HYDROPOWER

HYDROPOWER

HYDROPOWER

Hydropower, in which the power of moving water – rivers, streams and ocean tides – generates electricity, is the provider of 16% of the world’s electricity and 7% of America’s. Until 2019, it was America's largest source of clean, renewable electricity — when wind surpassed it — generating power in all but two states and accounting for 52% of the nation's renewable electricity generation.

Most hydroelectricity is produced at large dams (called Impoundment Facilities) built by the federal government, and many of the largest hydropower dams are in the western United States, the majority in California, Washington and Oregon. The oldest dates back to 1882, when the world’s first hydroelectric power plant began operating in the United States along the Fox River in Appleton, Wisconsin. The biggest is the Grand Coulee Dam on the Columbia River in Washington, a state that gets about two-thirds of its electricity from hydropower. New York has more capacity than other states east of the Mississippi, followed by Alabama.

A typical hydroelectric plant is a system with three parts: a power plant where the electricity is produced, a dam that can be opened or closed to control water flow, and a reservoir where water is stored. The water behind the dam flows through an intake and pushes against blades in a turbine, causing them to turn. The turbine spins a generator to produce electricity (the amount of electricity that can be generated depends on how far the water drops and how much water moves through the system). It then gets transported through long-distance electric lines to homes, factories, and businesses.

There are other types of hydropower plants, which make use of the flow through a waterway without a dam (called Diversion Facilities) and Pumped Storage. Eighteen states have pumped-storage hydroelectric plants. These generate electric energy during peak load periods by using water previously pumped into an elevated storage reservoir during off-peak periods when excess generating capacity is available to do so. As additional generating capacity is needed, the water can be released from the reservoir through a conduit to turbine generators located in a power plant at a lower level.

Hydropower has significant advantages. Once a dam has been built and the equipment installed, the energy source — flowing water — is free and essentially clean, an energy source renewed by snow and rainfall. Hydropower plants can supply large amounts of electricity, and they are relatively easy to adjust for demand by controlling the flow of water through the turbines.

But there are some disadvantages, too. A dam that creates a reservoir, for example, may obstruct fish migration and affect the ecology of the river, having negative effects on native plants or animals, not to mention people who might have to be relocated. The manufacturing materials, particularly cement, needed also pose a problem because of the carbon emissions associated. And dam failure can be both disastrous and deadly.

Furthermore, the promise of carbon-free electricity from hydropower has been undermined by revelations that decaying organic material in reservoirs releases methane, a potent greenhouse gas that contributes to global warming.

As the controversy continues, global warming, the very condition hydropower wants to combat, has also become its adversary as drought dries up water sources.

Research continues on ways to make hydropower projects more friendly to the ecosystems around them. In some places, small hydro projects can take advantage of existing water flows or infrastructure. Special water intakes and turbines can help make sure the water released from the dam is better aerated to address the problem of low dissolved oxygen. Dams can be planned more strategically to allow fish passages, for example, while water flows at existing dams can be calibrated to give ecosystems more recovery time from flooding cycles.

Tidal and wave power are also being explored. Tidal turbines look similar to wind turbines. They can be placed on the sea floor where there is strong tidal flow. Because water is about 800 times denser than air, tidal turbines have to be much sturdier and heavier than wind turbines. Tidal turbines are more expensive to build than wind turbines but capture more energy with the same size blades. A demonstration tidal turbine project is planned for deployment into the East River of New York in the autumn of 2020.

Ocean waves also contain tremendous energy. It is estimated that harnessing just two one-thousandths of the oceans’ untapped energy could provide power equal to current worldwide demand.

Then there is ocean thermal energy (OTEC), a process or technology for producing energy by harnessing the temperature differences (thermal gradients) between ocean surface waters and deep ocean waters.

The United States became involved in OTEC research in 1974 with the establishment of the Natural Energy Laboratory of Hawaii Authority. The laboratory is one of the world's leading test facilities for OTEC technology. The laboratory operated a 250-kilowatt (kW) demonstration OTEC plant for six years in the 1990s. The United States Navy supported the development of a 105 kW demonstration OTEC plant at the laboratory site. This facility became operational in 2015 and supplies electricity to the local electricity grid.

The Department of Energy estimates there are nearly 50 gigawatts of untapped hydropower potential, according to the 2020 Hydropower Status Report, and that the existing infrastructure provides reliable electricity amid intermittent renewables like solar and wind.

CURRENT NEWS

KEY RESOURCES

The Champlain Hudson Power Express (Chpe) Project

10/08/20
The Champlain Hudson Power Express Project is a 333-mile, buried transmission line that will bring up to 1,000 megawatts (mw) of clean, renewable energy to the New York City metropolitan area. 1,000 mw is enough…

Environmental Impacts of Hydroelectric Power

06/26/20
Hydroelectric power includes both massive hydroelectric dams and small run-of-the-river plants. Large-scale hydroelectric dams continue to be built in many parts of the world (including China and Brazil), but it is unlikely that new facilities…

How Hydroelectric Energy Works

06/26/20
By taking advantage of gravity and the water cycle, we have tapped into one of nature's engines to create a useful form of energy. In fact, humans have been capturing the energy of moving water…

Hydropower

04/14/20
Hydropower is energy derived from flowing water. More than 2,000 years ago, the ancient Greeks used waterpower to run wheels for grinding grain; today it is among the most cost-effective means of generating electricity and…

Hydropower, explained

04/10/20
Humans have been harnessing the energy of river currents for centuries, using water wheels spun by rivers initially to process grains and cloth. Today, hydropower provides about 16 percent of the world's electricity, generating power…

Hydroelectric Power: How it Works

04/10/20
So just how do we get electricity from water? Actually, hydroelectric and coal-fired power plants produce electricity in a similar way. In both cases a power source is used to turn a propeller-like piece called…

TYPES OF HYDROPOWER

04/10/20
To be sure, each megawatt of power we add would have a positive impact on the communities we serve – leading to a healthier America. For example, 50 by 2050 means nearly 5 million fewer…

Benefits of Hydropower

04/10/20
Hydropower is fueled by water, so it's a clean fuel source, meaning it won't pollute the air like power plants that burn fossil fuels, such as coal or natural gas.

Hydropower is energy in moving water

04/10/20
People have a long history of using the force of water flowing in streams and rivers to produce mechanical energy. Hydropower was one of the first sources of energy used for electricity generation and and…

International Hydropower Association

12/16/18
Our mission is to advance sustainable hydropower by building and sharing knowledge on its role in renewable energy systems, responsible freshwater management and climate change solutions. We recognise that the world is changing, and a…

MORE NEWS

Global resource potential of seasonal pumped hydropower storage for energy and water storage

By Julian D. Hunt and Yoshihide Wada   02/19/20  
Seasonal mismatches between electricity supply and demand is increasing due to expanded use of wind, solar and hydropower resources, which in turn raises the interest on low-cost seasonal energy storage options.

Energy Department Renews Commitment to Collaboration on Hydropower Research and Development with Norway

02/12/20  
Last week the U.S. Department of Energy (DOE) and Norway’s Royal Ministry of Petroleum and Energy (OED) made a commitment to collaborate on hydropower research and development by signing an Annex to a previously signed…

America’s ‘First’ Renewable Resource Overlooked as States Embrace Clean Energy

By Malcolm Woolf   01/31/20  
As laboratories of democracy, states deserve a victory lap for enacting renewable portfolio standards that have helped transform our electricity system. But as the original purposes of these laws have been largely achieved, states can…
cnn

The green power source that can do more harm than good

By Paul Hockenos   01/21/20  
Climate change is already wreaking lethal havoc on the world of flora and fauna. So, all hands on deck to save the planet, right? We're behind in the chase and need all the clean energy…

Moving To The System Scale Can Improve Hydropower

By Jeff Opperman  Photo by De Agostini   01/14/20  
Hydropower is the world’s leading source of renewable energy and most hydropower projects generate low-carbon electricity. Yet—as highlighted in a recent op-ed in CNN—hydropower is rarely placed in the bin of virtuous renewables alongside wind…

Dammed Good Questions about the Green New Deal

By Don Fitz   11/27/19  
Hydroelectric power from dams might be the thorniest issue that proponents of the Green New Deal (GND) have to grapple with. Providing more energy than solar and wind combined, dams could well become the key…

How hydroelectricity will help power Asia’s future in 21st century

By M Joseph  Photo by Getty Images   11/26/19  
It’s tempting to imagine hydropower as a relatively modern phenomenon – born in the 1950s and really taking root only in the 21st century.

Department of Energy Challenges Innovators to Harness the Power of the Oceans

11/14/19  
Today, the U.S. Department of Energy (DOE) announced developments in two new prizes: Waves to Water, which challenges innovators to desalinate water using the power of ocean waves, and the Powering the Blue Economy™ Ocean…

Climate impact of hydropower varies widely

11/13/19  
Hydropower is broadly considered to be much more environmentally friendly than electricity generated from fossil fuels, and in many cases this is true. However, a new study reveals that the climate impact of hydropower facilities…

DOE Announces US$24.9 Million Funding Selections to Advance Hydropower

11/06/19  
Projects were selected across four areas of interest — hydropower operational flexibility, low-head hydropower and in-stream hydrokinetic technologies, advancing wave energy device design, marine energy centers research infrastructure upgrades.

Analysis of emerging technologies in the hydropower sector

By Ioannis Kougias George Aggidis   10/01/19  
The paper reviews recent research and development activities in the field of hydropower technology. It covers emerging and advanced technologies to mitigate flow instabilities (active and passive approach) as well as emerging magneto-rheological control techniques.…

The Interior Secretary Wants to Enlarge a Dam. An Old Lobbying Client Would Benefit.

By Coral Davenport   09/28/19  
The project is going forward now, in a big win for a powerful consortium of California farmers that stands to profit substantially by gaining access to more irrigation water from a higher dam and has…

Montana Developer Ready to Build Modern-Day Pumped Hydro Storage

By Julian Spector   08/13/19  
A former Navy prosecutor turned Montana-based clean energy developer wants to build the first pumped hydro storage facility the U.S. has seen in years. Battery installations are growing at a steady clip, but good old…

US Wind To Exceed Hydropower In 2019 For First Time

By Joshua S Hill   01/16/19  
The latest energy and electricity forecasts from the US government has predicted that wind energy will outperform hydropower for the first time, providing a greater share of the country’s electricity mix in 2019.

Los Angeles Wants To Use The Hoover Dam As A Giant Battery

By Anthony F. Arrigo   08/29/18  
Los Angeles is looking into whether it should spend an estimated US$3 billion on a massive, 20-mile underground pumped hydropower storage system that would be connected to the iconic Hoover Dam on the Colorado River…

The Costs and Benefits of Hydropower

By Lois Parshley  Photo by Sean McDermott   01/05/18  
On an early spring evening in southwestern Albania, Taulant Hazizaj walks between silver-gray olive trees near the Vjosa River. Farms sprawl over the wide river valley, swatches of irrigated green giving way to the rocky…