Why Hydropower Is The Forgotten Giant Of Clean Energy?

When it comes to renewable energy sources, the spotlight often shines on solar and wind power. However, one major renewable power source is frequently overlooked – hydropower. Despite accounting for over half of U.S. renewable electricity generation, hydropower seems to fly under the radar. With a long history providing affordable and reliable electricity, hydropower is a forgotten giant of renewable energy. This article will dive into the history, capacity, generation, pros, cons, and future of hydropower to rediscover its importance.

History and Background

Hydropower has been used for thousands of years, dating back to ancient Greece when water wheels were utilized for grinding grain. Some of the earliest innovations in harnessing the power of water were developed in China during the Han Dynasty between 202 BC and 220 AD, using paddle wheels to operate mills for tasks like grain processing and iron works. [1]

The modern era of hydropower began in the late 19th century with the opening of the first hydroelectric plant in Wisconsin in 1882 and the first plant in California in 1887. By 1907, hydropower provided 15% of U.S. electrical generation. The development of major hydroelectric projects like Hoover Dam, Grand Coulee Dam and others in the early-to-mid 20th century helped expand hydropower capacity in America. [2]

Hydropower continued to grow steadily through the mid-20th century. The technology was widely adopted around the world, and today it remains the most significant renewable energy source for electrical power generation globally. However, growth in hydro capacity has slowed in recent decades in many countries.

Hydropower Capacity

Hydropower accounts for over 16% of electricity generation globally, providing an installed capacity of 1,308 GW as of 2022 (Source). China has the highest installed hydropower capacity at 414.8 GW, representing over 30% of the global total. Other top countries by installed capacity include Brazil (109 GW), Canada (83.6 GW), the United States (80 GW), and Russia (49 GW). While growth in hydropower capacity has slowed in recent years, it still remains a major source of renewable electricity around the world.

Hydropower Generation

Hydropower generated over 4,350 terawatt hours of electricity globally in 2021, meeting about 16% of the world’s electricity demand according to the International Hydropower Association (https://www.hydropower.org/factsheets/hydropower-factsheet). In terms of generation by country, China leads the world by a large margin, generating over 1,300 TWh of hydropower electricity annually. This accounts for 29% of the world’s hydropower generation. Other top generating countries include Brazil (428 TWh), Canada (392 TWh), the United States (260 TWh), and Russia (214 TWh) (https://www.statista.com/statistics/474799/global-hydropower-generation-by-major-country/). Hydropower provides over half of the electricity generation in several countries including Brazil, Norway, Venezuela, and Canada.

Advantages

Hydropower has many advantages that make it an attractive energy source. Three of the main benefits are that it is renewable, flexible, and has low operating costs.

Hydropower is considered a renewable energy source because it relies on the water cycle. As long as there is a flow of water, electricity can be generated. The sun’s heat causes water to evaporate and form clouds. This water eventually falls back to earth as rain or snow, supplying rivers and streams [1]. This natural process makes hydropower an inexhaustible resource.

Hydropower systems are also very flexible. The flow of water can be easily controlled using valves and gates to match energy demands. Hydropower plants can start up quickly and adjust output to meet sudden spikes or drops in electricity requirements [1]. This allows hydropower to complement other renewables like wind and solar which fluctuate based on weather conditions.

Lastly, after a hydropower plant has been built, operating costs are relatively low. Once the infrastructure is in place, the source of the energy, flowing water, is free. Operation and maintenance costs average around 3-5 cents per kilowatt-hour. This makes hydropower very affordable compared to fossil fuels [1].

[1] https://www.energy.gov/eere/water/benefits-hydropower

Disadvantages

Hydropower comes with some notable disadvantages as well. The most significant drawback is the high upfront costs associated with building large dams and reservoirs. The infrastructure required such as concrete, turbines, and transmission lines makes hydropower one of the most capital intensive energy sources to develop.

Hydropower facilities also lead to localized environmental impacts around the dam and reservoir area. Building large dams floods areas upstream and changes the natural water flow, which can negatively affect local wildlife habitats, vegetation, and water quality [1]. Fish migration can be blocked and populations disrupted. Methane emissions may also be generated when vegetation decomposes underwater [2].

Development Challenges

While hydropower has many benefits, expanding hydropower faces some challenges. Two major hurdles for new hydropower development are difficulty finding new quality sites and regulatory issues.

Many of the best locations for hydropower dams have already been utilized, leaving mostly marginal sites available for new projects. Building dams in remote areas or with less than ideal hydrology can increase costs and lower power generation efficiency (Fuergy). Finding sites with adequate water flow year-round is becoming more difficult with climate change impacting precipitation patterns.

New hydropower projects also face long regulatory approval processes. Extensive environmental impact assessments and permitting are required, which can take 5-10 years before construction even begins (Pokhrel). Conflicts over water rights and usage as well as public opposition to damming free-flowing rivers further complicate the approval process.

Future Outlook

Hydropower is projected to continue expanding globally in the coming decades. According to the International Energy Agency, global hydropower capacity is forecast to increase by 17%, or 230 GW, between 2021 and 2030. This growth will be driven by rising electricity demand and efforts to increase renewable energy usage and reduce carbon emissions. The IEA projects hydropower will provide 16% of global electricity generation by 2040. While most growth is expected in developing countries, particularly in Asia, mature markets like North America and Europe are also projected to expand hydropower capacity. For example, the U.S. Department of Energy’s Hydropower Vision report forecasts U.S. hydropower capacity growing from 101 GW in 2015 to nearly 150 GW in 2050, with generation increasing from 7% to 11% of U.S. electricity. Realizing this potential will require surmounting challenges like upfront costs and licensing hurdles.

Rediscovering Hydropower

Hydropower has largely been overlooked in recent years as attention has shifted to other renewable energy sources like wind and solar. However, there are several ways we can re-prioritize hydropower to maximize its benefits:

First, we need to recognize hydropower’s advantages as a reliable, flexible, and low-cost source of renewable energy. Hydropower should be valued for its ability to store energy and quickly ramp up or down to meet shifts in electricity demand¹. Policymakers and energy planners should factor in these unique strengths when evaluating options for clean electricity generation.

Upgrading existing hydropower facilities with advanced technologies like variable speed turbines and pumped storage can boost output and flexibility². Streamlining regulatory and permitting processes could also facilitate these beneficial upgrades to maximize output from current dams.

Lastly, development of new pumped storage hydropower should be encouraged to store intermittent renewable energy and further improve grid reliability as we transition to clean electricity sources. With the right policies and planning, hydropower can reclaim its place as a major player in our clean energy future.

Conclusion

As we have seen, hydropower has a long history of providing clean, renewable electricity around the world. With over 1,300 GW of installed capacity globally, it remains the largest source of renewable energy today. While other renewables like solar and wind have seen tremendous growth recently, hydropower’s contributions are often overlooked and underappreciated.

Yet hydropower offers unique advantages that make it an invaluable part of our energy mix. Its storage capabilities allow it to balance grid fluctuations from intermittent renewables. It is still the cheapest source of renewable electricity in many parts of the world. Hydropower facilities can also provide flood control, irrigation, and recreational benefits.

Of course, hydropower faces environmental challenges and competition from other renewables for investment. But with plenty of untapped potential remaining, both large and small hydropower projects will be crucial in the transition to clean energy. Renewed focus and innovation are needed for hydropower to realize its full promise. With the right vision and policies, this forgotten giant can continue powering the world sustainably far into the future.