations sooner or later on account of this human dimension. It's time that power planners woke up to this threat. Compensation and rehabilitation packages for the displaced people should reflect the concern and value attached to the travails and trauma of displacement.

The transportation of high ash Indian coals (ash content varying from 35 per cent to 45 per cent) over long distances due to the geographical distribution of the coal resources presents a picture of economic waste. The use of diesel or electricity to transport ash associated with coal and utilisation of scarce railway track capacity along with the myriad problems arising at the power generation end due to the presence of high ash amount to an abuse of economic resources. Pithead generation of power and its transmission to distant locations over High Voltage Direct Current (HVDC) transmission lines do take care of these problems to an extent, yet there are limits to such a strategy arising out of safety and security considerations, water availability at the pithead for power generation and cooling, and high air pollution levels at the pithead.

Coal beneficiation at the pithead should, therefore, gain currency. The Ministry of Environment and Forests, Government of India, has laid down that power stations situated more than 1000 km from pithead should use coal with ash not exceeding 34 per cent. Studies have brought out in quantitative terms the virtues of coal beneficiation. One study has shown that a power station located at a distance of 200 km from the coal source can break even in terms of costs and benefits involved in using beneficiated coal. It is heartening to see that power utilities, both in the public and private sectors, have become aware of the gains arising out of coal beneficiation in terms of reduced transportation costs and higher plant availability.

Moving on to the location of power stations, the first problem that arises is that of site selection. The importance of site selection from the environmental point of view cannot be overemphasised. Under the guidelines issued by the Ministry of Environment and Forests (MOEF), Government of India, dating back to 1987, the locations to be avoided are generally those near metropolitan cities, forest areas, places of wildlife interest, coastal zones, flood plains, sites of archaeological, historical or cultural interest etc. Despite such clear guidelines, proposals for setting up power stations are received in conflict of them. Examinations of alternative sites is more an exception than the rule with project proponents. Demands are often made for conversion of forest land to set up power stations knowing fully well that the Forest (Conservation) Act, 1980, under which clearance is needed, is a stringent piece of legislation that permits forest areas being put to non-forest uses only in exceptional cases.

Often, while selecting sites for power stations, not much attention is paid to local hydrology. The extraction of large quantities of water from surface or underground sources puts the power stations in direct conflict with the demands of the local population. The environmental guidelines of the Ministry of Environment and Forests discourage the choice of 'once through' systems and emphasise recycling and reuse of water. Looking to the competing demands for water and the fact that fresh water is becoming a scare resource, the hydrological aspect in locating power stations assumes paramount importance. Likewise, the quality limits set for water discharge, particularly the maximum temperature differential between the discharges and the receiving water bodies, need to be strictly adhered to in view of the anticipated adverse impact on aquatic and marine life.

Preservation of air quality is perhaps the single factor that is valued most by local populations living in the vicinity of power stations. Here again, strict emission and ambient standards have been laid down by the Pollution Control Boards. What seems to be lacking commonly in Environmental Impact Assessment studies is the absence of baseline ambient air quality data and related parameters like wind directions and wind speeds at the identified site. While at least three seasons data (winter, summer and monsoon) need to be gathered and isopleths based on expected emission from the power stations be computed for an area within a radius of 30 km around the plant, the tendency is to obtain quick clearance based on a single season's data. Often, even this single season data is found to be based not on observations taken at site but at a distant location where the Department of Meteorology has its monitoring facilities. Such 'quick fix' approaches born out of inadequate planning on the part of project proponents find encouragement from authorities who accord 'in principle' clearance based on scant data. This practice must cease.

The storage of ash, both bottom as well as fly ash, is a bugbear to the proponents of power stations. The collection of huge quantities of ash at power stations is inevitable due to the high ash content of Indian coals. The solution lies in coal beneficiation at the pithead, utilisation of ash in landfills, cellular brick making, use of ash as paving material on roads and as a soil conditioner. The role of the government is crucial to promote such uses of ash. The use of fly ash for making bricks has now become a viable commercial venture and plants have sprung up attached to some power stations. Cement plants have also come to use fly ash in cement making. However, these efforts are miniscule compared to the magnitude of the problem. Governmental action in the form of regulation banning digging of earth to manufacture bricks, mandatory use of power house ash in road laying, cement making, compelling government departments to use fly ash bricks in their construction works and extension of tax incentives is called for. It is gratifying to note that the MOEF has issued a comprehensive notification on September 14, 1999 prescribing phased utilisation of ash by power plants, mixing at least 25 per cent of ash with soil in the manufacture of clay bricks or tiles within a radius of 50 km of coal based power plants and calling upon the Central and State Governments to promote use of ash and ash based products in their constructions.

Along with local environmental aspects of coal based power generation, a look at international developments surrounding the use of fossil fuels would be valuable. Climatologists have noticed that the globe is getting warmer with the global temperature today being about 1'Celsius higher than what it was a century ago. Studies point out that while half this increase could be attributed to natural phenomena like volcanic eruptions which throw up large quantities of dust or sun spot cycles, over which man has no control, the other half is clearly accounted for by anthropogenic activities that release gases like carbondioxide and methane. These gases form a lid in the atmosphere trapping the heat released on the earth thus giving rise to a "greenhouse" effect. The burning of fossil fuels, particularly the use of coal in power generation, which releases carbondioxide has been held to be the main culprit.

Concern over global warming gave birth to the Framework Convention on Climate Change (1990) under which an obligation is cast on the developed countries to reduce their "green house gas" emissions below certain prescribed levels. The schedule for such reduction was agreed upon under the Kyoto Protocol (1995) which calls for a reduction in such emissions by at least 5 per cent below the 1990 levels by 2008-12. Eventhough neither the Convention nor the Protocol impose any restrictions on developing countries, there is a strong demand from the developed nations that the former should also undertake binding obligations. The pressure is particularly strong on the Newly Industrialised Countries (NICs) like China, India and Brazil. It won't be long before this clamour builds up to a crescendo. Evidence of this was available in the address of the U.S. President to the World Trade Organisation's ministerial conference in Seattle. The significance of this global environmental dimension to our power generation and economic growth needs to be appreciated.

Briefly, some of the initiatives that are called for to reduce greenhouse gas emissions in power generation would include improving plant utilisation capacities, adoption of clean coal technologies, integrated coal gasification and combined cycle generation, reduction in transmission and distribution losses, energy conservation and efficiency and demand management. Considerable interest is being evinced by many foreign countries in assisting India in introducing desired technological innovations. The U.S. Agency for International Development (USAID) is promoting actively clean coal mechanisms and clean technologies in India. We should see more of these efforts in the years to come. Lastly, since forests act as sinks of carbondioxide and help reduce its build up in the atmosphere, arresting the decline of forest cover and large scale afforestation would serve as cost effective solutions to combat global warming.

Looking to the country's almost total dependence on coal for meeting its energy needs, it would bear repetition that planners and operators of coal and power projects must pay their utmost attention to the environmental aspects, local and global, associated with coal mining and power generation. The warning signals are loud and clear.

The writer is Former Secretary, Ministry of Environment and Forests, Government of India.

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