Hydropower in Bhutan

Hydropower is the cornerstone of Bhutan's economy, its largest export, and arguably its most significant natural resource. The kingdom's steep Himalayan river gradients, fed by glacial melt and monsoon rainfall, provide an estimated hydroelectric potential of approximately 30,000 megawatts (MW), of which roughly 2,300 MW has been developed as of 2024. Electricity — almost exclusively generated from hydropower — accounts for the single largest share of government revenue, the dominant component of export earnings, and a substantial portion of GDP. The overwhelming majority of Bhutan's hydroelectric output is exported to India under bilateral agreements that form the economic backbone of the Indo-Bhutanese relationship.^[1]

The development of Bhutan's hydropower resources has been the defining economic story of the nation's modern history. Beginning with the commissioning of the Chhukha Hydropower Plant in 1986, a succession of increasingly large projects — each financed primarily by the Government of India through a combination of grants and concessional loans — has transformed Bhutan from a subsistence agricultural economy into a lower-middle-income country with one of the highest per capita rates of clean energy production in the world. This transformation has come with significant benefits, including dramatic improvements in government revenue, infrastructure, and social services, but also with substantial risks, including heavy debt exposure, dependence on a single trading partner, and emerging environmental concerns related to climate change and glacial retreat.^[2]

Hydropower policy is closely linked to the broader development philosophy of Gross National Happiness (GNH), which holds that resource exploitation must be balanced against environmental conservation and community well-being. Bhutan's constitution mandates the maintenance of at least 60 percent forest cover — a provision that constrains the type and scale of hydropower development — and the Five-Year Plans incorporate environmental sustainability as a core planning criterion. The Royal Monetary Authority of Bhutan and the Ministry of Finance manage the fiscal implications of the sector, including the management of hydropower-related debt denominated in Indian rupees.^[3]

Major Hydropower Projects

Bhutan's operational hydropower portfolio is anchored by several major projects, each developed under bilateral agreements with India. The Chhukha Hydropower Plant (336 MW), commissioned in 1986 on the Wang Chhu river, was the first large-scale project and proved the commercial viability of Bhutan's water resources. It was followed by the Kurichhu Hydropower Plant (60 MW), commissioned in 2001 on the Kurichhu river in eastern Bhutan, which was designed in part to electrify the eastern districts and reduce regional economic disparities.^[1]

The Tala Hydropower Plant (1,020 MW), commissioned in 2006-2007 on the Wang Chhu downstream of Chhukha, was a transformative project that tripled Bhutan's generation capacity overnight and remains the country's largest operational plant. The Dagachhu Hydropower Plant (126 MW), commissioned in 2015, was notable as the first hydropower project in Bhutan developed as a public-private partnership with Asian Development Bank financing, rather than under the traditional bilateral India model. Most recently, the Mangdechhu Hydroelectric Project (720 MW), commissioned in 2019 on the Mangdechhu river in Trongsa District, added significantly to Bhutan's generation capacity and export earnings.^[1]

Projects Under Construction

Several major hydropower projects are at various stages of construction, though all have experienced significant delays and cost overruns. The Punatsangchhu-I Hydroelectric Project (1,200 MW) and Punatsangchhu-II Hydroelectric Project (1,020 MW), both located on the Punatsangchhu (Sankosh) river in Wangdue Phodrang District, were originally expected to be commissioned in the mid-2010s but have been delayed by geological challenges, including major landslides at the Punatsangchhu-I site that required redesign of the dam. As of 2024, both projects remain under construction with revised completion timelines that have slipped repeatedly.^[4]

The Nikachhu Hydropower Project (118 MW) in Trongsa District is also under development. Additionally, studies and negotiations continue for future projects that could eventually bring Bhutan's developed capacity closer to the estimated 30,000 MW potential, though the pace of new project initiation has slowed in recent years due to the fiscal burden of existing project debts and the challenges experienced at Punatsangchhu.^[2]

The India Partnership

Virtually all of Bhutan's hydropower development has been financed by India under a bilateral framework that is unique in international development. Under this model, India provides a mix of grants and concessional loans (typically 60 percent grant and 40 percent loan for earlier projects, later shifting to 30 percent grant and 70 percent loan for newer projects) to finance project construction. In return, Bhutan exports the surplus electricity to India at a tariff rate negotiated between the two governments. The electricity is sold to Indian states, particularly West Bengal, Assam, and Bihar, where it contributes to meeting peak demand.^[1]

This arrangement has been enormously beneficial for Bhutan, providing the revenue that financed the country's rapid development gains across health, education, and infrastructure. However, it has also created a deep structural dependence on India as both the primary financier and sole buyer of Bhutan's electricity exports. Tariff negotiations, project cost overruns, and the terms of loan repayment are all shaped by the bilateral relationship, giving India significant leverage over Bhutan's fiscal trajectory. Bhutan has explored the possibility of exporting power to Bangladesh as a way to diversify its customer base, but progress has been slow due to the lack of direct transmission infrastructure and the political complexities of trilateral energy trade in South Asia.^[2]

Debt and Fiscal Concerns

The shift from 60/40 grant-loan ratios in earlier projects to 30/70 in more recent ones has dramatically increased Bhutan's external debt burden. Hydropower-related debt to India constitutes the overwhelming majority of Bhutan's total external debt, which stood at approximately 120 percent of GDP in recent years — a ratio that would be alarming in most countries. However, the Bhutanese government and international institutions such as the IMF have argued that this debt is "self-liquidating," meaning that the projects generate revenue through electricity exports that is sufficient to service and eventually repay the loans. The key assumption underlying this argument is that projects are completed on time and on budget — an assumption that the Punatsangchhu delays and cost overruns have called into question.^[2]

The fiscal risk is compounded by the fact that the debt is denominated in Indian rupees and loan repayments must be made from rupee earnings. During the construction phase of large projects, Bhutan experiences large rupee outflows for imported equipment and materials, which can create rupee liquidity shortages that the Royal Monetary Authority must manage carefully. The ngultrum's peg to the rupee means that these dynamics are directly transmitted into Bhutan's macroeconomic conditions.^[3]

Environmental Concerns and Climate Change

While hydropower is classified as renewable energy and Bhutan prides itself on being one of the few carbon-negative countries in the world, the sector is not without environmental challenges. Run-of-river projects alter river flow patterns, affecting downstream ecosystems, aquatic biodiversity, and communities that depend on rivers for water supply and traditional fishing. Large construction sites in mountainous terrain cause deforestation, soil erosion, and sedimentation. The influx of construction workers — often numbering in the thousands for major projects — places pressure on local communities and ecosystems.^[1]

Climate change poses an emerging threat to the sector's long-term viability. Bhutan's rivers are fed significantly by glacial melt, and the retreat of Himalayan glaciers — well documented by scientific research — could alter river flow patterns over the coming decades, potentially reducing dry-season generation capacity. At the same time, climate change increases the risk of glacial lake outburst floods (GLOFs), which pose catastrophic risks to downstream hydropower infrastructure and communities. The Royal Government has invested in glacial lake monitoring and early warning systems, but the long-term implications of climate change for a hydropower-dependent economy remain a source of concern among planners and environmental scientists.^[2]

Future Potential

With only about 8 percent of its estimated 30,000 MW potential developed, Bhutan's hydropower sector has enormous room for growth. However, the pace of future development will be shaped by several factors: the availability of financing on acceptable terms, the resolution of challenges at existing construction sites, the evolution of the India relationship, the demand for clean energy in the South Asian power market, and the environmental constraints imposed by Bhutan's constitutional and policy commitments to sustainability. The Gelephu Mindfulness City project, which envisions a new economic hub in southern Bhutan, has the potential to create domestic demand for electricity that could reduce Bhutan's dependence on the Indian export market, though the project remains in its early stages.^[3]

Bhutan's hydropower story is ultimately one of extraordinary potential tempered by significant risks. The sector has financed a national transformation that few countries of comparable size and starting conditions have achieved. But the concentration of economic dependence on a single resource, a single buyer, and a single financing partner creates vulnerabilities that the Royal Government, the GNHC, and the Bhutanese people will need to navigate carefully in the decades ahead.^[1]

References

Contributed by Anonymous Contributor, Dallas, Texas