Cost surge clouds Tk870cr Kaptai hydropower revamp

The Bangladesh Power Development Board (BPDB) has proposed spending nearly Tk870 crore to rehabilitate two ageing units of the country's only hydropower station in Kaptai, aiming to restore up to 30 megawatts (MW) of lost generation capacity and extend their operational life by 20 years.

However, the proposal has come under scrutiny from the Planning Commission over its sharply increased cost, repeated tender failures and the absence of a clear assessment of the causes of equipment damage.

The project covers Units 4 and 5 of the Karnafuli Hydropower Station in Rangamati, each with an installed capacity of 50MW but currently generating only 35�"40MW. The combined generation shortfall is estimated at 20�"30MW.

The three-year project, scheduled for January 2027 to December 2029, involves replacing damaged turbine and generator components, modernising control systems and upgrading electrical and safety equipment.

The Planning Commission's Industry and Energy Division reviewed the proposal at a meeting in mid-October chaired by its former member Nurunnahar Chowdhury.

The project aims to restore 20–30MW and extend its lifespan by 20 years

“The need for rehabilitation is underscored by the condition of the two units, which were commissioned in 1988 and have operated for about 37 years,” Nurunnahar said.

According to a BPDB feasibility study, cracks have developed in seven of the 10 rotor-rim supporting ledges in Unit 5 and six of the 10 in Unit 4, with the former in a more critical condition.

Repeated welding repairs have hardened the affected metal, making it brittle and increasing the risk of major mechanical failure and potentially irreversible damage.

The study attributed the deterioration to excessive turbine vibration and age-related deformation of the foundations, which distorted the stators and created imbalanced magnetic forces. The units were last rehabilitated in 2010-11, although manufacturers recommend major overhauls every eight to 10 years. Their control and protection systems have also become obsolete, while spare parts are increasingly difficult to obtain, making further piecemeal repairs unsustainable.

Under the proposed rehabilitation, the BPDB would replace major generator components, including stator coils, rotor poles, spokes and rim-support systems, as well as turbine runners, discharge rings and bearings. Digital governors, modern control systems and static excitation equipment would also be installed.

The work would additionally cover the 132-kilovolt and 11-kilovolt switchyards, transformers, cooling systems and firefighting facilities. No additional land would be required.

Of the estimated Tk869.97 crore project cost, Tk656.99 crore would come from a project loan, Tk200.58 crore from the government and Tk12.41 crore from the BPDB's own resources.

The turnkey supply and works package accounts for Tk647.85 crore, including Tk221.97 crore for hydraulic turbines and Tk205.17 crore for generator and excitation systems. Customs duties, taxes and VAT are estimated at Tk148.47 crore.

The Planning Commission has also questioned the BPDB's procurement record, following several unsuccessful attempts to appoint a contractor between 2018 and 2022.

Toshiba declined to act as the prime contractor in 2019, prompting the BPDB to invite international tenders. 

The first tender attracted only one bidder and was cancelled. A second tender in May 2021 also received a single proposal, with the evaluation committee finding that a restrictive technical condition had limited competition.