Environmental Engineering Reference
In-Depth Information
TABLE 3.2
Water Intensity of Electricity Generation by Fuel Source and Technology
a
Water
Consumed
for Cooling
(gal/MWh)
Other Water
Consumed in
Generation
(gal/MWh)
Water
Consumed in
Producing Fuel
(gal/MWh)
Generation Technology
Cooling System
CSP trough or tower (wet-cooled)
b
Closed-loop cooling tower
710-960
40-60
0
CSP trough or tower (dry-cooled)
c
Dry air cooling
0
30-80
0
CSP dish/engine
d
Dry air cooling
0
4-6
0
PV
e
None
0
0-5
0
Windf
f
None
0
0
0
Pulverized coal
f,g
Closed-loop cooling tower
360-590
60-120
5-74
Pulverized coal with CO
2
capture
f,h
Closed-loop cooling tower
700-770
150-180
5-74
Integrated gasification combined cycle (IGCC)f,i
f,i
Closed-loop cooling tower
250-370
40-70
5-74
IGCC with CO
2
capture
f,j
Closed-loop cooling tower
390-410
130-150
5-74
Natural gas combined cycle (CC)
f,k
Closed-loop cooling tower
180-280
2
11
Nuclear
f,l
Closed-loop cooling tower
580-850
30
45-150
Source:
USDOE, SunShot Vision Study, U.S. Department of Energy, Washington, DC, 2012.
a
The table does not account for water consumption in system manufacturing or construction of any of the technologies. Water con-
sumption for fuel extraction is considered for fossil and nuclear. All wet-cooled Rankine power cycles are assumed to use closed-loop
cooling towers with four cycles of concentration and blowdown water discharge to an onsite evaporation pond. Water consumption
values for wet-cooled Rankine power cycles using once-through cooling systems are not shown because their large water withdrawal
requirements make them infeasible for the Southwest. Dry cooling is possible with all Rankine cycles, although it is explicitly shown
for CSP only.
b
From Cohen et al. (1999) and Viebahn et al. (2008). Other water consumed for trough and tower technologies includes water for
washing mirrors and steam-cycle blowdown and makeup. Mirror soiling rates/washing rates are site and developer specific. Towers
will be at the lower end of the cooling-water range and troughs at the higher end due to thermal efficiency differences.
