Hydropower systems in high mountain areas need to be better adapted to climate change: NUS study

Pangong Lake in the Himalayas. Glaciers or glacial lakes at high altitudes are vulnerable to global warming. Image: ST File

From The Straits Times

SINGAPORE – Power generation through harnessing water, one of the world’s largest renewable sources of electricity, is coming increasingly under threat in the Himalayan mountains and neighbouring ranges because of climate change-related disasters.

Many new hydropower projects are planned near glaciers or glacial lakes at high altitudes – which are vulnerable to global warming.

Better adaptation measures and more robust planning and monitoring systems are urgently needed, said a new study led by the National University of Singapore (NUS).

Known collectively as High Mountain Asia, this region has the largest reserves of water in the form of ice and snow outside the polar region.

Its glaciers, which provide water for drinking and agricultural use, also represent largely untapped potential for hydropower.

There are more than 650 hydropower projects either under construction or planned in the Himalayan region, with the hydropower potential in the High Mountain Asian region exceeding 500 gigawatts of energy, enough to support more than 350 million homes.

But only about 20 per cent of the estimated 500GW potential has been tapped so far.

Dr Dongfeng Li, the study’s lead author and a research fellow in NUS’ Department of Geography, said the study was motivated by recent hydropower plant failures in the Himalayas.

The team wanted to study the link between these mountainous hazards and climate change.

In February last year, an avalanche hit a Himalayan glacial valley in the Chamoli District of Uttarakhand, India, resulting in a cascade of debris and disastrous flooding that swept away two hydropower projects.

Conducted in collaboration with scientists from countries such as Britain, Nepal and Australia, the study, published in the journal Nature Geoscience on June 23, recommended climate change-resilient hydropower systems in high mountainous areas.

The study found that global warming-induced melting of ice systems is severely altering the volume and timing of water supplied from High Mountain Asia to downstream areas, which people rely on for food and energy.

The construction of more reservoirs to regulate stream flow and produce hydropower is a critical part of strategies for adapting to these changes.

However, these adaptation projects themselves are vulnerable to a complex set of interacting processes, including melting glaciers, the thawing of permafrost which results in landslides, as well as debris flows and floods from glacial lakes.

These processes can mobilise large amounts of sediments, which then fill up reservoirs, causing dam failure and degrading power turbines.

Professor Xixi Lu, also from NUS’ Department of Geography, the second author of the study, said future reservoirs should have additional storage space to cope with increased sedimentation from potential climate-related hazards.

The study also suggested that maps be created to better delineate current and future hazard-prone regions, particularly for hydropower plant hot spots.

These maps should inform policies for maintaining current hydropower plants and planning for new ones.

In addition, monitoring, forecasting and early-warning systems for future disasters should also be further developed and implemented.

Author: Cheryl Tan

Thailand makes green push with floating hydro-solar power project

The Sirindhorn floating solar farm is the largest hybrid project of its kind in the world. Image: Jack Board

From Channel News Asia

UBON RATCHATHANI: A vast array of solar panels floats on the shimmering waters of a reservoir in northeast Thailand, symbolising the kingdom’s drive towards clean energy as it seeks carbon neutrality by 2050.

The immense installation, covering 720,000 sq m of water surface, is a hybrid system that converts sunlight to electricity by day and generates hydropower at night.

Touted by the authorities as the “world’s largest floating hydro-solar farm”, the Sirindhorn dam project in the northeastern province of Ubon Ratchathani is the first of 15 such farms Thailand plans to build by 2037.

The kingdom is stepping up efforts to wean itself off fossil fuels, and at the COP26 climate conference in Glasgow last year, Prime Minister Prayut Chan-O-Cha set the target of carbon neutrality by 2050 followed by a net-zero greenhouse emissions by 2065.

The Sirindhorn dam farm – which began operations last October – has more than 144,000 solar cells, covering the same area as 70 football pitches, and can generate 45 MW of electricity.

“We can claim that through 45 megawatts combined with hydropower and energy management system for solar and hydro powers, this is the first and biggest project in the world,” Electricity Generating Authority of Thailand (EGAT) deputy governor Prasertsak Cherngchawano told AFP.

The hybrid energy project aims to reduce carbon dioxide emissions by 47,000 tonnes per year and to support Thailand’s push toward generating 30 per cent of its energy from renewables by 2037, according to EGAT.

Each solar panel at Sirindhorn Dam is 1m by 2m. Image: Jack Board

Green Shift

But hitting these targets will require a major revamp of power generation.

Thailand still relies heavily on fossil fuel, with 55 per cent of power derived from natural gas as of October last year, compared with 11 per cent from renewables and hydropower, according to the Energy Policy and Planning Office, a department of the ministry of energy.

EGAT plans to gradually install floating hydro-solar farms in 15 more dams across Thailand by 2037, with a total power generation capacity of 2,725 MW.

The US$35 million Sirindhorn project took nearly two years to build – including COVID-19 hold-ups caused by delays to solar panel deliveries and technicians falling sick.

Most of the electricity generated by the floating hydro-solar farm goes to the provincial electricity authority, which distributes power to homes and businesses in provinces in the lower northeastern region of Thailand.

A worker kneels by one of the solar cell panels over the water surface of Sirindhorn Dam in Ubon Ratchathani, Thailand on Apr 8, 2021. Image: Reuters/Prapan Chankaew

Tourism Potential

As well as generating power, officials hope the giant solar farm will also prove a draw for tourists.

A 415m-long “Nature Walkway” shaped like a sunray has been installed to give panoramic views of the reservoir and floating solar cells.

“When I learned that this dam has the world’s biggest hydro-solar farm, I knew it’s worth seeing with my own eyes,” tourist Duangrat Meesit, 46, told AFP.

Some locals have reservations about the floating hydro-solar farm, with fishermen complaining they have been forced to change where they cast their nets.

“The number of fish caught has reduced, so we have less income,” village headman Thongphon Mobmai, 64, told AFP.

“But locals have to accept this mandate for community development envisioned by the state.”

But the electricity generating authority insists the project will not affect agriculture, fishing or other community activities.

“We’ve used only 0.2 to 0.3 per cent of the dam’s surface area. People can make use of lands for agriculture, residency, and other purposes,” said EGAT’s Prasertsak.