Joint GCAM Community Modeling Meeting and GTSP Technical Workshop Joint Global Change Research Institute College Park, Maryland, USA

The Impact of Emissions Mitigation on Water Demand for Electricity Generation PAGE KYLE, EVAN DAVIES, JAMES DOOLEY, STEVE SMITH, MOHAMAD HEJAZI, JAE EDMONDS, AND LEON CLARKE

September 20, 2012

Motivation

!   The electric sector accounts for about 40% of present-day water withdrawals in the US, and is projected to grow substantially in all regions over the next century !   Could be important for resolving

basin-level water supplies and demands

!   The water demands are dependent on the generation technology !   Contributes to uncertainty in the

magnitude of the future water draw from this sector

!   Creates a natural link with the electricity system in GCAM

Region  

Total  Industrial  Withdrawals  (km3/yr)  

Electric  Sector  Withdrawals  (km3/yr)  

USA   220   207  Canada   31   28  Western  Europe   110   96  Japan   16   5  Australia_NZ   3   6  Former  Soviet  Union   79   66  China   133   72  Middle  East   5   3  Africa   11   8  LaIn  America   32   10  Southeast  Asia   46   10  Eastern  Europe   30   23  Korea   3   2  India   35   31  Global  total   753   568  

A Brief Review of Cooling System Types

!   Water is required at power plants for !   Re-condensing steam from the boiler !   Boiler feed water make-up !   Flue gas de-sulfurization !   Other uses

!   Three basic methods of re-condensing steam, which differ in the primary mechanism of heat displacement

System  type  

Mechanism  of  Heat  

Displacement  Cost  ($/kW)  

Withdrawal  Intensity  (m3/MWh)  

ConsumpKon  Intensity  (m3/

MWh)  Once-‐through  flow  

Increase  in  water  temperature   19   150   1  

EvaporaIve  (recirculaIng)  

EvaporaIon  of  water   28   4   2.5  

Dry  cooling   Dissipated  to  air   182   0.3   0.3  

Specific Coefficients Used

Technology   Cooling  system   Water  Withdrawals   Water  ConsumpKon  

Coal  

1-‐thru   158   0.95  Evp   3.8   2.6  Pond   53.2   2.06  

1-‐thru  w/CCS   241   1.25  Evp  w/  CCS   4.83   3.57  

Oil  /  Natural  gas  1-‐thru   152   0.91  Evp   4.55   3.13  Pond   4.55   3.13  

Other  Steam  1-‐thru   152   1.14  Evp   3.32   2.09  Pond   1.7   1.48  

Nuclear  1-‐thru   193   1.02  Evp   4.17   2.54  Pond   30.7   2.31  

Natural  gas  combined  cycle  

1-‐thru   49.5   0.38  Evp   0.96   0.75  Pond   25.9   0.91  

1-‐thru  w/CCS   62.5   0.66  Evp  w/  CCS   1.88   1.43  

IGCC  

1-‐thru   147   0.13  Evp   1.48   1.41  

1-‐thru  w/CCS   186   0.41  Evp  w/  CCS   2.22   2.04  

Geothermal  (convenKonal)  

Evp   6.82   6.82  Hybrid/Dry   0.67   0.67  

EGS  Evp   18.1   18.1  

Hybrid/Dry   3.2   3.2  

CSP  Evp   3.35   3.35  

Hybrid/Dry   0.3   0.3  PV   n/a   0.02   0.02  

Wind   n/a   0   0  Hydro   n/a   0   17  

!   Cooling ponds function in similar fashion to once-through flow OR evaporative cooling (depends on the specific plant configuration)

!   Hybrids generally function as dry cooling but use some evaporative cooling (e.g. during times with high temperature)

Modeling the Electric Sector’s Water Demands in GCAM

!   The current version of GCAM does not have water markets, so there is no technology competition between the different cooling system types

!   For this reason, we assume the different shares of cooling systems that will be deployed for each power plant type and each region in future periods

Cooling  system  type  

Region   Power  Plant  Type   Time  period  Once-‐Through  

Flow  *  Of  which  Saline  

EvaporaKve  Cooling   Cooling  Pond   Dry  

USA   Coal   Base  year   39%   30%   48%   13%   0%  USA   Fossil,  non-‐coal   Base  year   59%   30%   24%   17%   0%  USA   Combined  cycle   Base  year   12%   30%   77%   2%   10%  USA   Nuclear   Base  year   38%   30%   44%   18%   0%  USA   Geothermal   Base  year   0%   0%   60%   0%   40%  USA   IGCC/CCS   Base  year   n/a   n/a   n/a   n/a   n/a  USA   CSP   Base  year   n/a   n/a   n/a   n/a   n/a  USA   Coal   Future  periods   5%   5%   80%   10%   5%  USA   Fossil,  non-‐coal   Future  periods   5%   5%   80%   10%   5%  USA   Combined  cycle   Future  periods   5%   5%   33%   2%   60%  USA   Nuclear   Future  periods   5%   5%   85%   10%   0%  USA   Geothermal   Future  periods   0%   0%   60%   0%   40%  USA   IGCC/CCS   Future  periods   5%   5%   90%   0%   5%  

Scenarios in this Analysis

Scenario   Technology  Strategy   Climate  Policy  NucCCS   Nuclear  and  CCS   None  RE   Renewables   None  NucCCS_4.5   Nuclear  and  CCS   4.5  W/m2  RE_4.5   Renewables   4.5  W/m2  NucCCS_3.7   Nuclear  and  CCS   3.7  W/m2  RE_3.7   Renewables   3.7  W/m2  

0  

1  

2  

3  

4  

5  

6  

7  

8  

2000   2020   2040   2060   2080   2100   2120  

W/m

2  

NucCCS  

RE  

NucCCS_4.5  

RE_4.5  

NucCCS_3.7  

RE_3.7  

Global Electricity Generation by Scenario

0  

100  

200  

300  

400  

500  

2000   2020   2040   2060   2080   2100  

EJ/yr  

NucCCS   NucCCS_4.5   NucCCS_3.7  

RE   RE_4.5   RE_3.7  

0%  10%  20%  30%  40%  50%  60%  70%  80%  90%  

100%  

Developed   Reforming   Developing  

!   Five- to seven-fold expansion in all scenarios !   Developing economies account for greater than 70% of electricity by the

end of the century !   By 2050, 85% of electricity is produced at facilities that did not exist in

2005 !   Climate mitigation policy leads the electricity sector to expand by up to

25%

Electricity Generation by Technology

0%  

10%  

20%  

30%  

40%  

50%  

60%  

70%  

80%  

90%  

100%  

2005  

2015  

2025  

2035  

2045  

2055  

2065  

2075  

2085  

2095  

NucCCS  

0%  

10%  

20%  

30%  

40%  

50%  

60%  

70%  

80%  

90%  

100%  

2005  

2010  

2015  

2020  

2025  

2030  

2035  

2040  

2045  

2050  

2055  

2060  

2065  

2070  

2075  

2080  

2085  

2090  

2095  

RE  

0%  

10%  

20%  

30%  

40%  

50%  

60%  

70%  

80%  

90%  

100%  

2005  2015  2025  2035  2045  2055  2065  2075  2085  2095  

NucCCS_3.7  

0%  

10%  

20%  

30%  

40%  

50%  

60%  

70%  

80%  

90%  

100%  

2005  2015  2025  2035  2045  2055  2065  2075  2085  2095  

RE_3.7  

Hydro  

Wind  

PV  

CSP  

Geothermal  

Nuclear  

Biomass  CCS  

Biomass  

Oil  CCS  

Oil  

Gas  CCS  

Gas  

Coal  IGCC  CCS  

Coal  IGCC  

Coal  

Water Withdrawals by Scenario

0  

100  

200  

300  

400  

500  

600  

700  

800  

2000   2020   2040   2060   2080   2100  

km3 /yr  

Withdrawals  

0  

5  

10  

15  

20  

25  

30  

35  

2000   2020   2040   2060   2080   2100  m

3 /MWh  

Withdrawal  Intensity    

!   Dramatic decline in withdrawal intensity in all scenarios as older power plants are retired !   This change is consistent with the trends of the last two decades based on

the available evidence !   RE scenarios generally have lower water withdrawal intensity

NucCCS  

NucCCS_4.5  

NucCCS_3.7  

RE  

RE_4.5  

RE_3.7  

Hydro  (all)  

Water Consumption by Scenario

0  

50  

100  

150  

200  

250  

300  

2000   2020   2040   2060   2080   2100  

km3 /yr  

ConsumpKon  

0  

0.2  

0.4  

0.6  

0.8  

1  

1.2  

1.4  

1.6  

1.8  

2000   2020   2040   2060   2080   2100  m

3 /MWh  

ConsumpKon  Intensity    

!   Switch from once-through flow to evaporative cooling amounts to a shift from water withdrawals to water consumption !   The consumption:withdrawal ratio is 0.05 in the base year !   In the NucCCS scenarios, it increases to 0.20 !   In the RE scenario, it increases to ~0.30 !   In the RE_policy scenarios, it increases to ~0.60≈

NucCCS  

NucCCS_4.5  

NucCCS_3.7  

RE  

RE_4.5  

RE_3.7  

Hydro  (all)  

Water Withdrawals by Technology

0

100

200

300

400

500

600

700

800

km^3/yr

NucCCS  

0

100

200

300

400

500

600

700

800NucCCS_3.7  

0

100

200

300

400

500

600

700

800

km^3/yr

RE

0

100

200

300

400

500

600

700

800RE_3.7

Hydro  Wind  PV  CSP  Geothermal  Nuclear  Biomass  CCS  Biomass  Oil  CCS  Oil  Gas  CCS  Gas  Coal  IGCC  CCS  Coal  IGCC  Coal  

Water Consumption by Technology

0

50

100

150

200

250

300

350

km^3/yr

NucCCS

0

50

100

150

200

250

300

350NucCCS_3.7

0

50

100

150

200

250

300

350

km^3/yr

RE

0

50

100

150

200

250

300

350RE_3.7

Hydro  Wind  PV  CSP  Geothermal  Nuclear  Biomass  CCS  Biomass  Oil  CCS  Oil  Gas  CCS  Gas  Coal  IGCC  CCS  Coal  IGCC  Coal  

Sensitivity Analysis - CCS Water Demands

!   The potential range of CCS water demands is large. Switching from a pulverized coal power plant without CCS to… !   PC with post-combustion capture doubles the water demands !   IGCC or oxy-fuel with CCS increases the water demands marginally !   IGCC or oxy-fuel with CCS and using either dry cooling or seawater-based

cooling reduces the water demands by 80% !   Switching from evaporative cooling to dry cooling also increases costs and

decreases thermal efficiency

0  

50  

100  

150  

200  

250  

2000   2020   2040   2060   2080   2100  

EJ/yr  

Electricity  GeneraKon  

0  10  20  30  40  50  60  70  80  90  100  

2000   2020   2040   2060   2080   2100  

km3 /yr  

Water  ConsumpKon  

NucCCS   NucCCS_3.7  

NucCCS_3.7_hi   NucCCS_3.7_lo  

Sensitivity Analysis – CSP Water Demands

0  

50  

100  

150  

200  

250  

2000   2020   2040   2060   2080   2100  

EJ/yr  

CSP  Electricity  

!   CSP with thermal storage is very large in scenarios with limited other options for producing baseload electricity

!   The range in the water demand intensities depends on cooling systems. Compared to the baseline scenarios here… !   Using only evaporative cooling towers doubles the water demands !   Using only dry/hybrid cooling systems reduces electricity generation by

30% (due to higher costs), and water demands by 85%

0  

50  

100  

150  

200  

250  

2000   2050   2100  

km3 /yr  

CSP  Water  ConsumpKon  

RE   RE_3.7   RE_3.7_hi   RE_3.7_lo  

Conclusions

!   Water withdrawals in all scenarios investigated here remain relatively flat for the next few decades !   Retirement of old power plants with once-through flow systems !   New builds use mostly evaporative cooling systems !   By 2050, 85% of the stock did not exist in the model base year, so there is

a high degree of capital turnover !   Water consumption increases in all scenarios

!   Where the present-day electric sector only consumes (evaporates) 5% of its water withdrawal, these scenarios describe systems where this ratio is between 20% (NucCCS technology) and 60% (RE technology with mitigation policy)

!   Water should not be seen as an obstacle to CCS in the long term !   For post-combustion capture (whether retrofits or new builds), the water

demand increases from CCS are substantial !   However, in the long run with known or expected carbon prices, the IGCC

and/or oxy-fuel plants would be the more relevant choices to analyze !   Finally, the additional costs of dry cooling do not increase the costs

prohibitively; this technology set remains valuable in mitigation

Extra Slide: Characteristics of Technology Strategies

Technology  strategy  

Technology  area   NucCCS   RE  

Nuclear  Power   Capital  and  O&M  costs  decline  at  0.1%  per  year  Very  high  capital  costs  

($10,000  /  kW)  

Carbon  Capture  &  Storage  (CCS)   CCS  not  limited  by  availability  of  CO2  storage  reservoirs  Small  storage  capaciIes  for  

geologic  CO2  storage  

Solar   Costs  decline  by  1%-‐2%  per  year,  2005-‐2050  Costs  decline  by  2%-‐3%  per  

year,  2005-‐2050  

Wind   Costs  decline  by  0.25%  per  year,  2005-‐2050  Costs  decline  by  0.5%  per  year,  

2005-‐2050  

Geothermal   EGS  not  available   EGS  available  and  cost-‐effecIve