1. What is the installed capacity of Tehri and Koteshwar Hydro Power Plants?

Installed capacity means the summation of the nameplate capacities of all units of the generating station or the capacity of the generating station as reckoned at the generating terminals, as may be approved by Commission from time to time.

Installed capacity of Tehri HPP and Koteshwar HEP are as under:
Tehri HPP- 1000 MW (4 X 250 MW)
Koteshwar HEP- 400 MW (4 X 100 MW)

2. What is the Design Energy or Annual Design Generation Capacity of Tehri HPP and Koteshwar HEP?

Design Energy means the quantum of energy, which can be generated in a 90 % dependable year with 95 % installed capacity of the hydro generating station.

Design Energy (Annual Design Generation Capacity) of Tehri HPP is 2797 MU and  Koteshwar HEP is 1155 MU. (Approved by CEA)

3. What is Plant Load Factor, Declared capacity, Infirm Power, Scheduled Energy, Scheduled Generation & UI charges?

Plant Load Factor or 'PLF' in relation to thermal generating station or unit for a given period means the total sent out energy corresponding to scheduled generation during the period, expressed as a percentage of sent out energy corresponding to installed capacity in that period, i.e  the ratio of the actual output of a power plant to its installed capacity less the Auxiliary Energy Consumption over a period of time.

Declared capacity (DC)-Hydro Power Generating Station

'Declared Capacity' or 'DC' in relation to a generating station means, the capability to deliver ex-bus electricity in MW declared by such generating station in relation to any time-block of the day as defined in the Grid Code or whole of the day, duly taking into account the availability of fuel or water, and subject to further qualification in the CERC regulations.

For run-of-river power stations with pondage, storage-type power stations and Pumped Storage Plants, Declared capacity (in ex-bus MW) for the day is which the station can deliver for at least three (3) hours, as certified by the nodal load dispatch centre after the day is over.

Infirm Power means electricity injected into grid, prior to the date of commercial operation of a unit of the generating station in accordance with Central Electricity Regulatory Commission.

Scheduled Energy (SE) means the quantum of energy scheduled by the concerned Load Despatch Centre to be injected into the grid by a generating station for a given time period.

Scheduled Generation (SG) at any time or for any period or time block means schedule of ex-bus generation in MW or MWh, given by the concerned Load Despatch Centre.

Unscheduled interchange (UI) Charges - All variations between actual net injection and scheduled net injection of energy for the generating stations and all variations between actual net drawl and scheduled net drawl of energy for the beneficiaries shall be treated as their respective Unscheduled Interchanges (UI), charges for which shall be governed by the relevant regulation specified by the Commission from time to time. Now, Unscheduled Interchange is termed as Deviation Settlement Mechanism and UI Charges as Deviation Settlement Mechanism charges.

4. What are the Auxiliary Consumption & Normative Auxiliary Consumption for Tehri HPP and Koteshwar HEP ?

'Auxiliary Energy Consumption' or 'AUX' in relation to a period, in case of a generating station means the quantum of energy consumed by Auxiliary equipment of the generating station, such as, the equipment being used for the purpose of operating plant and machinery including switchyard of the generating station and the transformer losses within the generating station, expressed as a percentage of the sum of gross energy generated at the generator terminals of all the units of the generating station. Provided that auxiliary energy consumption shall not include energy consumed for supply of power to housing colony and other facilities at the generating station and the power consumed for construction works at the generating station and integrated coal mine.

Normative auxiliary energy consumption for -

Tehri HPP = 1.2% of gross energy generation (Underground Power House)

Koteshwar HEP = 1% of gross energy generation (Surface Power House)

5. What is Plant Availability Factor and Normative Plant Availability Factor ?

Plant Availability Factor: Plant Availability Factor of a generating station for month/ year means the average of the daily Declared Capacities (DCs) available for all the days of month / year expressed as a percentage of the installed capacity in MW reduced by the normative auxiliary consumption.

Where, AUX = Normative auxiliary energy consumption in percentage

DC1 = Declared capacity (in ex-bus MW) for the ith day of the month which the station can deliver for at least three (3) hours, as certified by the nodal load dispatch centre after the day is over.

IC = Installed capacity (in MW) of the complete generating station

N = Number of days in the month / year

Normative Annual Plant Availability Factor (NAPAF): Normative Plant Availability Factor is basically PAF based on design energy considering all the constraints like maintenance of units, force outages & power potential at different reservoir levels etc.

Normative Annual Plant Availability Factor (NAPAF) for hydro generating stations shall be determined and approved by the Central Electricity Regulatory Commission (CERC).

6. What is the Normative Annual Plant Availability Factor of the Tehri HPP and Koteshwar Hydro Power Plant ?

Normative Plant Availability Factor of Tehri HPP (1000 MW) is 80% as approved in CERC Regulations, 2019 (earlier 77% from 1st April, 2009 to 31st March 2019).

Normative Plant Availability Factor of Koteshwar HEP (400 MW) is 68% as approved in CERC Regulations, 2019 (earlier 67% from 1st April, 2011 to 31st March 2019 ).

7. Is Tehri Hydro Power Plant running to its full capacity ?

Tehri HPP is running at its full capacity since commissioning of the plant. The energy generated from Tehri plant is 3146 MU, 3080 MU & 3177 MU for FY 2016-17, 2017-18 & 2018-19 respectively against design energy of 2797 MU.

8. Is THDCIL Only Hydro Power generating company or it has diversified to other power sector ?

THDCIL is not a Hydro Power generating company only. THDCIL has diversified to other power sectors also. THDCIL has installed two Wind power plants, namely; Patan Wind Power Plant (50 MW) and Devbhumi Dwarka Wind Power Plant (63 MW) in State of Gujarat. In Thermal Sector, 1320 MW Super Thermal Power Project in Khurja and in Solar Sector, 50 MW Solar Power Project in Kasargod, Kerala are under way.

9. Why the implementation of the Tehri Dam & HPP (1000 MW) has taken such a long period ?

The main reasons for delay in implementation of Tehri HPP are:

  1. THDCIL (Erstwhile Tehri Hydro Development Corporation Limited) took over the project from Uttar Pradesh Irrigation Department (UPID) in 1989. Before that, project was languishing due to shortage of funds with UPID, apart from other reasons.
  2. Opposition of Project by local people and Dharna by Sh. Sundar Lal Bahuguna on various occasions, after THDC took over and decided to start main works of project like Dam, Spillway, Power House etc.
  3. Govt. ban on shifting of population of Old Tehri Town till decision on Rehabilitation in May’1996.
  4. Review of technical aspects and other information relating to safety of Tehri Dam in June’1996.
  5. Delay in Rehabilitation and Resettlement of PAFs and Assets.
  6. Formation of New State (Uttarakhand).
  7. Review of Environmental and Rehabilitation aspects of Tehri Dam by Prof. Hanumantha Rao Committee during 1996-97.
  8. Review of Seismic Safety of Tehri Dam by the Committee headed by Dr. Murli Manohar Joshi constituted in April’2001 in light of:
    • Bhuj Earthquake.
    • Impact of Tehri Dam on self purification quality of Gangajal etc.
  9. Geological surprises faced in zone of water intake.
  10. Delay in achieving required MDDL due to stay by Hon’ble High Court in Aug’05 on PIL against closure of T2 Tunnel.

10. What are the benefits to Uttarakhand State from THDCIL ?

THDCIL has made maximum investment in State of Uttarakhand. Cumulative investment of approx. Rs.160 billion has been done by THDCIL in the Uttarakhand State till date. Further, investment of approx. Rs.90 billion is proposed for the upcoming new Projects in the near future.

THDCIL is also contributing to State Treasury through Taxes. In addition, expenditure of approx. Rs.16 Billion incurred on Rehabilitation of Tehri Project Affected Families and infrastructure facilities created at Rehabilitation sites has primed the local economy.

The Home State Uttarakhand is directly benefitted by the supply of 12% free power generated from THDCIL’s generating stations.M

The New Tehri Town has been developed as a modern hill station with all modern facilities for education (including an ITI and a University), Hospital, Financial Institutions, District Administration Offices, Markets, Bus Stand, and places of worship etc. This has led to enhancement of employment opportunities in commercial ventures like boating, transport, vehicle repair shops, business, hotel industries etc.

THDCIL has given direct employment to youth of Uttarakhand. The employment given by THDCIL is about 61 % from the Tehri District and about 125 persons from other Districts of Garhwal Region. Besides this, youth of Uttarakhand were provided necessary help and guidance for engagement in suitable self employment opportunities.

THDCIL is also concerned for upliftment of level of education in the state. THDCIL have opened Engineering College cum Hydro Power Institute namely, THDC Institute of Hydro Power Engineering and Technology in the vicinity of Tehri Project. THDCIL have also adopted two ITIs (ITI Chamba and ITI Gopeshwar). Besides this, THDCIL is also running schools in the vicinity of Project areas in Uttarakhand.

11. Why traffic is not being allowed over the Tehri dam top ?

Tehri dam is constructed with Earth and Rockfill material. A tunnel is passing 5 M below the dam top. To study the Dam behaviour, various types of sensitive instruments have been installed in it, on which adverse impact may occur due to heavy Vehicular traffic.  It is apprehended that vibrations / micro trimmers triggered by movement of vehicles could affect structural safety. Due to movement of public vehicles, there is a danger of occurrence of subsidence in its various parts and regions. The vehicular traffic is also not being allowed due to safety reasons. Superintendent of Police of Tehri during July’ 2012 had also communicated that in order to strengthen the Dam safety in view of terrorist activities, vehicular traffic may not be allowed over the Dam top.

Ministry of Power, Govt. of India, vide memorandum dated 21st June 2006, constituted 2 Expert Committees (related to Technical and safety aspects) for allowing movement over dam top. Ministry of Power, Govt. of India directed for compliance of suggestions given by expert committee & not to allow movement of commercial and personal vehicles over Tehri dam. Although, it was mentioned that villagers of nearby villages may be permitted for pedestrian movement over dam top after issuing passes by District Administration / Security Agency (CISF).

12. What is the risk of flooding in Rishikesh and Haridwar, when water from the Tehri Reservoir is released ? Or During rainy season, how Tehri Dam is helping the flood moderation ?

Flood moderation and regulation is one of the major benefits of Tehri Dam. During heavy rains Tehri Dam actually help people of Gangetic Plains, viz; Rishikesh, Haridwar and other downstream cities from the fury of floods by absorbing the flood water in its huge reservoir. With regulated flow from Tehri Project, it is ensured by the project authorities that the people in the down stream areas are saved from the heavy water flows in river Ganga, as happened in the past years 2010 & 2013.

Tehri Dam is a 260.5 M high Earth & Rock fill Dam. The dam has gross storage capacity of 3540 Million Cubic Meter (MCM) & live storage capacity of 2615 MCM between Minimum Draw Down Level (MDDL-El 740 M) and Full Reservoir Level (FRL-EL 830 M). The incoming flood water can be stored in the Reservoir during monsoon upto FRL. But, once the reservoir level reaches FRL, Spillways come into operation for releasing flood water. Tehri Spillways have been designed for a peak maximum flood (PMF) of 15,540 Cumecs, which has a probability of occurring in 1:10,000 years.

Tehri spillway comprises Chute spillways on Right Bank, 2 Nos. Right Bank shaft Spillways (RBSS) and 2 Nos. Left Bank shaft spillways (LBSS). The sequence of operation of spillways are as under

  1. As soon as the water level rises above 830 M, Chute Spillway would be brought into operation by stage-lifting all the three gates simultaneously.
  2. With full gate openings of the Chute Spillway, if the water level continues to rise above 830 M, the LBSS would be brought into operation by stage lifting of both the gates. The lifting of gates is similar to that of Chute Spillway gates.
  3. If with fully open gates of Chute Spillway and LBSS, the water level still continues to rise above 830 M, the un-gated RBSS, with intake at 830.20 M, shall automatically come into operation and discharge the excess flow.
  4. In the event of PMF of 15,540 Cumecs, 13043 Cumecs would be released through spillways as above and remaining water will be stored in the reservoir between FRL (830 M) & MWL (835 M).

Above mentioned sequence of spillways operation is based on conceptual approach of reservoir operation. But in practice, it is governed by reservoir rule curve and spillways can be operated even before achieving the FRL, if the situation arises due to higher inflows.

13. Tehri Dam has created Tehri Reservoir where the free flowing river Bhagirathi and Bhilangna have become stagnant. Does it not affect the quality of water ?

Though the water in the reservoir appears stagnant, but actually it is not. In order to assess the impact of Tehri Dam on the water quality of river Bhagirathi, water quality modeling study was also got carried out by the University of Roorkee. The study had concluded that there would be no adverse effect on the water quality due to impoundment. Dissolved Oxygen (DO) and Bio-Chemical Oxygen Demand (BOD) in the reservoir are expected to remain within permissible limits desired for drinking water source.

Central Water & Power Research Station (CWPRS), Pune, also carried out mathematical model study on water circulation and concluded that water in reservoir remains under dynamic circulation throughout the year and does not remain stagnant. Hence, though the water in reservoir may look static from outside, actually it is under dynamic circulation within the reservoir.

Regarding issue of self purification quality of Ganga (Bhagirathi) water, a study was carried out by National Environmental Engineering Research Institute (NEERI), Nagpur titled “SELF PURIFICATION QUALITY OF BHAGIRATHI / GANGA : IMPACT OF TEHRI DAM (2004)”. This study reveals that the uniqueness of river Bhagirathi / Ganga lies in the sediment content, which is more radioactive compared to other river and lake water sediments and can release Cu and Cr, which have bactericidal property and can harbour and cause proliferation (under static condition), that reduce and ultimately eliminate coli forms from the overlying water column. Thus, Tehri Dam is not likely to affect the quality or self preservation property of river Bhagirathi / Ganga, as it mimics a static container, which is conducive for conditions responsible to maintain the water quality.

Thus, it can be seen that enough precaution stands taken by project authorities in dealing with the concern and faith of people on water quality, after reservoir is formed. In all studies, it has been concluded that water quality remained same, as it was before formation of reservoir due to construction of Tehri Dam.

14. What benefits are given to the wards of Project Affected Families for admission in the THDC Institute of Hydro Power Engineering and Technology ?

5% seats are reserved in THDC Institute of Hydro Power Engineering and Technology for wards of Project Affected Families of Tehri Project.

15. Tehri Dam has helped in irrigation in the command area in Uttar Pradesh and providing drinking water to various town of Uttar Pradesh and also to Delhi. What are the benefits of the project to other states, where Ganga is flowing after U.P ?

Tehri Hydro Power Complex (2400 MW) a multipurpose project, was conceived & designed to store surplus water of the river Bhagirathi during monsoon and releasing stored water after monsoon as per the requirement of irrigation for UP and drinking purposes for UP & Delhi, besides giving peaking support to grid.

The electricity produced by Tehri Dam and HPP is provided to nine beneficiary states of Northern Region viz; Uttarakhand, Uttar Pradesh, Haryana, Himachal Pradesh, Delhi, Punjab, Union Territory of Jammu and Kashmir, Chandigarh and Rajasthan.

The water is stored in reservoir of Tehri Dam during Monsoon Season and is released round the year as per drinking & irrigation requirement which makes availability of water in Ganga throughout the year which may be utilised by other states for drinking, Irrigation and Commercial Purposes like Power Generation etc. where Ganga is flowing. Also, water availability is maintained round the clock at Haridwar / Rishikesh / Allahabad during important religious Snans. The main benefits due to availability of additional water from Tehri dam are :

  1. Irrigation in Command Area
    - Additional 2.70 Lac Ha
    - Stabilization 6.04 Lac Ha
  2. Drinking Water for Delhi (162 MGD) - 300 Cusecs (for 40 Lac population)
  3. Drinking Water for UP (108 MGD) - 200 Cusecs(for 30 Lac population)
  4. Annual Increase in generation of D/S projects - 200 MUs

16. Is it a fact that availability of water in Ganga is higher for Snans (Magh Mela, Kumbh mela etc) after the creation of Tehri Dam as compared to snans before construction ?

Yes, it is a fact. During Melas every year discharges form Tehri Dam augmented to facilitate Snans / rituals at Haridwar and places as far away as Allahabad and Varanasi. For example, availability of water was ensured by THDCIL for smooth snans during Maha Kumbh mela held at Haridwar in 2010 and Allahabad in 2013. Tehri Dam released 250 -300 Cumecs water from Tehri reservoir in order to ensure adequate water in Ganges for Kumbh mela snans, when water inflows in the Tehri reservoir were around 50-70 Cumecs. This was also appreciated by State Govt., Mela Authority & Sant Samaj.

17. How Tehri Dam has contributed to the economy at National and regional (Uttarakhand) level ?

Tehri Dam has been contributing in its own way, towards the growth of the economy at National and Regional (Uttarakhand) Level.

One percent increase in production of electricity in the nation contributes to 1% increase in GDP.

The electricity produced by Tehri HPP & Koteshwar HEP is provided to nine beneficiaries of Northern Region viz; Uttarakhand, Uttar Pradesh, Haryana, Himachal Pradesh, Delhi, Punjab, Union Territory of Jammu and Kashmir, Chandigarh and Rajasthan.

THDCIL is earning profit since first year of commercial operation of Tehri HPP, i.e; 2006-07. A part of the profits earned by THDCIL is paid back as dividend to shareholders, Govt of India and Govt of UP.

A part of the profit earned by THDCIL (2% of PAT) is earmarked for CSR and Sustainability activities in non-lapsable CSR and Sustainability fund.

12% of Power generated from Tehri HPP (1000 MW) and Koteshwar HEP (400 MW) is provided Free of cost to the Home State of Uttarakhand.

The company pays tax on purchase of goods and services, thus creates direct and indirect employment and stimulates the local economy.

Tehri Project will also play an important role for the development of surrounding areas & in improving the quality of life by providing employment opportunities and additional source of revenue in form of fishing, tourism, water sports etc., for which GoUK is taking initiatives.

18. What types of environmental mitigation measures have been taken during construction of the Tehri Hydro Power Project ?

Measures taken to mitigate adverse impact on environment during construction of Tehri Hydro Power Project are briefed below -

  1. Catchment Area Treatment (CAT) : Catchment Area Treatment (CAT) has been completed. Implementation of Action Plan by the Forest Deptt. of Govt. of Uttarakhand (earlier Government of U.P.) with funds provided by THDCIL, as per requirement. The area of 52,204 Ha. including 44157 Ha. of forest land and 8047 Ha. of agricultural land has been treated by state forest department.
  2. Preservation of Flora and Fauna : The studies were conducted through Botanical Survey of India (BSI) for flora and Zoological Survey of India (ZSI) for fauna affected due to reservoir. The reports were submitted to MoEF in 1993.For preservation of flora, a Botanical Garden located adjacent to the Reservoir with plantation of special species coming under submergence has been established in an area of 14.28 Ha. The Botanical Garden has been established to preserve important flora of the region. For this purpose, a high-tech nursery having plants of submerged area, is in operation. Botanical garden is being maintained by Sate Forest Deptt. through funding by THDCIL. As suggested by ZSI, a Mahseer Fish hatchery & fish farm site for induced artificial breeding of Mahseer fish, has been developed near Koteshwar Dam and currently handed over to state fishery Deptt.
  3. Water Quality Monitoring : In addition to the water quality studies done by IIT, Roorkee and NEERI, the water quality testing is being carried out regularly through CPRI, BHEL, Haridwar at the sampling locations Dharasu (river Bhagirathi), Ghansali (river Bhilangna), Zero point (D/s of Tehri Dam), U/s and D/s of Devprayag. No adverse effect on the water quality has been observed after impoundment of reservoir.
  4. d. Disaster Management Plan (DMP) : The Disaster Management Plan (DMP) prepared by THDC, was submitted in April 1992 to Ministry of Agriculture (MoA), the Nodal Ministry for this purpose. After deliberations, the Ministry of Agriculture (MoA) had, on 24.2.99, conveyed approval to the DMP.
  5. This Disaster Management Plan is regularly up-dated every year before monsoon and reviewed in coordination with Disaster Mitigation & Management Centre (DMMC), Govt. of Uttarakhand, Dehradun, which is the nodal agency for dealing disasters in the state of Uttarakhand.
  6. Compensatory Afforestation : The Catchment Area Treatment (CAT) Plan for Tehri Hydro Power Complex requiring compensatory afforestation has been completed on 4586 Ha. area of non-forest land (Lalitpur - 3960 H. & Jhansi - 626 Ha.). This includes compensatory afforestation against forest land of 338.932 Ha. affected due to Koteshwar HEP (400 MW). The plantation done on the non-forest land is being converted into protected forest by the State Forest Department. The compensatory afforestation against 1358.20 Ha. area of forest land acquired (at Virbhadra, Dehradun and Pathri in Haridwar) for rehabilitation of Tehri Dam PAFs, has been done on an area of 2716.40 Ha. of degraded forest land in Khanpur Forest Range in District Haridwar at the project cost.
  7. Command Area Development Plan (CADP) : The Command Area Development Plan (CADP) was submitted by the GoUP and was forwarded by Ministry of Power to MoEF in July 1998. CAD Plan also included areas, which now form part of Uttarakhand.

19. Has any study been conducted to evaluate the conditions/ status of project affected families of Tehri Dam Project ?, If yes, the details thereof.

To examine the effectiveness of R&R, a Socio Economic Study of the families rehabilitated, was conducted by the Administrative Staff College of India in March, 1993. The study broadly concluded that after rehabilitation, the Oustees have been provided with better facilities and amenities than they had at their earlier habitats. The value of assets and income generation from agriculture of Oustees has considerably increased. Their access to markets and wage earning opportunities also improved substantially. The annual income of households after rehabilitation has risen considerably. The new settlements are provided with Pucca buildings, electricity, drinking water facilities, good medical facilities, LPG connections etc.

The study was updated by ASCI, when R&R process was substantially completed, to compare the results of first study and to understand any changes. In its report of May, 2009, ASCI has concluded that “in the R&R for Tehri HEP, which was carried out on a massive scale, there is improvement in living standards of PAF’s when compared with the areas where they stayed earlier”.

20. What is the status of Rehabilitation of Tehri Project ?

The Rehabililation of Tehri project was implemented by the State Government of Uttarakhand with funds provided by THDCIL. The rehabilitation has been completed. Total 5291 Urban families and 5429 Rural Families were rehabilitatedwhereas 3810 partially affected families need not to be relocated.

In view of the representation received from the local inhabitants, Director (Rehab), GoUK decided to get the re-survey done by the Survey of India, so that the actual line could be drawn at RL 835 M.On the advice of Director (Rehab), Survey of India conducted the survey and fixed a new demarcation line of RL 835 M. Due to error in earlier demarcation of survey line at RL 835 M, some more land was to be acquired in 45 villages (already included in 109 villages) and additional 108 eligible families were rehabilitated as per demarcation of new survey line of RL 835 M.

The rehabilitation of all identified families upto EL 835 M was completed as per the R&R policy. For rehabilitation of additional 108 families due to fresh survey of Full Reservoir line, the State Govt. has confirmed that land upto RL 835 M had already been acquired and all affected families, which were found eligible, have been rehabilitated. Cost of Rehabilitation and Resettlement was Rs. 1380.96 Cr. As decided in Meeting held between Government of India, Government of Uttarakhand and THDCIL under Chairmanship of Secretary (Power), Govt. of India on 30.06.2011, THDCIL released Rs.102.99 Cr. against full and final settlement for completion of R&R works of Tehri Project.

The total expenditure incurred on R&R is Rs.1484 Cr.

21. Are people affected by Tehri Project still having some grievances and what is the mechanism to settle the grievances ?

There are some grievances from Project Affected Families. In order to listen and examine the grievances from Project Affected Families a Grievance Redressal Cell is in place. In compliance of the orders of the Hon’ble Supreme Court, the Registrar General, Uttarakhnad High Court appointed a Retired District Judge (Additional) to look into the grievances of the PAFs relating to compensations, allotment etc.

22. Is CSR and Rehabilitation & Resettlement same?

No, CSR and Rehabilitation and Resettlement are not same.

R&R is applicable to project affected families, who have to be compensated for the impact of project on their land / property / livelihood. They were listed at the project preparation stage itself, and are covered for R&R, as part of the project cost.

CSR is Corporate Social Responsibility, under which the business focuses on triple bottom line concept, i.e; people, planet and profit. The expenditure under CSR is out of the profit of the business of THDCIL. As per the current Government Guidelines, following range is fixed for CSR and Sustainability.

PAT of CPSE
(in previous year)		Range of Budgetary allocation for CSR and Sustainability activities
(as % of PAT in previous year)
i.Less than Rs.100 Cr.3% - 5%
ii. Rs.100 Cr. to Rs.500 Cr.2% - 3%
iii. Rs. 500 Cr. and above1% - 2%

THDCIL has been actively involved in CSR activities in the areas of education, health, skill development, income generation schemes, infrastructure support and environment protection.

For more details on CSR, please refer the link CSR on Website.

23. Does THDCIL have any Joint Ventures(JVs)?

With the focus on clean and green energy, a JV Company named ‘TUSCO Ltd.’ between THDCIL and ‘UPNEDA’ (Uttar Pradesh New and Renewable Energy Development Agency) has been incorporated in Sep’2020 for development of 2000 MW Ultra Mega Solar Power Parks in the State of U.P.

Subsequently, another JV Company named ‘TREDCO Rajasthan Ltd.’ between THDCIL and ‘RRECL’ (Rajasthan Renewable Energy Corporation Limited) has also been incorporated in Mar’2023 for development of 10,000 MW Ultra Mega Renewable Energy Parks in the Rajasthan state.

A JV Company named, THDCIL-UJVNL Energy Company Limited (TUECO Ltd) between THDCIL and ‘UJVNL’ (Uttarakhand Jal Vidyut Nigam Ltd.) has been established in Dec’2023 for development of Hydro Power Projects in Uttarakhand.

24. What is Pumped Storage Plant (PSP)?

A Pumped Storage Plant (PSP) is a type of hydroelectric power plant used for energy storage. It operates by pumping water from a lower reservoir to a higher reservoir during periods of low electricity demand i.e off-peak hours (typically at night or when excess electricity is available) using surplus energy from other power sources. Then, during periods of high demand i.e peak hours, the stored water is used to generate electricity and the water is released back into the lower reservoir, passing through the turbines. PSPs play a crucial role in balancing the supply and demand of electricity in the grid, providing a means to store energy when it is abundant and release it when needed. This helps to stabilize the grid and ensure a reliable electricity supply.

25. How the Tehri hydro projects are beneficial in terms of Flood Control, Irrigation and Drinking Water Supply etc.

Flood Prevention: One of the important role of Tehri dam is to store flood water and safeguarding the downstream population from its devastating effect. Tehri dam, even in the worst scenario (1 in 10,000 years return period flood) is capable to store the peak of flood and thereafter passing the same to the river in downstream in a regulated manner when the flood recedes mitigating the impact of flood. Tehri dam has played a crucial role in averting the flood of higher order in the river Ganga and mitigated havoc by storing high flood inflows of river Bhagirathi and Bhilangana in the year 2010 & 2011. During the floods of Jun’2013 when Kedarnath tragedy happened in Uttarkhand, almost complete discharge of river Bhagirathi was stored in Tehri dam avoiding the disaster upto Rishikesh/Haridwar.

Irrigation and Drinking: Water stored in the Tehri dam irrigates about 2.70 Lac hectares and stabilization of about 6.04 Lac hectares of land in the Gangetic plains of Uttarakhand and Uttar Pradesh apart from providing 300 cusecs and 200 cusecs of water for drinking purposes to Delhi and UP respectively. As an estimate, it fulfils the drinking water requirement of 40 Lac population in Delhi and 30 Lac in UP. During lean period, when inflow of river Bhagirathi at Tehri becomes very low and irrigation through canals in UP state becomes heavily dependent on discharge, the required water is released from Tehri Dam.

Last Updated on 19/7/2024