Southeast Asia has many and diverse hydrological resources, and in the extensive region a number of countries are pushing ahead a wide range of hydropower projects, from small to large, and increasingly co-operating on developments within major international river basins, such as the Mekong. The projects draw upon local capabilities as well as pulling in foreign expertise, and supportive funding, to help serve the growing economies of the region and their energy-hungry industries and populations.

The first few months of this year has seen the 2400MW Son La scheme in Vietnam – the country’s biggest hydro project – settle into its initial operational phase after an impressive construction period. Meanwhile, upstream work continues on the 1200MW Lai Chau scheme, which features – like Son La – a major RCC dam.

Many more hydropower projects are under development in Vietnam, including A Luoi, Song Bac and Song Bung 4 – and there was also the recent refurbishment of the Thak Ba facility – all of which keep the momentum going following plants brought online, such as the A Vuong and Buon Kuop facilities. The Ban Ve project was also recently completed.

In a step forward in strengthening ties in hydro between the country and Norway, renowned for its hydro nous, an office was established late last year by the Norwegian firm SN Power, which is active in many parts of the region, such as The Philippines. The base in Vietnam was set up a few months after SN Power signed a joint venture pact with the International Finance Corporation (IFC) to develop renewable energy projects in the country.

A range of projects are also advancing in Lao PDR. Late last year a milestone was reached on the Theun Hinboun Expansion project with breakthrough on the country’s first TBM-driven tunnel – a key feature of the step-up in output that will come from the existing hydropower infrastructure. The project will give power to Lao PDR and also Thailand, and its development features further Norwegian involvement through the utility Statkraft as well as European contractor input.

Elsewhere in Lao PDR, further European involvement – through Electrite de France (edf) – in hydropower development brought the 1070MW Nam Theun 2 project online at the end of 2010. Also under planning and construction are projects such as the 240MW Don Sahong, 615MW Nam Ngum 2, 440MW Nam Ngum 3 and the 1280MW Xayaburi schemes – to be the first on the Mekong River outside of China.

The design of Xayaburi takes into consideration the guidelines of the mekong-river-commission (MRC) – established to help coordinate the optimum development of the multitude of hydropower and dams projects in the Mekong River basin, the dominate catchment in the region and crossing many international borders. Last September the MRC received official notification from Lao PDR of this proposed landmark mainstream development for the river basin.

In addition, in Lao PDR the Asian Development Bank (ADB) is also supporting small and mini-hydro projects, with some funding assistance also coming through Finland – which, last month, renewed its support for sustainable hydro and training of young professionals in the Mekong river basin, notes MRC.

Alongside ongoing efforts and progress made to increase cooperation on water resources, water quality, environmental mitigation and upstream stretches of the catchment, such as in China and Myanmar – where hydro projects are increasing – the Mekong initiative has also seen the launch, in January, of a tool for sustainable hydropower development in the entire basin.

Vietnam

This year saw Vietnam move ahead in hydro with generation commencing at the Son La multi-purpose scheme on the Da River, approximately 360km north west of Hanoi. The river diversion took place in May 2010 and by December the first of the plant’s six 400MW was generating. alstom Hydro is supplying all electrical-mechanical equipment to the project, due to be completed next year.

A key feature of the project is the 138m high by 900m long RCC dam, which had an effective placement time of just over two years when completed in August 2010. During construction 1Mm3 was placed in the first eight months and productivity peaked at approximately 180,000m3 in the best month. The peripheral spillway has a discharge capacity of 35,000m3/sec.

Son La is being developed by Electricity of VietNam (EVN) for hydropower as well as flood mitigation and irrigation. EVN has supervised the works and construction with support from a consortium of SMEC, Nippon Koei and J Power. The dam design was performed by Swiss consultant AF-Colenco, working as a sub-consultant to the Vietnamese Power Engineering Consulting Joint Stock Co 1 (PECC1).

AF-Colenco is also working on the RCC dam design for the Lai Chau project, which is the country’s third largest hydro scheme. The developer is also EVN, and groundbreaking for the project took place a couple of months ago.

While Lai Chau gets underway, EVN also has the 156MW Song Bung 4 project under development in Quang Nam province, which also includes construction of a RCC dam more than 110m high. The project includes excavation of a 3.2km long headrace, and is due for completion by 2014. Mott MacDonald has been undertaking design reviews and other services to the client’s management board.

While many projects see main construction work getting underway, work on site is in the latetr stages for the 170MW A Luoi project on the A Sap River, in Thua Thien Hue province. The scheme involves a 12km headrace tunnel – which contractor Cavico says is the longest in the country – as well as a surge tank and vertical shaft. The powerhouse is expected to generate about 686GWh of electricity per year. Separately, Cavico is getting underway with excavation for tunnel works on the 42MW Song Bac project, in Ha Giang province.

It is not all new projects in Vietnam, however. The upgrade and refurbishment of the Thak Ba powerhouse continues to proceed well. The plant was built in 1976 and its rated capacity is 120MW, the units having been manufactured a decade earlier by Electrosila, a subsidiary of Power Machines. Now, the Russian manufacturer is completing the works on the third unit to be upgraded from 6MW to 42MW.

Power Machines has also been involved in new projects, such as the Buon Kuop (2 x140MW) and A Vuong (2 x 107MW) schemes in collaboration with Sumitomo. In addition, the Russian manufacturer was also the supplier of the turbines packages (2 x 55MW) to the Pleykrong project.

To further push forward hydro and other renewables developments in Vietnam, SN Power last year solidified its presence in the country by opening a office in Hanoi office and striking the JV pact with IFC – the private sector support arm of The World Bank Group – for energy projects in the country.

SN Power said it wants to find viable hydropower projects to develop and operate, and says the deal with IFC will help it to do so.

IFC sees the JV gearing up in Vietnam as an extension of the partners co-operation in renewables elsewhere. At the opening of the SN Power office, IFC’s regional manager, Simon Andrews, said: “This partnership will pave the way for a strong portfolio of renewable energy projects that will make critical contributions to sustainable and environmentally sound economic development of the country.”

The Norwegian Ambassador, Stale Risa, said the involvement of state-owned SN Power signalled the country’s interest in Vietnam.

Lao PDR

The Norwegian presence is also across the border in Lao PDR where Statkraft has been working with Electricite du Laos and GMS Power of Thailand, operating as GMS Lao, to develop the Theun Hinboun Expansion project, which will more than double the capacity of the complex from the existing 220MW. The project has also brought in a range of further international parties, from Cavico next door in Vietnam working as tunnelling subcontractor to Italian main contractor CMC, to Italian manufacturer Euroform, Swedish consultant Sweco, and the Austrian and US manufacturers andritz Hydro and Robbins, respectively.

The most recent milestone of the project was breakthrough, in November 2010, of the 7.6m diameter Robbins TBM on the headrace tunnel – and the country’s first shield-driven bore, says the manufacturer.

Sweco performed the feasibility study and produced the tender documentation for the Theun Hinboun Expansion Project, following its appointment in 2006. The consultant has continued on the scheme by providing services covering design review, contract management and construction supervision.

The expansion project will take water from the Theun Hinboun – a major tributary of the Mekong. In addition to the tunnel, the project infrastructure includes a 70m high RCC dam and two powerhouses of 220MW and 60MW capacities, respectively. The electricity generated by the scheme will be shared between Lao PDR and Thailand, thanks to the separate plants and their corresponding independent transmission lines, when the scheme goes online next year.

While the expansion project adds to the existing asset, the enlarged scheme is less than half the capacity of the country’s largest hydropower facility – Nam Theun 2 – which began operations last year. Again, the output is being split between Thailand and Lao PDR, the bulk going to the former. The scheme is Lao PDR’s biggest economic asset and is capable of producing an average of 6000GWh of electricity per year.

Nam Theun 2 has been built by a JV led by EDF and has had significant support from the World Bank and ADB. It is also cited in the report the ADB Institute published last year on crossborder financing of infrastructure projects.

Aecom has provided services to Nam Theun 2 and is also working on the much smaller, but by no means small, Don Sahong project which is being developed by Mega First Corp Bhd.

Also under development are two further projects on the Nam Ngum River. AF-Colenco is working on the Nam Ngum 2 scheme, which has a 181m high CFRD dam and three 205MW Francis units and completes this year. For the Nam Ngum 3 project the tender documents were revised by SMEC, which produced a RCC dam design that superceded the previous proposal for a CFRD structure.

Presently, final information is being gathered for the Board of ADB to decide, in May, on loan applications for Nam Ngum 3. But while it is assessing the larger scheme the bank is also providing funding for small and mini hydro development in Lao PDR – two tranches of US$10M are sought by the Government to take forward the initiative.

When it is built, the run-of-river Xayaburi scheme on the Mekong will be bigger than Nam Theun 2 – and, once again, the majority of energy production is earmarked for export to Thailand. The project location is about 160km north west of the capital, Vientiane, and AF-Colenco has helped to advance the design and preparations for Thai developer CH. Karnchang Public Co Ltd, and cooperated on the feasibility study with TEAM Consulting Engineering and Management Co Ltd of Thailand.

The Xayaburi powerhouse is to hold seven 175MW Kaplan units plus an eight unit of 60MW capacity. Its spillway is to be formed of 10 gates, each 19m wide by 21m high, and has a total discharge capability for a probable maximum flood (PMF) of 47,500m3/sec. The project will also feature a navigation lock and fish passage facilities.

Mekong Basin

The design of Xayaburi has taken into consideration the current guidelines of the MRC, which aims to implement consistent criteria for all hydropower schemes proposed for the main section of the Mekong basin, which is shared by Lao PDR, Thailand, Cambodia and Vietnam.

For the wider needs of assessing hydro developments, the latest version of the Rapid Basin-wide Hydropower Sustainability Assessment Tool was produced just over half a year ago. The tool was prepared by Entura for USAID, which has been collaborating on the Mekong initiative with MRC and its partners, ADB and WWF.

The tool has been developed under an initiative, established almost five year ago – Environmental Considerations for Sustainable Hydropower Development (ECSHD) – that takes a whole-life cycle perspective, from planning, design, construction to operations. The ECSHD initiative is led by MRC, ADB and WWF. The new tool builds upon previous work by the Hydropower Sustainability Assessment Forum (HSAF) and the international-hydropower-association (iha).

Myanmar

Hydropower developments in Myanmar are increasing, and have seen major dam construction productivity achievements in the likes of the RCC work on the 790MW Yeywa scheme. The 134m high dam was built by Chinese firm Gezhouba Water & Power.

AF-Colenco has been involved in the Yeywa project, and is also helping to take forward the 140MW Upper Paunglaung project which will have the second RCC dam in the country and the first to be built be local contractors. The project is located on the Paunglaung River and features a 103m high by 530m long RCC dam with an ungated central spillway. Downstream is the existing 280MW Paunglaung plant.

Concrete placement for the Upper Paunglaung dam is scheduled to be getting underway shortly, and the dam has an ambitious target of being completed in 2012. The powerhouse at the toe of the dam is to hold a pair of 70MW Francis units.

Elsewhere in the country, hydro developments in the Chindwin basin have been targeted by India’s NHPC in a strategic pact with the Ministry of Electric Power No 1. Projects include Htamanthi and Shwesayay.

Malaysia, Philippines

Beyond the Mekong basin, the jewel of hydro development is the Bakun scheme in Malaysia. For decades the scheme was examined and led to various attempts to construct the asset, but this year the 2400MW (8 x 400MW) scheme – developed, in the end, by Malaysia-China Hydro JV – will be completed.

Bakun includes the world’s second largest CFRD dam, which is to be 230m high upon completion. Entura is providing consultancy advice of dam safety for the project to the Sarawak Ministry of Public Utilities.

The consultant is also heavily involved in development studies for Sarawak Energy Bhd, the state-owned utility with a 30-year plan to develop 20GW of hydropower. Locations where initial feasibility studies have been undertaken include Metjawah, Belaga, Punun Bah and Pelagus.

An Australian compatriot, SMEC, is also active in Malaysia – on the 372MW Ulu Jelai scheme, its largest international scheme so far. SMEC is also active in the Philippines, assisting First Gen Mindanao Hydro Power Corp – in its development JV, with Mindanao Energy Systems – for the design of the Bubunawan 2 scheme. The consultant is also helping First Gen with development of the Puyo project. Separately, it is also advising SN Aboitiz Power on a pumped storage addition to the privatised 360MW Magat facility.