Cost and Performance 

Baseline for Fossil Energy 

Plants

Volume 1: Bituminous Coal 

and Natural Gas to Electricity

Revision 2a, September 2013

Revision 2, November 2010

DOE/NETL-2010/1397
Cost and Performance Baseline for Fossil Energy Plants

Water Use

Three water values are presented for each technology in Exhibit ES-4: raw water withdrawal, 

process discharge, and raw water consumption. Each value is normalized by net output. Raw 

water withdrawal is the difference between demand and internal recycle. Demand is the amount 

of water required to satisfy a particular process (slurry, quench, flue gas desulfurization [FGD]

makeup, etc.) and internal recycle is water available within the process (boiler feedwater [BFW] 

blowdown, condensate, etc.). Raw water withdrawal is the water removed from the ground or 

diverted from a surface-water source for use in the plant. Raw water consumption is the portion 

of the raw water withdrawn that is evaporated, transpired, incorporated into products or 

otherwise not returned to the water source it was withdrawn from. Raw water consumption is 

the difference between withdrawal and process discharge, and it represents the overall impact of 

the process on the water source, which in this study is considered to be 50 percent from 

groundwater (wells) and 50 percent from a municipal source. All plants are equipped with 

evaporative cooling towers, and all process blowdown streams are assumed to be treated and 

recycled to the cooling tower. The primary conclusions that can be drawn are:

• In all cases the primary water consumer is cooling tower makeup, which ranges from 

73 to 99 percent of the total raw water consumption.

• Among non-capture cases, NGCC requires the least amount of raw water withdrawal, 

followed by IGCC and PC. If an average raw water consumption for the three IGCC 

cases and two PC cases is used, the relative normalized raw water consumption for 

the technologies is 2.5:1.7:1.0 (PC:IGCC:NGCC). The relative results are as 

expected given the much higher steam turbine output in the PC cases, which results in 

higher condenser duties, higher cooling water flows, and ultimately higher cooling 

water makeup. The IGCC cases and the NGCC case have comparable steam turbine 

outputs, but IGCC requires additional water for coal slurry (GEE and CoP), syngas 

quench (GEE), humidification (CoP and Shell), gasifier steam (Shell), and slag 

handling (all cases), which increases the IGCC water withdrawal over NGCC.

• Among capture cases, raw water withdrawal requirements increase (relative to noncapture cases) more dramatically for the PC and NGCC cases than for IGCC cases 

because of the large cooling water demand of the Econamine process, which results in 

greater cooling water makeup requirements. If average water consumption values are 

used for IGCC and PC cases, the relative normalized raw water consumption for the 

technologies in CO2 capture cases is 2.4:1.4:1.0 (PC:IGCC:NGCC). The NGCC CO2

capture case still has the lowest water consumption.

• CO2 capture increases the average raw water consumption for all three technologies 

evaluated, but the increase is lowest for the IGCC cases. The average normalized raw 

water consumption for the three IGCC cases increases by about 58 percent due 

primarily to the need for additional water in the syngas to accomplish the WGS 

reaction. With the addition of CO2 capture, PC normalized raw water consumption

increases by 83 percent and NGCC by 91 percent. The large cooling water demand 

of the Econamine process drives this substantial increase for PC and NGCC.

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