Global review of hydropower developments Mar 2020

Hydropower developments added almost 22GW of installed capacity worldwide in 2018, according to the International Hydropower Association (IHA), the latest year for which data is available. Total capacity stood at 1,292GW with most activity taking place in the fast-growing and emerging economies of East Asia and the Pacific, where projects in China dominated, led by the Baihetan project where underground work includes two powerhouses to accommodate 16 generators.

Fig 1. Hydropower capacity and generation by region

Staying in Asia, the tallest dam in the world has been constructed in Tajikistan in a project that included the challenging excavation of two diversion tunnels and a variety of additional underground works.

Growth was also strong in South America, where a number of large projects are progressing, including the Alto Maipo project in Chile, which will be one of the largest underground hydro plants in the world when complete. In Canada, several major projects are underway, the largest of which, on the Peace River, achieved breakthrough on two diversion tunnels in 2019.

Elsewhere in the world, pumped storage is a focus with major projects including the Snowy 2.0 installation in Australia and Ataqa in Egypt.

East Asia and Pacific

According to IHA statistics, East Asia and the Pacific continue to be the drivers for global hydropower development, adding 9.2GW of capacity in 2018. China accounted for the majority of that, adding 8.54GW to pass 350GW of installed capacity.

Leading the Chinese development is the 16,000MW Baihetan project on the Jinsha River, which includes two underground caverns to house 16 x 1,000MW generating units. Developed by the China Three Gorges Corp, the first group of units are expected to come online in 2021 followed by full commissioning by the end of 2022. Also under construction on the Jinsha River is the 10.2MW Wudongde plant, which includes two underground powerhouses housing 6 x 850MW turbines each.

Fig 2. China leads hydropower growth

Baihetan and Wudongde form the second phase of hydroelectric development on the Jinsha River, following phase one development of the Xiluodu and Xiangjiaba facilities. In total, the scheme will have a combined generating capacity of more than 46,000MW.

In addition to these mega hydropower developments, China is investing in smaller-scale hydro and pumped storage projects as part of a nationwide shift to renewable generation and away from coal generating installations, long the dominant fuel for Chinese power generation.

Beyond China, development of the Greater Mekong region of Myanmar is advancing. The Myanmar Government has issued notices to proceed on both the 1,050MW Shweli 3 project led by the French utility EDF, and the 60MW Deeoko project. Indonesia is also developing its hydropower resources with up to 6GW under construction or in planning.

In Australia are several pumped storage projects, notably the Snowy 2.0 project by Snowy Hydro and the Battery of the Nation initiative in Tasmania. Snowy 2.0 is expected to be complete by 2025 to provide an additional 2,000MW of capacity. From 14 sites investigated, Hydro Tasmania selected three in March 2019 to develop – the Lake Cethana, Lake Rowallan and Tribute Power Station projects. Hydro Tasmania is now undertaking feasibility studies to determine the first site for development.

Elsewhere in the Pacific, hydro developments are being investigated in Papua New Guinea, the Solomon Islands, and on Fiji.

North and Central America

Canada is the focus for development in North America with construction of a number of hydro projects underway. The largest of these is the 1,100MW BC Hydro Site C project on the Peace River, which requires the construction of two 10.3m i.d. concrete-lined diversion tunnels of 700m and 800m length to allow construction of the dam. Excavated using two Sandvik 115 tonne MT 520 roadheaders, the first tunnel broke through in June 2019 after 10 months of excavation, and the second followed in July. Focus is now on lining and finishing the tunnels. The CAN$1.75 billion civil works package, which includes the two diversion tunnels, is being undertaken by Peace River Hydro Partners, a joint venture between ACCIONA Infrastructure and Samsung C&T and is expected to be complete by 2024.

Work is also continuing on the La Romaine project for Hydro-Quebec with the final 245MW La Romaine 4 element due for completion in 2021 bringing the total capacity of the facility to 1,550MW. The 824MW Muskrat Falls project on the Lower Church River in Labrador is expected to come online by the end of the 2020, followed by the 695MW Keeyask project on the Nelson River in Manitoba by the end of 2021. In Alberta, construction of the 75MW Canyon Creek pumped storage project, including a 2.5m i.d. x 7km long headrace, has been approved.

Renewable energy accounts for about two-thirds of power generation in Canada, based largely on its significant hydro resources.

Fig 3. Canada leads the way in North America

Although the USA remains one of the largest producers of hydropower, new projects are slow to progress with investment mostly focused on retrofits of existing facilities, despite the Department of Energy saying 50GW of new capacity could be added by 2050. The majority of this, some 35GW, would be pumped storage, such as the planned 400MW Gordon Butte project in Montana. This state-of-the-art US$1 billion project, with a four-year construction programme, could break ground this year (2020) if an offtake agreement can be signed.

New developments in Mexico have also been slow to materialise, despite ambitious goals by the Government to promote renewable energy within its energy generating strategy.

In Central America, several smaller projects are underway with a number of governments developing ambitious plans. The Government of Honduras, for example, is planning several developments as part of a target to achieve 95% renewable energy in its power generating strategy by 2027. Throughout the region, projects face challenges from legal obstacles and security concerns – with the cancellation of the 631MW Diquís project in Costa Rica at the end of 2018 after objections from indigenous communities a leading example. This would have been the largest hydropower facility in Central America.

South America

Fig 4. Brazil overtook USA in installed capacity in 2018

South America is one of the fastest growing regions for hydropower development in the world, adding close to 4,855MW in 2018, despite the growing challenge posed by climate variability.

Brazil accounts for about two-thirds of installed capacity. One of the largest dams in the world, the Belo Monte Dam complex on the Cingu River in the north of the country, recently commissioned a new turbine, number 18, to bring the capacity of the installation to 11,233MW. Belo Monta could be the last mega project in Brazil, according to the IHA, as the country moves towards a more decentralised network of renewable energy.

Elsewhere, the 2,400MW Itunago project in Columbia is the largest in the country and, when complete, will meet about 18% of electricity demand in the country. It has not been without its challenges. Heavy rainfall in April and May 2018 caused large landslides that blocked the diversion tunnels and caused premature flooding of the reservoir. A sudden temporary unblocking of one of these tunnels subsequently caused flooding downstream. As of August 2019, the spillway was complete and in operation, the first gate of the auxiliary diversion gallery (damaged during the landslides) had been reinstalled, cleaning of the transformer and generator caverns and surge chambers was underway, as was the final closure of the diversion tunnels. Completion is scheduled during 2021.

TBM ready for an Alto Maipo drive in Chile

Projects are underway in Peru, as part of a government commitment to become energy self-sufficient by 2024, as well as in Paraguay, Ecuador, Bolivia and Guyana.

In Chile, the 531MW Alto Maipo project is the largest in the country and, when complete later in 2020, will be one of the largest underground hydropower facilities in the world with more than 70km of tunnels and two powerhouse caverns. It comprises a cascade of two run-of-river plants – the 264MW Alfalfal 2 and 267MW Las Lajas installation. A financial restructuring of the project in 2018 saw the signing of a new construction contract with Strabag, after termination of the original contract with Hochtief and CMC di Ravenna in 2017. The new contract includes the excavation of 18.5km of tunnels as well as construction of the intake structures and a 5km steel pipeline. Strabag had previously been contracted in 2012 to excavate two-thirds of the underground watercourse and powerhouse works, totalling some 46km of tunnels and shafts. Four open gripper TBMs were used to excavate the long tunnels with drill+blast used for the caverns, access tunnels and additional waterway headings.

Africa

Despite having the highest percentage of untapped hydropower potential in the world, according to the IHA, Africa continues to rely on oil, gas and traditional biomass combustion for power generation. Hydropower is expected to grow by about 4,700MW over the next two to three years as major projects come online in Angola, Zambia, Nigeria, and Uganda.

The 2,070MW Lauca project in Angola is expected to become fully operational in 2020 with the commissioning of the final turbine. Constructed by EPC contractor Odebrecht, underground elements included excavation of six 2,000m long penstock tunnels to the underground powerhouse, six tailrace tunnels with gate structures, and an underground powerhouse. Construction is also progressing on the China-financed 2,172MW Caculo-Cabaça project. The US$4.5 billion facility is being built by the China Gezhouba Group and is expected to be completed in 2022.

Fig 5. Africa holds the largest untapped hydro potential

In Zambia, construction of the new 750MW US$2 billion Kafue River facility had been progressing well, according to a Government statement in March 2019. However, reports in September 2019 indicated that construction had been suspended by contractor Sinohydro after the Zambian Government failed to pay. The current status of the project is unclear. Underground elements of the project include a flood release tunnel with a maximum capacity of 1018m³/sec, a 4.4km power tunnel, and a 980m diversion tunnel. The project had been expected to be complete in 2020.

Sinohydro of China is also constructing the 750MW Zungeru plant in Nigeria, the 600MW Karuma plant in Uganda, and the 1,400MW Ataqu pumped storage scheme in Egypt.

The Zungeru project was reported to be 68% complete in December 2019 and is on track for its scheduled completion date of December 2021 with initial power generation beginning in December 2020. The project is financed by the Exim Bank of China, alongside the Nigerian Government. The EPC contract was awarded in 2013 to a consortium comprising China National Electric Engineering Co and Sinohydro. Design and technical services were provided by Kunming Survey and Design Institute, a subsidiary of China Hydropower Engineering Consulting Group.

At Karuma in Uganda, which was expected to be completed in December 2019, underground work has been extensive and included six 238m long x 7.7m diameter tunnels, six 7.7m diameter pressure shafts, six tailrace branch tunnels, two 12.9m diameter x 8.7km tailrace tunnels, and three 12m diameter x 2km long surge tunnels.

Elsewhere in Africa, construction of the controversial 6,000MW Greater Ethiopian Renaissance Dam continues. Mozambique, the Democratic Republic of Congo and Cameroon have also seen interest in developing hydropower plants with the 420MW Nachtigal project in Cameroon being the largest independent hydro project in Africa. Along with the 1,800MW Grand Ewing, the 485MW Kpep and the 365MW Makay projects, Cameroon has the potential to add about 3,000MW of hydropower capacity by 2025.

Fig 6. Hydro is central to European Union energy security

Europe

With the rapid growth of renewable energy, combined with the phasing out of nuclear and traditional generating fuels, such as coal, the onus is on hydropower to maintain a secure, affordable and sustainable energy supply under the European Union Framework Strategy for the Energy Union. Outside of the EU, recent development has taken place in Norway and Turkey.

One major project nearing completion within the EU is the EDF 92MW Romanche-Gavet underground hydropower plant in France, which will replace six existing powerhouses and five dams in the valley, as well as increasing production by 30%. The project is expected to come online in 2020.

South and Central Asia

Fig 7. Hydro development in Central Asia includes tallest dam in the world

Hydropower continues to grow through South and Central Asia, with 3.96GW added in 2018.

In South Asia, major projects have been commissioned in Pakistan, Nepal and Bhutan, while in India, major policy developments have been supportive of hydro. Cross-border trade agreements could boost hydro development in the region.

In Central Asia, construction of the US$3.9 billion 3,600MW Rogun project in Tajikistan by main contractor Salini Impregilo continues after commissioning of the second turbine in September 2019. Featuring what is reportedly the tallest dam in the world, facilitated by two diversion tunnels on the Vakhsh River, work on Rogun also includes a range of underground structures, including headraces, powerhouses, tailraces, and hydraulic tunnels.

Robbins TBM excavated the Dariali headrace in Georgia

There are plans to develop new stations Uzbekistan by UzbekHydroEnergo, as well modernising the existing installations, most of which are between 30 and 80 years old.

Modernisation work is also underway in Russia and across the South Caucasus. In February, PJSC RusHydro announced the inauguration of the 246MW Zaramagskaya-1 plant on the Ardon River in North Ossetia in Russia to include construction of a 14km diversion tunnel. Across the border in Georgia, there is a portfolio of assets in the planning stage, including the 433 Namakhvani project under development by Enka Renewables, formerly the Clean Energy Group Georgia. This follows development of the Dariali hydro project on which two 5.5m diameter Robbins main beam TBMs excavated the 5km long headrace.

Forward planning and goals

Hydro installations produce almost two-thirds of global renewable energy, according to the IHA. It is not without its challenges, however, with extreme rock conditions, often under high overburdens, causing major excavation difficulties and delays and obstructing the possibility of adequate geological investigations ahead of main excavation works. Changes to global climate are also impacting water availability to support hydro development across the world. Despite this, it remains an important option in the development of a clean, reliable energy network, with 48 countries adding capacity in 2018.

Hydropower “is making a major contribution to delivering on the ambitions of the United Nations Sustainable Development Goals,” concluded the IHA. “Without this contribution, the objectives of limiting climate change to 1.5 or 2 degrees above pre-industrial levels would likely be out of reach.”