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Is Hydropower Renewable or Nonrenewable

When diving into the world of energy resources, a recurring question arises: is hydropower renewable or nonrenewable? It’s a conundrum that demands a nuanced response, intertwined with an understanding of how hydropower works and its impact on the environment.

tl;dr: Hydropower is generally considered a renewable energy source because it harnesses the natural water cycle to produce electricity. However, there are environmental considerations and operational limitations that can sometimes blur this classification. Still, when compared to fossil fuels, hydropower leaves a significantly lighter carbon footprint.

Understanding Hydropower

Hydropower, also known as hydroelectric power, leverages the energy of flowing water to produce electricity. This is typically achieved through dams that store vast amounts of water. As this water is released, it flows through turbines, converting kinetic energy into mechanical energy, which is then transformed into electricity.

The process can be compared to the age-old use of water wheels in rivers – only at a much larger and efficient scale. Source

Why Hydropower is Considered Renewable

  1. Natural Water Cycle: Hydropower relies on the Earth’s natural water cycle. As long as water evaporates, forms clouds, and falls back to Earth as precipitation, we will have flowing water to tap into for power generation. The continuous nature of this cycle ensures that water – the primary “fuel” for hydropower – does not run out.
  2. Low Emissions: One of the hallmarks of renewable energy sources is their low impact on carbon emissions. Hydropower is no exception. While dams can produce greenhouse gases due to the decomposition of organic material in their reservoirs, these emissions are minimal compared to those from coal or natural gas plants. A study from the Intergovernmental Panel on Climate Change (IPCC) affirmed this, suggesting that hydropower emits 30-60 times less carbon compared to fossil-based systems.
  3. Regeneration: Unlike fossil fuels which deplete over time, the water used in hydropower is continuously replenished through natural processes, solidifying its place in the renewable category.

The Gray Area: Environmental and Operational Concerns

While hydropower’s renewable credentials are impressive, certain caveats muddle the waters (pun intended).

  1. Environmental Impact on Aquatic Life: Dams can have profound effects on aquatic ecosystems, potentially harming fish populations, including endangered species. Some fish, like salmon, need to migrate upstream to spawn, and dams can inhibit this migration. While fish ladders and other mitigation measures have been introduced in some projects, they aren’t always effective. Research from the National Renewable Energy Laboratory highlights these challenges.
  2. Reservoir Emissions: As mentioned, reservoirs can produce greenhouse gases. In tropical areas, these emissions can sometimes rival those of fossil fuel plants. A study conducted in Brazil discovered that certain reservoirs had methane emissions comparable to coal-powered plants.
  3. Operational Limitations: A reservoir can only store a finite amount of water. In times of prolonged drought, there might not be enough water flow to produce the desired electricity. Hence, while water as a resource is renewable, the operational capability of a hydropower plant might not always be consistent.

Hydropower vs. Other Renewables

It’s important to juxtapose hydropower with other renewables like solar or wind. Each has its merits and challenges. For instance, while hydropower can offer consistent power (barring drought conditions), solar and wind are intermittent. Yet, solar and wind farms typically have less environmental impact than large hydropower dams.

Note: The optimal energy mix for any region often involves a combination of multiple renewable resources, maximizing benefits and offsetting individual weaknesses.

Hydropower’s Societal and Economic Impacts

While the environmental aspects of hydropower often dominate the conversation, it’s also essential to consider the broader societal and economic implications of hydroelectric projects.

Displacement of Local Communities

Large hydropower projects often require the construction of vast reservoirs. The creation of such reservoirs can submerge extensive land areas, leading to the displacement of local communities. The Three Gorges Dam in China, for example, is one of the most significant hydroelectric projects globally, and it resulted in the displacement of more than a million people. Source

Note: Displaced communities often suffer from loss of ancestral lands, cultural heritage, and traditional livelihoods, leading to socio-economic hardships.

Economic Benefits and Job Creation

On the flip side, hydropower projects can be significant drivers of economic development. They offer job opportunities during the construction phase and continued operation and maintenance roles post-construction. Regions with abundant hydropower potential can also benefit from electricity exports, bolstering their economy.

For instance, Norway, with its mountainous terrain and numerous water bodies, harnesses hydropower to cater to over 95% of its electricity needs and often exports surplus electricity to neighboring countries. This has positioned Norway as a net exporter of energy in Europe. Source

Balancing Energy Grids and Supporting Other Renewables

Hydropower, especially when equipped with pumped storage facilities, can balance energy grids. During periods of low electricity demand, excess electricity can be used to pump water to higher reservoirs. When demand rises, this water is released to produce electricity, acting as a giant battery.

This capability makes hydropower a valuable companion for intermittent renewables like wind and solar. For instance, when there’s a surplus of solar energy on a sunny day, pumped storage facilities can store some of this excess energy, releasing it during the night or cloudy days. Reference from the U.S. Energy Information Administration (EIA)

Water Resource Management and Other Uses

Beyond electricity generation, reservoirs created by hydropower projects often serve multiple purposes, offering recreational opportunities like boating and fishing. They can also be valuable resources for irrigation, especially in arid regions, and play a role in flood control.

However, there’s a trade-off. For example, maintaining a reservoir at a high level might be optimal for electricity generation, but this might conflict with flood control objectives which might require lower reservoir levels, especially before heavy rainfalls. Balancing these multiple demands is a complex task for dam operators.

Safety Concerns

Dam safety is a crucial aspect to consider. Poorly maintained or designed dams pose a significant risk, as their failure can result in catastrophic flooding downstream. An infamous case is the Banqiao Dam failure in China in 1975, which resulted in significant loss of life and property. Source

Innovations in Hydropower Technology

While traditional dam-based hydropower systems are most common, innovations are emerging in the sector:

  1. Run-of-the-River Systems: These systems don’t rely on large reservoirs. Instead, they divert a portion of a river’s flow through turbines before returning it downstream. This design minimizes the environmental and social impacts associated with large reservoirs.
  2. Tidal and Wave Energy: Harnessing the energy from ocean tides and waves is a subset of hydropower. As technology in this field matures, it could provide a more consistent energy source than solar or wind, given the predictability of tidal cycles. Reference from the Office of Energy Efficiency & Renewable Energy
  3. Enhanced Turbine Designs: Modern turbine designs are increasingly fish-friendly, minimizing harm to aquatic life passing through. Research in this area aims to optimize energy generation while mitigating environmental impacts.

In essence, while hydropower’s foundational principles remain consistent, the technologies and methodologies surrounding its harnessing are ever-evolving, reflecting our growing understanding of its broader implications and our commitment to sustainability.

The Global Perspective on Hydropower

To understand hydropower’s place in the world of energy, we need to zoom out and consider its global footprint and its geopolitical ramifications.

Hydropower’s Share in the Global Energy Mix

Hydropower holds a significant place in the worldwide renewable energy portfolio. As of the last comprehensive assessment, hydropower contributed about 16% of the world’s electricity generation, making it the largest renewable electricity source globally.

Countries like Brazil, Canada, China, and Russia boast vast hydroelectric capacities, tapping into their abundant river systems. These nations, combined with a few others, account for over 50% of global hydropower production.

Geopolitical Ramifications of Hydropower

Hydropower isn’t just about electricity; it’s also about water – a crucial resource that often transcends borders. Large hydropower projects on shared rivers can become hotspots for international tensions.

For instance, the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile, primarily a hydropower project, has been a point of contention between Ethiopia, Sudan, and Egypt. According to the BBC The dam’s reservoir-filling strategy and its long-term operation have raised concerns about water availability downstream, especially for Egypt, which heavily relies on the Nile.

Note: International agreements, diplomacy, and shared benefits are essential for such transboundary hydropower projects to ensure equitable water and energy distribution.

Hydropower’s Contribution to Climate Resilience

While hydropower itself is susceptible to the effects of climate change (consider variable rainfall patterns and prolonged droughts), it can also play a role in mitigating climate change consequences.

Hydropower reservoirs, with proper management, can act as buffers during dry spells, ensuring a steady water supply for downstream users. They can also prevent floods by regulating water discharge during heavy rainfalls.

The Future of Hydropower: Modernization and Efficiency

As our technology evolves, so does our approach to hydropower. The focus is increasingly on enhancing the efficiency of existing hydropower facilities rather than building new ones. This approach reduces the need to create new reservoirs and their associated environmental and social impacts.

Modernization includes:

  1. Upgrading Turbines: Older turbines can be replaced with newer, more efficient ones that can extract more energy from the same water flow.
  2. Improving Grid Integration: With the rise of diverse renewable energy sources, the integration of hydropower into modern smart grids ensures smooth energy transmission and distribution, adapting to demand in real-time.
  3. Optimizing Reservoir Management: Advanced monitoring and data analytics allow for better reservoir management, optimizing water use for electricity generation, flood control, and other needs.

Decommissioning Aging Dams

As many of the world’s dams age, the question arises: should they be refurbished or decommissioned? Decommissioning can restore river ecosystems and fish migration patterns. In the US, several outdated dams have been removed to achieve these goals, demonstrating the balance between utilizing and conserving natural resources.

To wrap, understanding hydropower demands a multi-faceted approach, taking into account not just the science, but also the societal, environmental, and geopolitical dimensions. While its role as a renewable energy source is firmly established, its broader implications highlight the complexity of our relationship with nature and the resources it offers.

The Ethical Dimensions of Hydropower

Beyond the scientific, economic, and geopolitical considerations, hydropower also opens a Pandora’s box of ethical questions.

Ethical Considerations Towards Nature

Biodiversity and Ecosystems: While we’ve touched upon the environmental impact on aquatic life, there’s more to it. Reservoirs created by dams can inundate forests, grasslands, and other habitats, disrupting ecosystems and endangering flora and fauna. For many species, especially those with limited habitats, this can be catastrophic.

River Dynamics: Rivers, when flowing naturally, transport sediments, ensuring that downstream ecosystems receive nutrients. Dams hinder this flow, leading to sediment buildup in reservoirs, while depriving downstream areas. Over time, this can lead to land degradation, affecting agriculture and natural landscapes.

Rights of Indigenous Communities

Historically, many large dam projects worldwide have been constructed in areas inhabited by indigenous people. The Belo Monte Dam in Brazil, for instance, faced significant opposition from indigenous communities due to concerns over displacement and the degradation of their ancestral lands.

Cultural Heritage: Beyond just displacement, the inundation can submerge areas of cultural significance to these communities, erasing centuries-old connections to their land.

Loss of Livelihoods: Indigenous communities often rely on local ecosystems for their sustenance. A dammed river can disrupt fish populations, which many local communities depend upon, affecting their traditional ways of life.

Evolving Ethics in Hydropower Development

Recognizing these challenges, there’s an emerging trend towards more inclusive and ethical hydropower development.

Stakeholder Engagement: Modern hydropower projects increasingly involve consultations with local communities. It’s an acknowledgment that those who live on the land have a vital stake in its future. Involving local voices ensures that projects are more aligned with local needs and minimize negative impacts.

Environmental Impact Assessments (EIA): Before initiating major hydropower projects, many nations now mandate comprehensive EIAs. These assessments gauge the potential environmental fallout and ensure that mitigation measures are in place before construction begins.

Compensation and Rehabilitation: Recognizing the inevitable displacement some projects cause, there’s an emphasis on proper compensation, not just in monetary terms but also by providing alternative livelihoods, training, and relocation to regions with similar cultural and environmental contexts.

Small-Scale Hydropower: An Ethical Alternative?

Given the colossal impacts of large dams, there’s growing interest in small-scale hydropower. These systems, often run-of-the-river, have limited storage and minimize environmental and societal impacts. While their energy output might be modest compared to mega-dams, they’re more palatable from an ethical standpoint.

Decentralization: Small-scale hydropower projects can empower local communities, giving them control over their power generation without relying on expansive national grids. This decentralization can invigorate local economies and democratize energy access.

The Dilemma: Energy Needs vs. Ethical Responsibilities

The world’s burgeoning energy needs, driven by population growth and rising living standards, pose a challenge. How do we meet these needs while upholding our ethical responsibilities?

Hydropower, with its vast potential, presents a solution but also forces us to ask hard questions. As with many aspects of development, it’s a tightrope walk, balancing progress with preservation.

In essence, the ethics of hydropower push us to introspect, to evaluate not just the kWh produced, but the unseen costs, urging us towards a more holistic and humane approach to our planet and its inhabitants.


The multifaceted nature of hydropower forces us to evaluate its pros and cons within various dimensions. While it provides a significant chunk of the world’s renewable energy, the direct and indirect impacts on the environment, societies, and geopolitical landscapes cannot be ignored.

Modern approaches to hydropower development aim to balance these considerations, focusing on stakeholder engagement, environmental assessments, and more decentralized, small-scale projects. Like many facets of sustainable development, hydropower poses challenging questions, pushing us to harmonize our immediate needs with long-term responsibilities.


Is hydropower renewable or non-renewable?

Hydropower is considered renewable because it relies on the water cycle, a natural and ongoing process. However, certain aspects, like the construction materials for dams and the finite nature of water in certain regions, introduce nuances to this definition.

What are the environmental impacts of hydropower?

While hydropower avoids greenhouse gas emissions during operation, damming rivers can lead to methane emissions from submerged vegetation, impact fish migration, and alter local ecosystems.

Can hydropower support other renewable energy sources?

Yes, especially those with pumped storage facilities. They can balance energy grids by acting as storage during periods of excess electricity generation from sources like wind or solar and releasing stored energy during periods of high demand.

What are the social implications of large hydropower projects?

Large projects can lead to the displacement of local communities, loss of ancestral lands, and socio-economic upheavals. However, they also offer job opportunities and can drive regional economic development.

Are there ethical concerns related to hydropower development?

Yes, especially concerning the rights of indigenous communities and the environmental stewardship of rivers and ecosystems. Modern hydropower planning emphasizes stakeholder consultations, impact assessments, and compensation schemes to address these concerns.


  • Chris Chamberlan

    Chris Chamberlan, passionate animal welfare activist and USC graduate, conducted undercover RSPCA missions exposing slaughterhouse malpractices. A vegan and advocate for humane treatment, Chris has spoken at international conferences, been involved in vegan outreach, and founded Solarpunk Solutions for sustainability. His blending of animal welfare with eco-living principles for a compassionate future.

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