A typical hydropower system passes water through turbines
connected to generators that create electricity as they rotate. The amount of
energy that can be produced depends upon water flow, volume, and pressure. Hydropower
is an efficient way to create electricity and has relatively low operating
costs. Many hydro generators can ramp
up or down quickly, so they can be nimble to current electricity
The complex system of dams and
reservoirs that form the Federal Columbia River Power System has been a key
component of economic growth, equitable access to electricity, and a clean
power ethic in the Northwest.
In a 1932 campaign speech, Franklin
Roosevelt promised that the next great federal hydroelectric project would be
built on the Columbia River. The U.S. government built the Bonneville and Grand
Coulee dams in the 1930s and 1940s. Power from these massive projects
strengthened the Northwest economy and brought electricity to rural areas that
were not served by existing utilities.
Congress created the Bonneville Power Administration (BPA) in 1937 to deliver
and sell power from Bonneville Dam. The first line connected Bonneville Dam to
Cascade Locks, just three miles from the dam. Major construction from the 1940s
through the 1960s created a transmission system touching most parts of BPA's
service territory. During that time, Congress authorized BPA to sell and
deliver power from more federal dams on the Columbia and its tributaries.
The Federal Columbia River Power System now includes 31 hydroelectric projects with a capacity to
deliver more than 22,000 megawatts of power. The dams are operated by the U.S. Army
Corps of Engineers and the Bureau of Reclamation, and BPA markets the power
from the system.
Low-cost Columbia River hydropower is a cornerstone of the
Northwest economy. About 28 percent of the power consumed in the Pacific
Northwest comes from the BPA. Northwest utilities and a few large industries buy
BPA power; utilities resell it to homes, businesses, and other consumers.
Oregon is the second highest hydropower-producing state in the nation, behind only Washington. (U.S. Energy Information Administration, February 2016)
Learn more about energy in Oregon in our Biennial Energy Report.
Oregon and Hydropower
Oregon has 34 consumer-owned
utilities that rely on the BPA for all or a majority of their power. These utilities include electric cooperatives, public utility
districts, and municipal utilities. Many of the
smaller BPA customer utilities count on the BPA for 100 percent of the power they
sell to customers and these utilities have some of the lowest retail power
rates in the country.
The BPA is not the only entity to
sell power from large hydroelectric facilities. Portland General Electric and the
Eugene Water and Electric Board are two examples of Oregon utilities that own
and operate hydro facilities and deliver that power to their customers and the wholesale market.
Low-cost and carbon-free hydropower
is attractive to new industries that use a lot of power, such as data centers, that
want to locate in Oregon.
Types of Hydro Projects
Common types of hydropower facilities:
- Impoundments block river flow and selectively release water stored in a reservoir. They are the most common type of hydropower plant.
- Diversion facilities use intakes to withdraw water from the river without a reservoir.
- Pumped storage facilities move water between two reservoirs by releasing water from an upper reservoir to a lower reservoir to generate electricity during periods of high power demand. During low demand, the water is pumped from the lower reservoir back to the upper reservoir.
- Conduit projects usually incorporate small turbines into existing infrastructure such as tunnels, pipelines, and canals to generate electricity from flowing water.
Impoundment hydropower facilities can have negative impacts on the environment, including interruptions to migratory patterns of fish and other animals; methane off-gassing from reservoirs; and reduced downstream flows and resultant changes in stream temperature, oxygen levels, and habitat.
Because conduit projects avoid the impacts to natural resources associated with other kinds of hydro projects, many new technologies focus on conduit designed for irrigation canals, municipal pipes, and other types of artificial water conveyance structures. Examples in Oregon include Natel Energy’s project for the North Unit Irrigation District at a Bureau of Reclamation facility near Madras and Lucid Energy’s installation in the City of Portland’s water pipes.
Balancing Renewable Energy
resources such as wind and solar are variable over the course of a day and from
season to season, because the sun doesn’t always shine and the wind doesn’t
always blow. Integrating renewable energy can be a challenge for grid operators
to keep the supply and demand for electricity in balance.
By increasing or
decreasing the amount of water flowing through the generators, the BPA's hydro
system has provided much of the necessary balancing service. Currently BPA
provides approximately 1,000 megawatts of system flexibility to the region to
balance generation and load (demand). However, hydro facilities are increasingly
constrained by restrictions related to allowed spillover or drawn-down
reservoirs due to environmental concerns, tribal agreements, and recreation and
transportation uses. In addition, hydropower is becoming less reliable due to
changes associated with climate change, such as extreme weather events, reduced
snowpack, high or low spring runoff volumes, and droughts.
With the potential for
greater uncertainty in the availability of hydropower to meet load shortfalls
based on seasonal and climate-related variability, the region is looking at more options for balancing generation and demand.
Hydro Energy Storage
affordable, utility-scale grid option for energy storage is pumped storage, which stores energy by pumping water uphill during
times of low electricity demand. When demand for electricity is high, the
stored water can be released to flow downhill and generate electricity. The downsides of pumped
storage include a high relative cost and an incompatibility
with many restrictions for Columbia River Basin hydropower operation, such as
flow requirements and fish protections.
Currently there are no pumped storage projects in Oregon.