Solar Energy in Bhutan

Bhutan's energy identity is inseparable from hydropower, which provides virtually all of the country's electricity generation and constitutes its single largest export commodity through sales to India. Yet this overwhelming dependence on a single energy source, despite its renewable credentials, creates vulnerabilities that have prompted the Royal Government to look beyond water for its energy future. Solar energy — abundant in Bhutan's high-altitude environment where solar irradiance levels are among the highest in the region — has emerged as the most promising complementary renewable resource, offering the potential to address seasonal electricity deficits, reach remote communities beyond the hydropower grid, and further strengthen Bhutan's position as the world's only carbon-negative country.^[1]

The case for solar energy in Bhutan rests on a fundamental seasonal mismatch in the hydropower system. Bhutan's run-of-river hydropower plants generate their maximum output during the summer monsoon months (June to September) when river flows are highest, but electricity demand peaks during the winter months (November to February) when flows are at their lowest. During winter, Bhutan must import electricity from India to meet domestic demand — a paradox for a country that exports surplus power for most of the year. Solar energy, whose generation profile is relatively consistent year-round with higher output during the dry, clear winter months, offers a natural complement to the hydropower seasonal cycle.^[2]

Solar Potential and Resource Assessment

Bhutan's solar energy potential is substantial, though geographically variable. Solar irradiance across the country averages approximately 4.0 to 5.5 kilowatt-hours per square metre per day, with the highest values in the southern foothills and western valleys, and lower but still viable levels in the north and at higher altitudes where cloud cover is more frequent. A comprehensive solar resource assessment conducted by the Department of Renewable Energy with support from the Asian Development Bank in 2017-2018 identified technically feasible solar potential exceeding 12,000 megawatts — far more than the country could conceivably utilise in the foreseeable future, given total installed electricity capacity of approximately 2,300 megawatts (almost entirely hydropower) as of 2024.^[3]

The assessment identified particularly suitable sites in the Paro, Wangdue Phodrang, Punakha, and Sarpang districts, where combinations of high irradiance, available land, and proximity to transmission infrastructure make utility-scale solar development economically attractive. However, land availability is constrained in Bhutan's narrow valleys, where agricultural land is scarce and competing demands for housing, roads, and other development are intense. Rooftop solar, which avoids land use conflicts, is considered the most practical pathway for significant solar deployment in urban areas.^[2]

Current Installations

As of 2024, Bhutan's total installed solar capacity remains modest — approximately 17 to 20 megawatts — but has grown significantly from a negligible base a decade earlier. The growth has been driven by a combination of government demonstration projects, donor-funded installations, and a small but growing number of private and institutional systems. Key installations include:

The 180-kilowatt solar photovoltaic plant at Rubesa in Wangdue Phodrang, one of the first grid-connected solar plants in the country, was commissioned in 2014 as a demonstration project by the Department of Renewable Energy with support from the Austrian Development Agency. While small by international standards, it provided valuable operational experience and data on solar performance in Bhutanese conditions.^[3]

A 7.5 megawatt solar plant near Phuentsholing, developed with ADB financing, represented a significant scale-up and was among the largest solar installations in the country upon commissioning. The project demonstrated the economic viability of grid-connected solar in Bhutan's southern belt, where irradiance levels are highest and proximity to the Indian border facilitates equipment import and potential cross-border power trade.^[2]

Off-grid solar installations — small standalone systems providing electricity to individual households, schools, Basic Health Units, and monasteries in remote areas beyond the reach of the grid — have been deployed in scattered locations across the country since the early 2000s. These systems, typically ranging from 50 watts to several kilowatts, have been funded through a combination of government rural electrification programmes, UNDP and SNV projects, and bilateral aid. While collectively small in capacity, they serve a critical function in providing basic electricity services — lighting, phone charging, and small appliance operation — to some of Bhutan's most isolated communities.^[4]

ADB-Funded Projects and Expansion Plans

The Asian Development Bank has been the most significant international partner in Bhutan's solar energy development. The ADB's Sustainable Power Sector Support Project, approved in 2019, includes a substantial solar component alongside grid strengthening and institutional capacity building. The project aims to add utility-scale solar capacity, deploy battery energy storage systems to manage solar intermittency, and strengthen the grid infrastructure needed to integrate variable renewable generation into a system designed around dispatchable hydropower.^[2]

A flagship ADB initiative is the development of a 30 megawatt solar park with integrated battery storage, planned for a site in the southern region. This project would represent a transformational increase in Bhutan's solar capacity and, importantly, would demonstrate the viability of solar-plus-storage as a model for addressing winter electricity shortages. The battery storage component is critical: without it, solar generation would be concentrated during daytime hours and unable to serve the evening peak demand period. With storage, solar energy can be shifted to hours of highest demand, maximising its value to the grid.^[2]

The government's Alternative Renewable Energy Policy, updated in 2021, set a target of 50 megawatts of solar capacity by 2025 and a longer-term aspiration of integrating solar into the national energy mix as a significant complement to hydropower. While the 2025 target will likely be missed, the policy direction is clear, and subsequent Five-Year Plans have reaffirmed the commitment to solar expansion. The policy framework includes provisions for net metering — allowing solar system owners to sell excess generation back to the grid — which could incentivise rooftop solar adoption by households, businesses, and institutions.^[3]

Rural Electrification and Off-Grid Solar

Bhutan has achieved near-universal electricity access, with the national electrification rate exceeding 99 percent as of 2023 — a remarkable achievement given the country's mountainous terrain and dispersed settlement patterns. However, the final percentage points of electrification are the most difficult and expensive, involving remote communities where grid extension would require disproportionate investment in transmission lines across rugged terrain. For these communities, off-grid solar — either standalone household systems or community mini-grids powered by solar panels with battery storage — represents the most cost-effective and practical electrification solution.^[1]

The Bhutan Power Corporation, the national utility, has integrated off-grid solar into its rural electrification planning, identifying communities where solar mini-grids are the preferred option over grid extension. The UNDP's Rural Renewable Energy Programme supported pilot solar mini-grids in several remote communities, providing electricity for households, schools, and health centres while also powering small productive uses such as grain mills and poultry incubators. These pilot projects have generated valuable lessons about the importance of community ownership, maintenance training, and tariff structures that ensure financial sustainability.^[4]

Connection to Carbon-Negative Status

Bhutan's status as the world's only carbon-negative country — its forests absorb more carbon dioxide than the country emits — is a point of immense national pride and international distinction. Solar energy reinforces this status by providing a pathway to meet growing electricity demand without any carbon emissions, even the negligible lifecycle emissions associated with hydropower reservoir construction. As Bhutan's economy develops and electricity demand grows — driven by urbanisation, industrialisation, and initiatives such as the Gelephu Mindfulness City — maintaining carbon-negative status will require that new generation capacity continues to come from zero-emission sources.^[5]

Bhutan's Nationally Determined Contribution (NDC) under the Paris Agreement commits the country to remaining carbon-neutral, and the government has used international climate forums to advocate for recognition and compensation for the carbon sequestration services provided by small, forested countries. Solar energy expansion supports the credibility of these commitments by demonstrating concrete action to diversify the clean energy portfolio, reduce dependence on imported fossil fuels (Bhutan imports diesel and petrol for transport and some industrial uses), and build resilience against climate-induced changes in hydrological patterns that could affect hydropower output in the future.^[5]

Challenges

Despite its potential, solar energy development in Bhutan faces several practical challenges. Land scarcity in the narrow habitable valleys limits utility-scale deployment. The initial capital cost of solar panels and battery storage, while declining globally, remains significant for a small economy with limited domestic manufacturing capacity. Technical expertise in solar system design, installation, and maintenance is still being developed, requiring continued training and capacity building. And the institutional framework — grid codes, interconnection standards, net metering regulations, and competitive procurement mechanisms — is still maturing.^[3]

The integration of variable solar generation into a grid dominated by hydropower also presents technical challenges. The Bhutan Power Corporation must develop dispatch and balancing capabilities to manage the fluctuations in solar output, particularly during cloudy periods and seasonal transitions. Battery storage helps address this, but adds cost and complexity. International experience from countries that have successfully integrated high shares of solar — including India, whose ambitious solar programme provides a proximate model — offers relevant lessons, and Bhutan's participation in regional power trading through the South Asian electricity grid provides a broader system context within which to manage variability.^[1]

Nevertheless, the trajectory is clear. As costs continue to fall, technology improves, and the limitations of hydropower-only dependence become more apparent in a changing climate, solar energy is poised to play an increasingly important role in Bhutan's energy landscape — a natural complement to the rivers that have powered the kingdom's development, harnessing the Himalayan sun alongside the Himalayan water.

See also

• Renewable Energy in Bhutan Beyond Hydropower
• Ministry of Energy and Natural Resources (Bhutan)

References

1. "Bhutan Power Corporation." Bhutan Power Corporation Ltd.
2. "Bhutan: Overview." Asian Development Bank.
3. "Ministry of Energy and Natural Resources." Royal Government of Bhutan.
4. "UNDP Bhutan." United Nations Development Programme.
5. "Bhutan's Nationally Determined Contribution." United Nations Framework Convention on Climate Change.