The 30 Largest Hydropower Plants in the U.S.
Did you know that the largest power plant in the United States is hydroelectric?
Hydropower is the second-largest source of U.S. renewable electricity generation and the largest source of power in seven different states.
The above infographic from the National Public Utilities Council charts the 30 largest U.S. hydropower plants and shows how droughts are starting to affect hydroelectricity. This is part one of two in the Hydropower Series.
Dam, That’s Large: U.S. Hydropower Plants by Generation
The top 30 hydropower plants account for around 50% of U.S. hydroelectric generation annually.
Hydropower plants are most prevalent in the Northwestern states of Washington and Oregon, jointly hosting 16 of the top 30 plants.
|Plant Name||State||2021 Avg. Net Electricity Generation (MWh)||% of Total Hydropower Generation|
|Robert Moses - Niagara||New York||14,186,130||5%|
|Robert Moses - St. Lawrence||New York||6,906,420||3%|
|Hoover Dam - NV||Nevada||2,044,127||0.7%|
|Hoover Dam - AZ||Arizona||1,713,563||0.6%|
The Grand Coulee Dam in Washington is the country’s largest power plant. It generates over 19.5 million megawatt-hours (MWh) of electricity annually and supplies it to eight states, including parts of Canada. Overall, 10 of the top 30 hydropower plants are in Washington.
The Robert Moses Power Plant is a close second, located around 5 miles downstream from Niagara Falls. Combined with the nearby Lewiston Pump Generation Plant, it is New York’s single-largest source of electricity.
While hydropower is a relatively reliable renewable power source, prolonged dry conditions can put it at risk. That is the case for both the Glen Canyon and Hoover Dams, which are no longer running at previous capacities.
Running Dry: Water Scarcity and Hydropower
The Southwestern U.S. has been in a “megadrought”—a prolonged drought lasting longer than two decades—since 2000. In fact, it has gotten so severe that the past 22 years mark the region’s driest spell in 1,200 years.
Consequently, many Southwestern reservoirs have below-average storage levels. When these levels fall below a certain threshold, hydropower plants can no longer generate power.
In particular, storage levels are precariously low at Lake Mead (Hoover Dam) and Lake Powell (Glen Canyon Dam), which supply most of Arizona’s hydroelectricity. They are also the two largest reservoirs in the country.
Here’s a look at how filled these reservoirs are as of Dec. 4, 2022:
|Reservoir||Total Storage (acre ft)||Current Storage (acre ft)||% Full|
|Lake Mead |
(Glen Canyon Dam)
To put those figures into perspective, here’s an animation looking at Lake Powell’s surface area changes from 2018 to 2022:
Shrinking water levels at reservoirs threaten the reliability of hydropower and the millions of people that rely on it for electricity. As droughts become more frequent due to climate change, what does the future of hydropower look like?
Find out in Part 2 of the Hydropower Series, where we’ll dive deeper into how droughts are affecting dams and how hydropower fits into the bigger decarbonization picture.
Mapped: U.S. Wind Electricity Generation by State
Mapping U.S. Wind Energy by State
This was originally published on April 25, 2022, on Elements.
Wind power is the most productive renewable energy source in the U.S., generating nearly half of America’s renewable energy.
But wind doesn’t blow fairly across the nation, so which states are contributing the most to U.S. wind energy generation?
This map uses data from the EIA to show how much wind electricity different U.S. states generate, and breaks down wind’s share of total electricity generation in top wind power producing states.
Wind Electricity Generation by State Compared
America’s wind energy generating states are all primarily located in the Central and Midwest regions of the nation, where wind speeds are highest and most consistent.
Texas is the runaway leader in wind, generating over 92 Terawatt-hours of electricity during a year, more than the next three top states (Iowa, Oklahoma, and Kansas) combined. While Texas is the top generator in terms of wind-powered electricity, wind only makes up 20% of the state’s total electricity generation.
|State||Wind Electricity Generation (Terawatt hours)||Wind's Share of Net Electricity Generation|
|North Dakota||13.2 TWh||31%|
Data from Feb 2020-Feb 2021
Meanwhile, wind makes up a much larger share of net electricity generation in states like Iowa (58%), Oklahoma (35%), and Kansas (43%). For both Iowa and Kansas, wind is the primary energy source of in-state electricity generation after overtaking coal in 2019.
The U.S. also has 10 states with no wind power generating facilities, all primarily located in the Southeast region.
How Does Wind Energy Work?
Humans have been harnessing wind power for millennia, with windmills originally relying on wind to pump water or mill flour.
Today’s wind turbines work similarly, with their large blades generating electricity as wind causes them to rotate. As these blades are pushed by the wind, a connected internal shaft that is attached to an electric generator also turns and generates electricity.
Wind power is one of the safest sources of energy and relies on one key factor: wind speeds. When analyzing minimum wind speeds for economic viability in a given location, the following annual average wind speeds are needed:
- Small wind turbines: Minimum of 4 meters per second (9 miles per hour)
- Utility-scale wind turbines: Minimum of 5.8 meters per second (13 miles per hour)
Unsurprisingly, the majority of America’s onshore wind turbine infrastructure is located in the middle of the nation, where wind speeds are highest.
Growing America’s Wind Turbine Capacity
While wind energy only made up 0.2% of U.S. electricity generating capacity in 1990, it is now essential for the clean energy transition. Today, wind power makes up more than 10% of U.S. electricity generating capacity, and this share is set to continue growing.
Record-breaking wind turbine installations in 2020 and 2021, primarily in the Central and Midwest regions, have increased U.S. wind energy generation by 30% to 135.1 GW.
In 2020, the U.S. increased wind turbine capacity by 14.2 gigawatts, followed by another 17.1 gigawatts in 2021. This year is set to see another 7.6 GW come online, with around half of 2022’s added capacity located in Texas.
After two years of record-breaking wind turbine installations, 2021’s expiration of the U.S. production tax credit is likely to dampen the rate of future installations.
What Are the Five Major Types of Renewable Energy?
Renewable energy is the foundation of the ongoing energy transition. What are the key types of renewable energy, and how do they work?
The Renewable Energy Age
This was originally published on June 8, 2022, on Elements.
Awareness around climate change is shaping the future of the global economy in several ways.
Governments are planning how to reduce emissions, investors are scrutinizing companies’ environmental performance, and consumers are becoming conscious of their carbon footprints. But no matter the stakeholder, energy generation and consumption from fossil fuels is one of the biggest contributors to emissions.
Therefore, renewable energy sources have never been more top-of-mind than they are today.
The Five Types of Renewable Energy
Renewable energy technologies harness the power of the sun, wind, and heat from the Earth’s core, and then transforms it into usable forms of energy like heat, electricity, and fuel.
|Energy Source||% of 2021 Global Electricity Generation||Avg. levelized cost of energy per MWh|
Editor’s note: We have excluded nuclear from the mix here, because although it is often defined as a sustainable energy source, it is not technically renewable (i.e. there are finite amounts of uranium).
Though often out of the limelight, hydro is the largest renewable electricity source, followed by wind and then solar.
Together, the five main sources combined for roughly 28% of global electricity generation in 2021, with wind and solar collectively breaking the 10% share barrier for the first time.
The levelized cost of energy (LCOE) measures the lifetime costs of a new utility-scale plant divided by total electricity generation. The LCOE of solar and wind is almost one-fifth that of coal ($167/MWh), meaning that new solar and wind plants are now much cheaper to build and operate than new coal plants over a longer time horizon.
With this in mind, here’s a closer look at the five types of renewable energy and how they work.
Wind turbines use large rotor blades, mounted at tall heights on both land and sea, to capture the kinetic energy created by wind.
When wind flows across the blade, the air pressure on one side of the blade decreases, pulling it down with a force described as the lift. The difference in air pressure across the two sides causes the blades to rotate, spinning the rotor.
The rotor is connected to a turbine generator, which spins to convert the wind’s kinetic energy into electricity.
2. Solar (Photovoltaic)
Solar technologies capture light or electromagnetic radiation from the sun and convert it into electricity.
Photovoltaic (PV) solar cells contain a semiconductor wafer, positive on one side and negative on the other, forming an electric field. When light hits the cell, the semiconductor absorbs the sunlight and transfers the energy in the form of electrons. These electrons are captured by the electric field in the form of an electric current.
A solar system’s ability to generate electricity depends on the semiconductor material, along with environmental conditions like heat, dirt, and shade.
Geothermal energy originates straight from the Earth’s core—heat from the core boils underground reservoirs of water, known as geothermal resources.
Geothermal plants typically use wells to pump hot water from geothermal resources and convert it into steam for a turbine generator. The extracted water and steam can then be reinjected, making it a renewable energy source.
Similar to wind turbines, hydropower plants channel the kinetic energy from flowing water into electricity by using a turbine generator.
Hydro plants are typically situated near bodies of water and use diversion structures like dams to change the flow of water. Power generation depends on the volume and change in elevation or head of the flowing water.
Greater water volumes and higher heads produce more energy and electricity, and vice versa.
Humans have likely used energy from biomass or bioenergy for heat ever since our ancestors learned how to build fires.
Biomass—organic material like wood, dry leaves, and agricultural waste—is typically burned but considered renewable because it can be regrown or replenished. Burning biomass in a boiler produces high-pressure steam, which rotates a turbine generator to produce electricity.
Biomass is also converted into liquid or gaseous fuels for transportation. However, emissions from biomass vary with the material combusted and are often higher than other clean sources.
When Will Renewable Energy Take Over?
Despite the recent growth of renewables, fossil fuels still dominate the global energy mix.
Most countries are in the early stages of the energy transition, and only a handful get significant portions of their electricity from clean sources. However, the ongoing decade might see even more growth than recent record-breaking years.
The IEA forecasts that, by 2026, global renewable electricity capacity is set to grow by 60% from 2020 levels to over 4,800 gigawatts—equal to the current power output of fossil fuels and nuclear combined. So, regardless of when renewables will take over, it’s clear that the global energy economy will continue changing.
Electrification3 months ago
Visualized: How the Power Grid Works
Emissions3 months ago
Visualizing Global Per Capita CO2 Emissions
Climate2 months ago
Visualizing the State of Climate Change
Electrification3 months ago
Road to Decarbonization: The United States Electricity Mix
Climate3 months ago
Mapped: 30 Years of Deforestation and Forest Growth, by Country
Decarbonization3 months ago
The U.S. Utilities Decarbonization Index
Energy3 months ago
Ranked: Emissions per Capita of the Top 30 U.S. Investor-Owned Utilities
Clean Energy3 months ago
Mapped: U.S. Wind Electricity Generation by State