Teesta III Hydro Project Running Energy Loss & Harming Environment

Teesta III hydro power project suffered an energy loss of over 1450 million units between June-September 2017.

6 min read
Teesta stage III hydro power project suffered an energy loss of over 1450 million units.

Reports of the Ministry of Power (MOP) and the Central Electricity Authority (CEA) indicate that the 1200 MW Teesta stage III hydro power project suffered an energy loss of over 1450 million units during the period June-September 2017. The loss is accountable to the non-completion of the 400 kv dc transmission line of Teesta III from Sikkim to Kishanganj Bihar.

The mega hydro project was officially commissioned in February 2017.

But due to the non-completion of the transmission line, the daily loss of peaking power is as high as 200-300 MW. Loss of peaking power and generation in non-peak periods is in non-compliance of CEA directions and MOP policy to shift from base load to peaking for hydro stations, informed VK Gupta, spokesperson for the All India Power Engineers’ Federation (AIPEF)

It was also observed that in addition to 400-500 MW spillage loss at Teesta III due to transmission constraints, the Rangpo Siliguri line operating at high loading was incurring power loss of the order of 40 MW during the June-September 2017 period.

24x7 Loss For Not Being Able to Construct the Kishanganj Line

In a letter to the Power Minister dated 19 December 2017, the AIPEF outlined the environmental consequences of spillage loss at Teesta III project in detail.

Due to non-completion of 400 kV line to Kishanganj, the entire power of Teesta III was being injected at Rangpo (instead of Kishanganj), and since the double circuit line from Rangpo to Siliguri (Binaguri) had a twin Moose conductor (as against the quad moose conductor of Kishanganj line) the loading of Rangpo Binaguri line was restricted – this caused the backing down of Teesta III generation to about 900 MW, as against a station capacity of 1320 MW.

On the other hand, the water flow of the Teesta was enough to generate 1320 MW round the clock during high flow period of the 2017 monsoon from June to September. So for four months, there was continuous 24x7 loss of about 400-500 MW at Teesta III because of power evacuation constraints caused by failure of TUL to construct the Kishanganj line, the letter details.

To assess the quantum of energy loss, the data for the period June to September 2017 – including energy sent out ex bus from Teesta III in MU (million units) – was measured as metered by Special Energy Meters (SEM). The data also includes gross generation at Teesta III as per the CEA, energy scheduled as per the Eastern Regional Load Dispatch Centre (ERLDC) ,energy potential possible under high flow conditions – assuming station were to run at 100%  capacity of 1320 MW (including 10% continuous overload margin as per specifications). The energy loss calculation also took into account
auxiliary consumption @ 1.2%.

Teesta III Hydro Project Running Energy Loss & Harming Environment

Loss in the First Year of Project Due to Spillage and Energy Loss

Teesta III Hydro Project Running Energy Loss & Harming Environment
(Photo Courtesy: Teesta Urja Limited and Power Grid Corporation India Limited)

If the 400 kV line to Kishanganj had been commissioned, with full inflow available in Teesta, the Teesta III HEP had the potential to generate 3818.6 MU (ex bus) against which the actual energy sent out (ex bus) was only 2356.42 MU – that indicates an energy loss of 1462 MU.

TUL have indicated an energy rate of INR 5 per unit for Teesta III in the ERPC meeting of 13 June 2017. Thus, an energy loss of 1462 MU translates to a financial loss of INR 731 crore due to delay in construction of the transmission line to Kishanganj.

The original estimated cost of the Teesta III to Kishanganj transmission line was INR 770.8 crore, while the loss due to delay in the very first year is INR 731 crore, due to spillage and energy loss, AIPEF letter mentions.

The cost of Teesta III-Kishanganj transmission line was initially pegged at the price levels of August 2008 at INR 770.80 crore with a commissioning schedule of 36 months from the date of Financial Closure and at a debt equity ratio of 75:25.

Spillage Affected Environment

Teesta River.
Teesta River.
(Photo Courtesy: Teesta Urja Limited and Power Grid Corporation India Limited)

A joint venture was formed between Teesta Urja Limited and Power Grid Corporation of India Limited in a 75:25 ratio. The new subsidiary company – Teesta Valley Power Transmission company Limited (TVPTL) – was responsible for execution of the transmission line from Teesta III up to Kishanganj.

However, due to delays in the project, the final revised cost estimate was put at INR 1450.36 crore, as of 5 January 2016, with the revised scheduled commercial operation date fixed at 31 March 2017.

The spillage of water, resulting in energy loss of 1462 MU (June-September 2017) also had an environmental impact, asserted AIPEF. They argued that if the Kishanganj line had been completed before June 2017, it would have resulted in extra hydro energy generation of 1462 MU, which would have displaced thermal energy of an equivalent quantum, and saved the equivalent amount of coal-fired energy.

“As 1 kWh of coal-fired energy results in 1 kg of carbon dioxide, the conclusion is that energy loss of 1462 MU at Teesta III has resulted in the release of 1.46 million tonnes of additional carbon dioxide during the period June to September 2017,” argued Padamjit Singh, chief patron of the AIPEF. It may not be out of place to point out here that in the CDM registration for CER points as claimed under UNFCCC norms, Teesta Urja has had adverse comments.

The AIPEF, vide a letter dated 19 December 2017, pointed out that the line portion between Teesta III to Rangpo had one circuit direct and operational. The second circuit between Teesta III to Rangpo is Loop in-Loop Out (LILO) at Dikchu. The portion between Dikchu and Teesta III is operational, but the portion between Dikchu to Rangpo is idle and has been non-operational since January 2017 because of ROW problems and reduced clearance, the AIPEF letter stated.

“CEA report does not mention a target date for the Dikchu-Rangpo section lying idle since January 2017,” said Gupta. “This not only reduces the reliability, it also results in double line loss and also implies that capital investment on one circuit between Dikchu and Rangpo has remained idle for 11 months,” AIPEF spokesperson Gupta added.

The official records of TVPTL indicate that the Teesta III-Rangpo CKT II line (priority segment) and the Teesta III-Dikchu lines have been in commercial operation from 16 January 2017 and 13 April 2017 respectively.

For successful declaration of COD, all the required auxiliary systems in a power station have to be commissioned along with the main plant viz generators, transformers and turbines. With the same logic, the 400 kV transmission lines that have to evacuate the power generated had to be commissioned simultaneously with power to the station or in advance.

Earlier in June 2017, the project was slammed as a failed example of public-private partnership since it was selling electricity at a discounted rate in the open market, as against the contracted rate by the AIPEF.

The Federation claimed that power produced from the Teesta III power plant was being sold at a rate below Rs 3 per unit in the open market by the PTC (Power Trading Corporation) due to surplus market conditions, after Punjab, Haryana, Rajasthan and Uttar Pradesh refused to buy electricity from it at Rs 6 per unit instead of the original Rs 1.92 paise per unit contracted rate. The entire power from the project was to be purchased by the Power Trading Corporation (PTC), which in turn signed contracts to sell 70 percent power to Punjab (340 MW), Haryana (200 MW), UP (200 MW) and Rajasthan (100 MW).

(The author is a Gangtok-based journalist.)

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