WSHPDR_2013_Final_Report-updated_version

2.4.2 United States of America
Lara Esser, International Center on Small Hydro Power
Key facts
Population 313,847,465 1
Area 9,826,675 km²
Climate Mostly temperate, but tropical in
Hawaii and Florida, arctic in Alaska,
semi-arid in the great plains west of
the Mississippi River, and arid in the
Great Basin of the southwest; low
winter temperatures in the
northwest 1
Topography Vast central plain, mountains in west,
hills and low mountains in east.
Rugged mountains and broad river
valleys in Alaska. Rugged, volcanic
topography in Hawaii (Highest point:
Mount McKinley, 6,194 m) 1
Rain pattern Variable, depending on location and
elevation
Electricity sector overview
In 2011, the installed power generating capacity in the
United States of America (USA) was 1,138 GW, and its
net electricity generation surpassed 4,100 TWh. 2
Fossil fuels and nuclear power account for 87 per cent
of electricity generation in the USA (figure 1).
According to the International Energy Agency (IEA), in
2009 the USA was the world’s largest producer of
nuclear power (830 TWh), and of electricity from
natural gas (950 TWh). 3 It was also the world’s second
largest electricity producer from coal (1,893 TWh),
and it accounts for the second largest hydropower
capacity at 100 GW. 2 0.04%
0.37%
0.48%
0.74%
1.38%
2.93%
7.79%
19.27%
Solar
Geothermal
Other
Petroleum (liquids and coke)
Biomass
Wind
Conventional hydroelectric
Nuclear
Natural gas
Coal
24.72%
42.27%
0% 10% 20% 30% 40% 50%
Figure 1 Electricity generation in United States
Source: DSIRE 2
Note: Data from 2011.
An interim assessment of technically feasible
hydropower potential by the U.S. Department of
Energy (DOE) identified 372 GW undeveloped
hydropower resources, divided between upgrades,
retrofits, new projects, and pumped storage. The DOE
Water Power Programme has set a goal of increasing
U.S. hydropower capacity by 100 GW before 2050. 5
213
Small hydropower sector overview and potential
The definition of small hydropower in the USA varies
from state to state. It ranges from a capacity of 5 MW
to a capacity of 100 MW. Currently, 92 per cent of
existing turbines in the USA are classified as small or
low power. These types of plants account for 20 per
cent of the existing hydropower generation capacity,
but they are part of a much larger proportion of the
country’s under-developed potential. 5 The installed
capacity of hydropower plants up to 10 MW can only
be estimated (table 1, figure 2)
SHP installed
capacity
SHP potential
6785 MW
8041 MW
0 2000 4000 6000 8000 10000
Figure 2 Small hydropower capacities in the United
States of America
Source: Author’s calculations, U.S. Department of the
Interior, Bureau of Reclamation, Power Resources
Office 9 , Department of Energy 11
Note: Data provided for plants up to 10 MW.
Small hydropower presents a significant opportunity
for increased electricity generation in the USA. Several
studies assessing the US small hydropower potential
have been carried out, with varying results. The
Electric Power Research Institute (EPRI) estimates that
by 2025, some 2,700 MW could come from new smalland
low-power hydropower projects, and a further
3,000 MW could be developed from in-stream
hydro-kinetic projects. 7 i
An assessment by Idaho National Lab (INL) (2006) on
the potential for development of small- and low-head
hydropower generation in the USA identified around
5,400 of 100,000 sites. Small hydropower is defined as
providing between 1 and 30 MW of annual mean
power, while low-head hydropower usually refers to
sites with a head i.e. elevation difference of less than
five meters. 7
A pilot study by the INL for the Northwest Region (i.e.
Idaho, Oregon and Washington State), developed and
demonstrated a methodology capable of
comprehensively modeling sites in a large region using
a stream-obstructing dam development model 8 The
result shows 5,439 stream reaches with 15,140 MW
total potential in the Northwest Region (small hydro
definition of 1-50 MW). The candidate stream reaches
are not located in the exclusion zones and have site
characteristics within technically reasonable limits,
however further detailed assessment of individual
sites will be required to determine technical and
economic feasibility. 8