Energy and Human Ambitions on a Finite Planet, 2021a

11 Hydroelectric <strong>Energy</strong> 179
0 2 4 6 8 10
Hydro generation (GW)
Figure 11.5: Average U.S. hydroelectric
power delivered for each state, showing
strongly along the west-coast, plus New
York. And yes, Alaska really is that big.
1.25 × 10 14 m 2 , so that a total hydroelectric potential of 2.5 TW 24 would 24: This is higher than estimated potential
yield 0.02 W/m 2 . Therefore, the state of Washington st<strong>and</strong>s out as developed resources, but mathematically
convenient here.
unusual, having already developed a generation capacity 2.5 times larger
than the upper-end global average expectation. In other words, most of
the world cannot emulate what nature has provided in Washington. 25
Not all places have the same available resources.
25: Washington’s hydroelectric dominance
owes largely to the presence of the mighty
Columbia River, rather than human factors.
0 10 20 30 40 50
Hydro density (mW/m 2 )
Figure 11.6: U.S. hydroelectric power per
area delivered for each state, giving a sense
of how concentrated the resource is. The
units are milliwatts per square meter, peaking
at 48 mW/m 2 for Washington.
Next, we look at hydroelectric generation per capita. Figure 11.7 shows
the result. In this view, the states of the Pacific Northwest really pop
up, <strong>and</strong> New York dims relative to its by-area showing. The contrast
between Figure 11.6 <strong>and</strong> Figure 11.7 is effectively reflecting population
density: large, sparsely-populated states 26 show up more prominently
on the per-capita map than the per-area map.
Finally, for completeness, we look at the capacity factors of hydroelectric
installations, by state. The total installed capacity in the database used
for these plots is 77.6 GW spread among 1,317 dams, while producing an
annual average of 28.1 GW—corresponding to an overall capacity factor of
0.36. Figure 11.8 shows how this distributes around the country. Since the
Pacific Northwest dominates in installed hydroelectric power, it largely
determines the overall capacity factor. Iowa st<strong>and</strong>s out as having a high
capacity factor, but only has 0.153 GW of installed capacity. 27 Contrast
this to Washington, having an installation capacity of 20.7 GW. 28
26: Montana, Idaho, even Alaska
27: . . . delivering an average of 0.114 GW in
8 dams, dominated by the 0.125 GW Keokuk
dam
28: . . . delivering an average of 8.9 GW
spread across 65 dams
© 2021 T. W. Murphy, Jr.; Creative Commons Attribution-NonCommercial 4.0 International Lic.;
Freely available at: https://escholarship.org/uc/energy_ambitions.