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No lessons being learnt from underperforming hydropower projects

By Himanshu Thakkar and Bipin Chaturvedi

Only four of the 12 hydropower projects in the Northeast generate at their projected 90% dependability or higher. The rest are underperforming miserably. Regardless, several big projects are under construction in the Northeast. Why don’t the stakeholders analyse the performance and impact of large hydro projects before promoting more of them?

Large hydropower projects in Northeast Inbdia

Northeast India is viewed as having huge hydropower potential, up to 60,000 MW or more. A number of big projects are under construction or in various stages of active consideration. This has led to serious questions on issues ranging from governance to environment, and social and economic impact. The projects are also likely to affect people’s capacity to cope with climate change, considering their dependence on natural resources, including forests, rivers, and biodiversity.

Considering the geo-seismic situation and fragile erosion-prone mountains of the eastern Himalayas and its silt-laden rivers, the appropriateness of large hydro projects has come under fresh scrutiny. Huge movements have built up in Assam, Arunachal Pradesh, Manipur and many other parts of the Northeast in view of the serious  downstream impact of these projects, including changes in the flood characteristics of rivers. Poor appraisal and even poorer compliance are characteristics of such projects in India; in the Northeast the situation is much worse.

In this context, it would be relevant to see what the hydropower generating performance of existing projects has been. All the figures used here are from the Central Electricity Authority, the Government of India’s premier technical monitoring body in the power sector. The figures have been taken either from the CEA website or from CEA publications, or have been obtained under the Right to Information Act.

The total installed capacity of large hydropower projects in the Northeast is 1,701 MW in the year 2010-11, up from 215 MW in 1985-86. The following chart shows how capacity has been increasing in the region over the past 25 years. The graph is already steep compared to the rest of India, and is likely to get steeper considering the large number of projects under construction and in the pipeline.

Arunachal Pradesh

The installed capacity of hydropower projects (HEPs) in Arunachal Pradesh is 423.5 MW. Of all the projects in the state, only Ranganadi (405 MW) is a large hydropower project, under the central sector (NEEPCO); the rest are small HEPs. In the state sector, Arunachal Pradesh has no large HEPs (more than 25 MW installed capacity), only four small HEPs. These projects are Tago (4.5), Nuranang (6), Kambang (4), and Sippi (4).

The table below is an analysis of large HEPs in Arunachal Pradesh, in terms of best and worst performance according to million units (MU) (one unit equals one kilowatt-hour, or power that one KW can generate if operated for an hour) per MW for the stated period for which the project has been operating in the last 25 years since 1985-86. The projected 90% dependable figure is also given. Projects are given techno-economic clearance based on this projected 90% dependability figure, with the promise that it will generate that much power in 90% of years. We have assessed the actual 90% dependable generation based on the actual generation figure and then compared that with the promised 90% generation. Based on this, we have assessed the percentage of underperformance. The last column gives the percentage of years in the study period in which actual generation is greater than the promised 90% dependable generation. This figure should be 90%, or higher. The description of the table is valid for each of the states in the Northeast for which the analysis is given below.

In the case of the Ranganadi project -- the second largest operating hydro project in the region -- the percentage is zero; the project has never achieved the generation level it should have achieved in nine out of 10 operating years! Dismal performance indeed!

Project
(installed capacity)
No of data years Best-worst performance (MU/MW) Average performance (MU/MW) Design 90% dependable generation (MU)-A Actual 90% dependable generation (MU) % of
under
performance
% of years when actual generation more than A
Ranganadi (405) 10 4.05-0.47 2.94 1,876 958 48.93 0

Assam

The installed capacity of large HEPs in Assam is 325 MW; among them the Karbi Langpi (100 MW) is in the state sector (APGPCL) and Kopili (NEEPCO) is in the central sector. The 90% dependable generation figure for Karbi Langpi looks low when compared with other such projects. This makes its performance look rather respectable. The project has only been operating for four full years so far. The longer-operating Kopili project is underperforming by a huge 44.5% compared to its promised generation figure.

Project (installed capacity) No of data years Best-worst performance (MU/MW) Average performance (MU/MW) Design 90% dependable generation (MU)-A Actual 90% dependable generation (MU) % of
under
performance
% of years when actual generation more than A
Karbi Langpi (100) 4 4.95-4.00 4.29 390 407 +4.36 100
Kopili (225) 23 6.53-2.61 4.16 1,153 569 44.49 28.57
Total (325) 23 6.53-2.61 4.17 1,543 976 36.75 -

Manipur

There is one large HEP in the state -- NHPC’s Loktak (105 MW). The project has performed below promises by over 17%.

Project (installed capacity) No of data years Best-worst performance (MU/MW) Average performance (MU/MW) Design 90% dependable generation (MU)-A Actual 90% dependable generation (MU) % of
under
performance
% of years when actual generation more than A
Loktak (105) 26 6.72-3.57 4.93 490.29 405 17.35 69.23

Meghalaya

The installed capacity of four large HEPs, the largest number in the region, in Maghalaya is 206 MW. In addition, Umiam ST-II (18) and Umtru (11.2) are in the state sector (MeSEB). Two of the four projects are heavily underperforming; the rest are performing close to their promised generation. Overall performance of the state is dismal, with over 35% underperformance.

Project (installed capacity) No of data years Best-worst performance (MU/MW) Average performance (MU/MW) Design 90% dependable generation (MU)-A Actual 90% dependable generation (MU) % of
under
performance
% of years when actual generation more than A
Kyrdemkulai (60) 26 3.42-1.95 2.65 118 134 +13.56 92.3
Umiam  ST-I (36) 25 8.92-1.31 3.63 128 129 +0.78 88
Umiam ST-IV (60) 19 4.09-00 2.57 324 118 63.58 0
Khandong (50) – CS 26 5.84-0.34 4.02 242.63 146 39.83 19.23
Total (206) 26 3.77-2.13 3.18 812.63 527 35.15 -

 
Nagaland

The installed capacity of HEPs in Nagaland is 99 MW, out of which Lokkim-RO is a small HEP that comes under the state sector. The only large HEP in the state is Doyang (75 MW), which is under the central sector (NEEPCO). Even though the 90% dependability figure for the project is low, the project is heavily underperforming compared to even this lower promised generation figure.

Project (installed capacity) No of data years Best-worst performance (MU/MW) Average performance (MU/MW) Design 90% dependable generation (MU)-A Actual 90% dependable generation (MU) % of
under
performance
% of years when actual generation more than A
Doyang (75) 10 3.57-1.59 2.55 227 141 37.89 40

Tripura

The installed capacity of the huge Gumti HEP, which is a storage dam with live storage capacity of over 250 million cubic metres, is 15 MW. This project comes under the state sector. Because the project has a very low 90% dependability generation figure, it is, not surprisingly, able to achieve generation close to it.

Project (installed capacity) No of data years Best-worst performance (MU/MW) Average performance (MU/MW) Design 90% dependable generation (MU)-A Actual 90% dependable generation (MU) % of under
performance
% of years when actual generation more than A
Gumti (15) 24 4.67-2.4 3.46 38 40 +5.26 95.65

It should be added here that this dam is a fit case for decommissioning, considering the small installed capacity for a dam that has submerged 4,634 hectares of land in the Raima valley in South Tripura district, bordering Bangladesh. As Subir Bhowmik says: “This was one of the most fertile valleys in an otherwise hilly state where arable flatland suitable for wet rice agriculture is so scarce.” He goes on to narrate how the project was fiercely opposed and was subsequently also a breeding ground for insurgency groups. If the dam is decommissioned, Tripura will not suffer power problems as it already has an operating gas-based power capacity of 232.5 MW, which is far in excess of the state’s requirements. At least 25,000 tribals can be resettled on land that would be available if the dam were decommissioned. In fact, in the last state elections, this was a major election issue endorsed by all except the ruling alliance.

Sikkim

The installed capacity of HEPs in Sikkim is 602 MW. Rangit (60) and Teesta (510) are large HEPs that are under the central sector (NHPC); the rest are small HEPs. Sikkim has the highest hydropower installed capacity among all the northeastern states; it also has the largest number of under-construction hydro projects. Sikkim state sector has L Lagyap (12 MW), U Rognichu (8 MW), Moyangchu (4 MW) and others (8 MW).

 

Project (installed capacity) No of data years Best-worst performance (MU/MW) Average performance (MU/MW) Design 90% dependable generation (MU)-A Actual 90% dependable generation (MU) % of under
performance
% of years when actual generation more than A
Rangit (60) 11 6.18-3.35 5.50 349 304 12.89 33.33
Teesta (510) 4 5.15-3.70 3.62 2,573 2,598 +0.97 66.66
Total (570) 11 6.18-3.35 5.26 2,922 2,902 0.68 -

Mizoram has no large HEPs.

Regional analysis

In the graph below we have plotted the MU power generated per MW installed capacity for all projects in the Northeast, over the last 25 years. Even though the graph is flat, we can see that generation in recent years has been below 4 MU/MW, about 19% below the peak of 4.95 MU/MW reached in 1993-94. The 90% dependability figure for the states is 4.65 MU/MW, as can be seen from the table that follows, and during the entire 25-year period, the states crossed this figure just once, when they should have achieved it for at least 22 years. It is clear that power-generation performance in the Northeast is pretty dismal and has shown no signs of improvement in the last 25 years.

The table below shows the state-wise performance of large hydropower projects in the northeastern states, taking the analysis from the state-wise details given above.

Project (installed capacity) Best-worst performance (MU/MW) Average performance (MU/MW) Design 90% dependable generation (MU)-A {MU/MW} Actual 90% dependable generation (MU) % of under
performance
Arunachal Pradesh (405) 4.05-0.47 2.94 1,876 {4.63} 958 48.93
Assam (325) 6.53-2.61 4.17 1,543 {4.75} 976 36.75
Manipur (105) 6.72-3.57 4.93 490.29 {4.67} 405 17.35
Meghalaya (206) 3.77-2.13 3.18 812.63 {3.95} 527 35.15
Nagaland (75) 3.57-1.59 2.55 227 {3.03} 141 37.89
Tripura (15) 4.67-2.4 3.46 38 {2.53} 40 +5.26
Sikkim (570) 6.18-3.35 5.26 2,922 {5.13} 2,902 0.68
Total (1,701) 4.95-2.71 3.72 7,908.92 {4.65} 5,949 24.78

It is clear that only four of the 12 projects in the Northeast generate at projected 90% dependability or higher. The total capacity of these four projects is 221 MW, which is less than 13% of the region’s hydro installed capacity of 1,701 MW. So, 87% of installed capacity and 67% of projects generate at less than the promised generation level. It may be noted that underperformance has nothing to do with the age of the project; not-so-old projects like the 405 MW Ranganadi and the 75 MW Doyang HEPs are hugely underperforming. For the region as a whole, the underperformance is around 25%, and if we see the generation figures for the last few years we see no improvement.

The trouble is, the concerned agencies at the state and central level do not even carry out this sort of analysis, let alone attempt to improve performance. It would be better for the state and central governments, operators and those advocating more hydro projects in the region to try and understand the reasons for the huge underperformance, and try to figure out how things can be improved.

There are two broad categories of reasons for why this is happening. Lack of proper repair and maintenance, lack of attempts at power optimisation (for example, in the case of multiple projects on the same river) and lack of catchment area treatment to reduce siltation is one group of reasons that, if tackled properly, could significantly improve performance. The second set of reasons relates to flawed appraisals, decision-making and governance mechanisms due to which unviable projects or capacities are set up. For projects already up, this may not help immediately except in cases like the Gumti where a decision about decommissioning could be taken. Lessons learnt through analysis make for better decisions in the future.

Regarding supply-side options for the region there is the excellent example of Anjaw district in Arunachal Pradesh (http://timesofindia.indiatimes.com/city/guwahati/Anjaw-shines-in-hydro-power-sector/) where four sub-MW (less than one MW) capacity hydro projects, five sub-MW hydro projects under construction, and one 16 MW hydro project will make the district produce more power than it needs. Northeast India has huge scope for sub-MW projects, which are appropriate for the region considering its dispersed populations. Although these projects too have their local impacts, they are on a much smaller scale compared to large projects; and the impacts are easier to assess, compensate and adapt to. They can also involve local communities right from the planning to the operation stage and will have a much smaller ecological and climate-related footprint. Unfortunately, no serious attempts are being made to go down this path.

(Himanshu Thakkar and Bipin Chaturvedi are with the South Asia Network on Dams, Rivers & People)

Infochange News & Features, January 2012