To dam or not to dam!

The 17th Electric Power Survey projections show that by 2012, peak energy demand in India will double from that of base year 2003/04. From 362,799 million units, the country’s annual energy consumption will be 755,847 million units. This is based on the assumption that government is able to deliver its power to all by 2012, and that utilities are able to contain their T&D losses.

The earlier survey had envisaged an addition of 1 lakh MW by 2012. It had called for a 60:40 ratio of thermal to hydel, as against the present 75:25, for optimum utilization of installed capacity. Of the additional requirement, some 16,553 MW is expected from hydro.

There is identified potential of over a lakh MW of hydro power in the country. So where is the problem?

Environment concerns stalk hydropower in India, as also anywhere else. This is because most of these are in fragile, mountainous regions where the potential for eco-damage is most. There is worry about what damming could do to the natural flow of rivers which keep large tracts of land fertile besides supplying water. Submergence and rehabilitation is a big worry. Tectonic considerations add to the woes.

It is the environmental clearances that deter potential investors from hydro sector. Often these take a long time. The technical due diligence studies calls for data like rainfall, water, etc from the last 20 years which is often unavailable. The flow data of rivers is often very old and leads to storage capacities never getting filled. Silt accumulation in reservoirs is another problem that deprives land downstream of nutrients.

It is to address this lack of enthusiasm that government policy has been drafted to make life easy for investors. The power generator has to invest only 30 percent of capital as equity while the rest comes as loan for which government pays interest! The investor gets annual fixed charge if the generation goes beyond a certain capacity index. Here, experts feel that capacity is not gauged properly beyond machinery availability and can boast a big number even when generation is very low.

While there are 55 hydro projects in different phases of construction and planning, many face opposition from environment groups. EIAs are done without sufficient attention to facts. In many difficult terrains, getting the data for EIAs is a laborious and complex step. Inefficient projects based on outdated data have meant profits for investors without any significant energy generation.

In such a scenario, more power generators are going in for run-of-the-river projects. These are projects that seek not to dam the river but to merely divert water to fall at a gradient, generate power, and return the water to the river downstream.

However, some amount of storage is required to generate sufficient flow and pressure. This water is sent down a tunnel, ranging in kilometers, before it falls on the turbines. The fact that there is no limit for storage to be defined as run of the river has meant that certain liberties are taken.

Also, there is no submergence of land in r-o-r projects.

But such projects could end up with rivers drying up in the patches where diverted. And also cause disturbances in the fragile eco-system around, by way of constructions, roads, etc.

The Pathrakadavu dam being pursued by Kerala in the Silent Valley periphery is being touted as a r-o-r project with minimal damage to the river or the forests. But viewed as a whole it lies very much in the once-envisaged wider boundary of the national park and has potential to cause considerable eco-damage. This is for a few hundred MW which can be had by addressing T&D losses, say activists.

What is the solution? Everyone wants power. With ‘dirty’ coal still being the dominant source for a few more decades at least, hydro power would seem a better option. It is clean and renewable and does not incur recurring costs, even if initial costs are high at about Rs 6 crore for one MW, and gestation period long. It has a long lifetime. True, the IPCC has raised doubts about how clean this source is by pointing that reservoirs are sources of methane, a greenhouse gas. But not many are willing to accept that.

Should we dam our rivers? Are big hydels the answer or smaller ones that do not have large storage capacity? Reservoir-induced seismicity and landslides has been evidenced at Idukki project which also caused drying of river Periyar downstream. But we need to acknowledge that dams with storage reservoirs do facilitate irrigation in many places.

Going for big or huge dams do have negative fallouts. Already there are concerns over China’s Three Gorges project which promises to deliver 84.7 bn KWh when completed next year.

Taking 17 years to build, costing $24 bn the dam is 185 mt high, 2309 m long and has 26 turbines. It has already displaced 1.3 million.

Evidences of landslides triggered by the damming construction activities, caving in of shores along the reservoir, pollution of the Yangtze river, etc are some of the concerns that predict major catastrophes ahead.

The project was meant to tame the river, increase river shipping and power generation.

Obviously, big means bigger risks even if it promises big power. Still, can we rule them out when the need for power is acute?

The prudent choice would be to look holistically at each project in terms of the need, economic feasibility, ecological damage and sustainability.