Author: Jigme Tenzin

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Hydrogen workshop

DGPC organised a workshop on hydrogen from September 27 to 28, 2022. The workshop presented the findings from an “exploratory study for the conversion of electricity to hydrogen fuel and/or other energy storage systems in Bhutan” carried out in 2021 in collaboration with FVT and group, Austria, as the consultants.

The workshop further discussed considerations of the possible pathways for hydrogen project implementation in Bhutan and provide recommendations for the way forward. It was aimed at knowledge transfer and to gain a good understanding of the green hydrogen technology and what it may hold for Bhutan in the future.

Representatives from BEA, BHUTAN AUTOMATION, BPC, DHI, RSSTEM, MoEA, and MoIC, in addition to participants from DGPC attended the workshop. Executives and senior officials from relevant agencies attended the inaugural session.

Bhutan embarks on small hydropower projects for energy security

… Bhutan imported over 240MU of energy from India between January and March 16

Kuensel | Dechen Dolkar | July 9, 2022

The Druk Green Power Corporation (DGPC) will begin construction of three small hydropower projects, one each at Lhuentse, Zhemgang and Haa, with a total generation capacity of 104 megawatts (MW).

Prime Minister Dr Lotay Tshering attended the Salang Tendrel ceremony at the Powerhouse of the 32MW Yungichhu hydropower project in Maetsho gewog, Lhuentse, yesterday.

Lyonchhen said, “His Majesty said that Bhutan cannot afford to go back to the pre-pandemic status. When the nation was going through the Covid-19 restrictions, and when people stayed indoors, we’ve been working on many plans and programs to take our nation to an all new level. One such is the Small Hydropower Projects. The day is finally here. I feel we’ve taken a humble step towards fulfilling His Majesty’s vision for the country.”

He said that is why it was a historic day and at the same time, a matter of pride for Bhutan. “This is a step towards ensuring energy security and boost economic activities that will help us generations.”

For the first time, he said, only Bhutanese companies and individuals are being involved at all layers of the hydropower project. “We now have all the expertise in house. With the wealth of experience we have accrued over the decades, one that matches out geographical terrain, geological demands and all other factors, we have the best expertise now.”

He said that Bhutan could not have chosen a better timing to invest in local expertise, machineries, workforce and the economy. “To invest in our economy as we aspire for a new normal for Bhutan, we cannot think of any better return on investment than this.”

“I also thank the government of India for all the assistance and partnership in Bhutan’s hydropower journey for decades. As we continue to work together, it’s also thanks to them that we today have the confidence to take up the small projects ourselves. We’ll keep striving to do more and bigger projects,” he said.

While the project in itself is of huge excitement for Bhutan, overall, this is a part of major transformation that is going on in almost every pertinent sectors. “Therefore, the excitement was amplified even more,” Lyonchhen said.

Lhuentse officiating dzongdag, Wangchen Norbu, said that the project would immensely benefit the communities.

He said that it will also bring about infrastructure development. The farm road will be widened and blacktopped.

“The communities will be able to market their farm and dairy produce which they were not able to market till now,” the officiating dzongdag said.

Wangchen Norbu said it will also create employment opportunities and boost the economy in the community.

Maedtso Gup, Gembo said that since it’s a remote village and the villagers are unable to sell farm produce, communities are hoping that they can make a good income from selling them to workers.

He said that it will also offer employment opportunities in the community. There are few school dropouts who were not able to get employment.

He also said that there are few shopkeepers and they will also be benefited immensely.

The idea of building numerous small hydro projects across the country was initiated by the government when the country was experiencing major economic difficulties due to the pandemic. The implementation of the projects will occur in a phased manner.

Phase One

The first phase of the small hydropower projects will also include the construction of the 54MW Burgangchhu in Nangkor gewog, Zhemgang and 18MW Suchhu in Sangbaykha gewog, Haa.

Currently, roads to the powerhouse and intake locations at these two sites are being constructed.

The three projects will generate about 494 million units (MU) of energy annually. They are estimated to cost around Nu 9.2B when completed in 2025.

Between January 1 and March 16 this year, Bhutan imported a little over 240MU of electricity from India through the energy exchange at a cost of Nu 798M.

Located in some of the most remote areas of the country, these small hydropower projects are expected to help accelerate post-pandemic economy recovery, generate employment and bring tangible economic benefits to the people at the grassroots level.

With an aggregated installed capacity of 104MW, the three projects will contribute to strengthening overall energy security and improving grid stability in the country, a press release from DGPC stated.

The DGPC conducted the feasibility studies and developed the Detailed Project Reports (DPR). Druk Hydro Energy Limited, a wholly-owned subsidiary company of DGPC, will oversee the implementation of the projects.

The construction works at all three sites will be undertaken by Bhutanese contractors. The small power plants will be fully automated using the latest state-of-the-art technology to ensure an uninterrupted power supply and low operations and maintenance costs.

The three power projects are expected to employ at least a thousand Bhutanese youth during the construction phase including a hundred de-suups who will be deployed through the DeSuung National Service for Hydropower Construction at the Yungichhu site.

DGPC Managing Director, Dasho Chhewang Rinzin, said that in cognizance of the growing need and priority for enhancing domestic energy security, stimulating economic growth, and in developing local capacity, DGPC was entrusted by the government to assess the potential for small hydropower projects across the country and initiate the construction of those more techno-economically viable projects.

Starting at the beginning of 2021, DGPC undertook extensive studies through several stages of desktop, reconnaissance, field investigations, preliminary designs, and feasibility studies to select the most techno-economically viable projects from an initial list of about 190 sites with a focus on grassroots-level social engagement and long-term environmental sustenance.

He said that through these extensive studies, three projects out of 190 sites were eventually selected for feasibility studies under Phase I small hydro projects.

The feasibility studies, which were completed in December 2021, determined that these three projects were techno-economically feasible to be taken up for construction.

The civil works for the Yungichhu hydropower project were awarded to Rigsar Private Construction Private Limited on June 8 at a contract amount of Nu 1.38 billion with a construction duration of 31 months.

The overall cost of the project is Nu 3.66B (excluding IDC and price variation) and the implementation duration is 36 months. The levelized tariff for the Yunichhu project works out to around Nu 4.52 Nu/kWh. After commissioning, the project will generate 158MU of energy.

The civil works for the Burgangchhu project were awarded to Construction Development Corporation Limited (CDCL) at Nu 0.992B.

The project will generate around 260MU of energy. The total cost of the project is Nu 3.56B

The civil works for Suchhu project were awarded to Vajra Builders Private Limited, at a contract cost of Nu 1.004B

The project will generate 77MU of energy. The total cost of the project is Nu 2.09B.

According to the DGPC, electro-mechanical equipment will be sourced from reputed and established international companies that have the capacity to provide state-of-the-art technologies to enable the fully automated operation of the power plants.

The hydro-mechanical works (gates and hoists) will be directly awarded to Bhutan Hydropower Services Limited (BHSL) to be designed and engineered in close coordination with Bhutan Automation Engineering Limited, who will also be implementing the SCADA system. The pressure penstocks will be awarded through limited bidding.

Phase II projects

The DGPC is currently conducting feasibility studies for the four potential projects to be undertaken in the second phase of small hydropower project construction. With cumulative experience and advanced technical expertise, the company looks forward to undertaking higher capacity projects including small reservoir plants.

Five other projects with a total installed capacity of 261MW have been shortlisted for feasibility studies under Phase II of the small hydropower projects.

It includes 85MW Jomori under Jomotshangkha, Samdrup Jongkhar; 45MW Gamri-I, 85MW Gamri-II projects under Sakteng, Trashigang; 18MW Druk Bindu-I and 8MW Druk Bindu-II projects under Tendruk, Samtse; and 20MW Begana integrated water project under Kawang, Thimphu.

The feasibility studies for the 85MW Jomori hydropower project will be completed by December 2022 while the DPR updates and feasibility studies of the other Phase II projects are scheduled to be completed by June 2023.

“The constructions of the techno-economically viable projects under Phase II are expected to be started within 2023,” Dasho said.

The DGPC MD said that under Phase-III of the small hydro projects, it is intended to expand the scope to a small reservoir scheme of maybe 200MW, and from there move on to larger hydropower projects.

Bhutan has an estimated techno-economically feasible hydropower potential of about 33,000 MW of which only about 7 percent is being harnessed with the present installed capacity of 2,326 MW from its seven large operating power plants.

The country today exports about 70 percent of the generated electricity to India after meeting its internal demand.

Tala powerplant resumes generation

Kuensel | Dechen Dolkar | March 19, 2022

Tala powerplant restarted generating electricity on March 17 after completing major repairs to the 23km headrace tunnel (HRT) and other works.

The Tala powerhouse was shutdown on January 1 for inspection and rectification of the HRT and it was expected to restart operation on March 28.

Druk Green Power Corporation (DGPC) Managing Director, Dasho Chhewang Rinzin, said that a team of over 220 officers and support staff worked round the clock and the inspection and rectification works completed by the first week of March.

Issues and findings

DGPC MD said that there were voids and cracks in the sections of the tunnels and the debris on the tunnel floor. The robotic underwater inspection in March 2021 had shown the problems.

In the Padechhu area between Takti and Gedu, the damages to the tunnel were more severe. It was confirmed this section of the tunnel passed through poor geology. Even during construction, the then Tala project authority had faced difficulties in completing this section of the tunnel.

“It was timely that the inspection was undertaken,” the MD said.

Every meter of the tunnel was inspected and the findings were verified by an expert committee who also recommended the remedial measures. They were further reviewed by an international consultant online.

The rectification works involved chipping of the damaged sections of the tunnel and undertaking remedial measures like adding reinforcement and anchor bars, placement of high-performance concrete, chemical treatment and grouting based on site conditions and extent of damages.

The appearance of concrete debris at the generating units cannot be ruled out as several lengthy sections of the tunnel run through ‘very poor geological conditions’.

Even if there are no concrete debris at the generating units, periodical inspection of the tunnel should be done, he said.

The final cost of the exercise is about Nu 115M.

Of that, Nu 75M was to buy specialised construction equipment, which can be used in either maintenance of the existing power plants or transferred to projects under construction.

“Druk Holding and Investments and the DGPC board had given special dispensation for the procurement of specialised construction equipment and materials,” he said.

DGPC prioritised and mobilised workers from Tala hydropower plant and other power plants and its subsidiary companies. Expertise, manpower, materials and equipment support also came from underconstruction hydropower projects especially Punatsangchhu II and Nikachhu projects.

He said the Covid-19 task forces facilitated movement of workers and construction equipment. BPC and BT helped with the construction power and communication networking inside the tunnel.

“Experts visited the different sites in bubble mode while expert advice was availed through video linkages,” he said.

Import of electricity suspended

With Tala plant resuming power generation, import of electricity from India was immediately stopped. Bhutan would now be generating surplus power for export to India.

Dasho Chhewang Rinzin said, “However, the arrangement for imports from India will be kept as an option, in case of exigencies.

Starting January 1, 2022 to March 16, Bhutan imported a little over 240 million units of electricity from India through the energy exchange at a cost of Nu 798M.

Barrage construction at P1 could take four years

Kuensel | Phurpa Lhamo | November 19, 2021

Once confirmed, the construction of a barrage to replace the dam at Punatsangchhu Hydroelectric Project I (PI) will take at least four years to complete.

Dam construction has been stalled for a while now, and an independent study has shown that a barrage is feasible around 2.5km upstream.

According to the Druk Green Power Corporation (DGPC) managing director (MD), Dasho Chhewang Rinzin, if a decision is made in 2022 to proceed with the barrage option, the PI project could be operational by early 2026.

“The construction of a barrage with the tunnel joining the barrage to the already built usable component of the dam could take up to four years from the start date,” he said.

The DGPC is currently providing support and backup to an international hydropower consultancy group ‘Stucky’ to prepare a detailed project report (DPR) on the construction of a barrage.

In July of this year, Minister of Economic Affairs Loknath Sharma said that the government had conveyed to the Indian government that a barrage could replace the dam at PI.

The decision to construct the barrage came after the right bank of the dam experienced multiple landslides. The project witnessed its first slide in July 2013, followed by a slide in August 2016, and later again in January 2019.

In 2013, the project’s consultant, the Centre Water Commission (CWC) of India, submitted a holistic report on the dam. The CWC filed its report on strengthening measures in October 2019.

The CWC stated that the safety factor was 1.2 to 1.4.

The National Hydroelectric Power Corporation (NHPC) reviewed the report and had differing views on the report. The NHPC has pointed out flaws in the design, stating that the safety factor was insufficient.

The NHPC vetted the report and disagreed with it, because the corporation’s estimate showed a safety factor below 1.

According to international standards, for a dam to be built, the safety factor should be at least one.

The issue remained unresolved, so the government initiated an independent review, which is currently led by the DGPC.

While the DPR for the barrage was to be submitted in June 2021, the submission of the DPR has been postponed to February 2022.

Dasho Chhewang Rinzin said that while the preliminary design report submitted in March 2021 confirmed that a barrage was feasible, Stucky recommended further detailed geophysical and geotechnical investigations for design and cost optimisation through specialised agencies, especially covering the barrage footprint project components.

“Since many of these additional geotechnical investigations could not be taken up during the 2021 monsoon months due to the very high river discharge, the submission of the DPR had to be postponed to February 2022,” he said.

What is a barrage?

According to Dasho Chhewang Rinzin, a barrage is similar to a dam of lower height and, therefore, meant fewer demands in terms of the technical requirements for founding on the riverbeds.

He said that a barrage acts like a dam to divert the water from the river into the tunnels, but without the storage capacity. “Therefore, in a very true sense, the barrage is a pure run-of-the-river scheme and would generate power in keeping with the actual river discharge. Under exigencies, some of the water available for generation may have to be spilled in the winter months. With the planned barrage, the project would lose its flexibility for daily peaking generation.”

The dam meant a storage capacity that would give the project several hours of daily peaking generation capability in the winter months.

The dam also ensured flexibility in operating the powerhouse, which would have ensured that spillage of water during exigencies in the winter months was limited.

Kuensel learned that as of December last year, Nu 28 billion (B) has been spent on dam construction.

It was also learnt that the estimated cost for a barrage construction is Nu 16B. However, around Nu 4.9B worth of the assets created under the dam package could be utilised. The structures include desilting chambers and the connecting head-race tunnel, but the dam pit area will have to be abandoned.

While it has been speculated that the power generation will decrease with the construction of the barrage, Dasho Chhewang Rinzin said that all hydropower projects in Bhutan that have been built or that are under construction are considered as run-of-the-river schemes with some limited storage capacity for daily peaking in the winter months.

“With the adoption of the barrage option, due to non-availability of the flexibility of operation during the lean discharge months, the loss in generation due to exigencies when there could be spillage of water is estimated at about a maximum of 1 percent of the total estimated design annual generation of 5,544MU,” he said.

He stressed that while an impact on generation is expected with the barrage option, the decrease in power generation will be minimal.

Meanwhile, additional specialised geotechnical investigations are also ongoing.

Dasho Chhewang Rinzin said the specialised core drilling, including cone penetration tests and cross-hole topography, have started after the contractor mobilised from India and the work is expected to be completed by December of this year.

“The input from these investigations will be critical in arriving at the most optimised design and cost solution for the barrage option,” he said.

PII needs 2,000 workers to meet July 2023 deadline

Kuensel | Phurpa Lhamo | November 13, 2021

Due to pandemic-related travel restrictions and stringent Covid-19 protocols, Punatsangchu Hydropower Project-II (PII) currently has a shortage of about 2,000 workers at the site.

There are currently 1,440 Indian and 522 Bhutanese workers with the project.

According to the PII managing director, NC Bansal, due to a shortage of manpower, some of the non-critical aspects have been halted. “The immediate requirement of the project is the introduction of required manpower. All possible efforts are being made, observing all required protocols towards Covid-19 pandemic.”

He said nearly 2,000 workers are required as of now to take up working on the available work fronts.

When the pandemic hit in August last year, Indian workers expressed their wish to leave to their homeland India with the announcement of the lockdown and border gates at risk of closing.

Following the exodus of expatriate workers, the management announced vacancies for Bhutanese.

Starting in October 2020, more than 400 Bhutanese were recruited in small batches. Indian workers were also simultaneously inducted.

Officials said 1,370 Indian workers have been inducted for the project as of yesterday.

NC Bansal said that following the mass recruitment in 2020, many Bhutanese workers have left the project. “Nearly 500 Bhutanese workers have left.”

However, Bhutanese workers continue to show their disappointment over the management and the Ministry of Economic Affair’s failure to provide incentives.

According to a former PII worker, after joining in November of last year, he received incentives for three months, in January, February, and March.

He said that he left in April, for which he hadn’t received the incentive of Nu 4,000.

The construction company, Jaiprakash Associates Limited (Jaypee Group), provided the individuals with more than Nu 13,000 every month.

“Many joined to get the incentive and the salary. The work is risky, too,” the worker said.

NC Bansal agreed that the incentives were provided up to March 31 this year. “Now the Department of Labour is considering additional funding.”

Meanwhile, project officials claimed that 90.91 percent of the work has been completed as of October.

“The majority of the work related to the dam, desilting chambers, headrace tunnel, surge shaft, butterfly valve, and tailrace tunnel have been completed; work related to application of concrete in the powerhouse and assembly of the generating plant and equipment are under progress with the limited manpower available at the site,” NC Bansal said. “The project is expected to reach completion by July 2023 on a best-efforts basis.”

BHSL manufactures turbines

Kuensel | Nima | September 23, 2021

Bhutan Hydropower Service Limited (BHSL) in Jigmeling, Sarpang has started manufacturing runners (turbines) for the hydropower plants in the country and also for the hydropower projects in India and Turkey.

The hydropower service centre is currently manufacturing two Pelton runners for the Tala hydropower plant, of which one would be ready by the end of this year. It takes almost one year to manufacture a turbines.

BHSL manufactured two different types of turbines to date.

Hydropower projects in the country imported hydro-mechanical equipment in the past incurring huge transportation and other costs.

Construction of hydropower projects is expected to be faster with BHSL having a fully equipped manufacturing plant, manned by local engineers and experts.

Interim CEO of the company, Pelden Drukpa, said that manufacturing of runners started in 2018 and dispatched a turbine for Basochhu hydropower plant in Wangdue in 2020.

“In the past, all these services were imported. We’re happy that we can do it ourselves now. We’re retaining money within the country,” he said.

He added that the equipment would be cheaper and of better quality, as the machines of the plant are operated by Computerised Numerical Control (CNC) system – a computerised manufacturing process.

A cost of one turbine comes around Nu 100 million.

“We also have skilled manpower and welders qualified for all levels. The hydro components would be cheaper and supplied on time which would not affect the hydropower generation of the plants. We’re also able to build competency,” said Pelden Drukpa.

BHSL initially sought expertise from GE, one of its shareholders, in manufacturing the runners. Today, the company has its own team managing the plant.

BHSL started manufacturing runners for hydropower plants, four years after its establishment in 2014. The hydropower service centre also plans to manufacture other hydro-mechanical components.

Officials from BHSL said that the company is hopeful that they would get orders from the North-Eastern region.

BHSL could reclaim over 45 runners in a year and it takes at least three months to make one depending on the size of the runners.

MHPA’S unit III to resume by next week

Kuensel | Nim Dorji | August 12, 2021

More than nine months after Mangdechhu Hydropower Authority’s (MHPA) turbine unit three broke down, restoration work is expected to complete next week.

MHPA official said that the unit would resume power generation by August 20. The 720MW plant shut down its turbine number three on September 21 last year.

A flashover has resulted in the burning and carbonisation of stator (a stationary part of a rotary system) windings and other rotor components inside the generator causing an electric short-circuit.

Flashover is a kind of spark that may be caused due to vibrations or insulation failure, which has created carbonisation in the machines. Carbonisation is the phenomenon of dirtying of stator windings and other components, with dark dust, inside the turbine when there are sparks or flash thereby causing an electric short-circuit.

The same unit was shut down for three weeks in June last year due to a fault developed in the stator of the turbine.

An official earlier said that such incidents are not fundamentally and electrically very catastrophic.

Such problems, according to officials, were expected during the operation and maintenance period of any new hydropower plant.

A similar flashover followed by carbonisation occurred in one of the turbines before but it was restored within a month.

Lately, the officials have been working round the clock to fix Unit III. Each of the three groups has around 17 workers and they work in three shifts.

It was learnt that workers from different power plants who have experience in the operation and maintenance were brought in to help expedite the restoration work.

According to a project official, the restoration work is almost complete and only two major testings are left. “The open circuit and short circuit will be conducted in the next two days,” the official said.

If everything goes as expected the plant will be put on the grid on August 20.

As of yesterday, the three units generated around 593.12MW. Each unit is generating around 197MW, which is 10 percent additional power above their capacity.

MHPA was completed in 2020 within seven years at a cost of Nu 51.442 billion. Each of the four units generates 180MW of electricity.

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