Water Consumption Impacts of Renewable Technologies: The ... › files › macknick-awra.pdf · CSP technologies have lower water use per land area than many other land-uses 0.0 0.5

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AWRA 2011 Spring Specialty Conference:MANAGING CLIMATE CHANGE IMPACTS ON WATER RESOURCES: ADAPTATION ISSUES, OPTIONS, AND STRATEGIES

Jordan MacknickRobin NewmarkCraig Turchi

[email protected]

National Renewable Energy LaboratoryGolden, Colorado, USA

Water Consumption Impacts of Renewable

Technologies: The Case of CSP

Innovation for Our Energy FutureNational Renewable Energy Laboratory

Concentrating Solar Power (CSP)

Technology types

Parabolic trough

Linear Fresnel

Power tower

Dish/Stirling

Innovation for Our Energy Future

CSP technologies with thermal energy storage are dispatchable

like conventional electricity generating technologies

3

Ph

oto

co

urt

esy S

ola

r M

ille

nn

ium

AG

Thermal energy storage systems

with molten salts allow electricity to be

generated when the sun is not shining

Electricity can be “dispatched” when it

is needed most throughout the day


Wet Cooled (Cooling Towers)

Dry Cooled (Air Cooled Condensers)

Hybrid Cooled (Both cooling towers and air cooled condensers)

4

CSP cooling technology options

Innovation for Our Energy Future5

Water Supply Constraints Coincide with Best

CSP Plant Locations in the US

Water Sustainability Index - EPRIS.B. Roy, K.V. Summers, and R.A. Goldstein, “Water Sustainability in

the United States and Cooling Water Requirements for Power

Generation,” Universities Council on Water Resources Water

Resources Update, Issue 126, Pages 94-99, November 2003.Projected CSP deployment in US(preliminary)


24 Solar Energy Zones developed by the Bureau of Land

Management (BLM) and Department of Energy (DOE)

-~ 21 million acres of BLM land available for CSP

-By 2030, 24 GW on 200,000 acres of BLM land

6

CSP could play a larger role in our electricity

supply

Source: Argonne National Laboratory


Policy Limits Water Availability

Arizona

Senator Kyl report recommends

“eliminating the eligibility of CSP

for the RPS unless the plant will

be dry-cooled or will use an

alternative water source such as

treated effluent.”

Office of Senator Jon Kyl

Deploying Solar Power in the State of Arizona: A

Brief Overview of the Solar-Water Nexus,

Washington, DC, May 2010.

California

“…will approve the use of fresh

water for cooling purposes by

power plants … only where

alternative water supply sources

and alternative cooling

technologies are shown to be

environmentally undesirable or

economically unsound.”

California Energy Commission

Best Management Practices & Guidance

Manual: Desert Renewable Energy Projects,

page 65, December 2009.

7


How CSP Works (parabolic trough)

Solar

Collector

Thermal

Storage

Steam/Electricity

Production

Cooling


How CSP Uses Water (parabolic trough)

Cleaning

~20-40

gallons/

MWh

Cooling: ~750-950 gallons/MWh

Makeup

~30-60

gallons/

MWh


How CSP Uses Water (parabolic trough)

Cleaning

~20-40

gallons/

MWh

Cooling: ~0 gallons/MWh

Makeup

~30-60

gallons/

MWh

Air

Cooled

Condenser


Comparison of Water Consumption Rates

Source: Macknick et al., 2011


Comparison of Water Consumption Rates

Source: Macknick et al., 2011= CSP technologies


Performance tradeoffs

Cost tradeoffs

Dependency on local climatic conditions

Alamosa, CO vs. Las Vegas, NV

13

Wet vs. Dry vs. Hybrid Cooled CSP?


Climatic conditions affect CSP performance

and cooling technology performance

Hotter areas will lead to lower thermal efficiencies

These performance penalties are more pronounced when switching to dry cooling

14

92%

93%

94%

95%

96%

97%

98%

99%

100%

Las Vegas, NV Alamosa, CO

Effect of location on plant output for different cooling technologies

Wet Cooling

Hybrid Cooling

Dry Cooling

Adapted from Turchi et al. (2010)

Implications for reliability of

CSP systems in extreme

weather conditions


Dry and Hybrid Cooling Systems increase

Capital Costs by 2% to 7%

15

0.96

0.98

1.00

1.02

1.04

1.06

1.08

Las Vegas, no storage Las Vegas, 6 hr TES Alamosa, 6 hrs TES

Inst

alle

d C

ost

(r

ela

tive

to

we

t co

ole

d)

Wet Dry Hybrid


Climatic conditions affect CSP costs of

energy generation

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

Alamosa Las Vegas, no TES Las Vegas Daggett

LCO

E in

cre

ase

vs.

wet

-co

ole

d D

esi

gn

Dry

Hybrid

Wet

Compared to wet-cooled System, LCOE increase ranges from 2.5% to 7.5%

Adapted from Turchi et al. (2010) TES: Thermal Energy Storage


Summary Comparison of CSP Cooling Types

Installed Cost

Operational Costs

ParasiticLoads

Effective Cooling in

Arid Climates

Water Consumption

Cooling Tower Blowdown

Pond

Best Wet cooling Dry Cooling Wet CoolingWet Cooling

Hybrid CoolingDry Cooling Dry Cooling

WorstHybrid Cooling

Wet Cooling

Hybrid CoolingDry Cooling Dry Cooling Wet Cooling

Wet Cooling

Hybrid Cooling

Wet and Hybrid Cooling

Dry Cooling

Hybrid Cooling

Wet Cooling


CSP 2050: deployed primarily in the SW: water impacts

18

CSP Percent of Total Generation

<0%

>25%

Wet-cooled

Gallons

<0

>50 Billion

Dry-cooled

Gallons

<0

>50 Billion

Gallons

<0

>50 Billion

Hybrid-cooled


CSP 2050: Cooling technology can affect water needs

19

CSP Percent of Total Generation

CSP using dry cooling can result in a relatively minor proportion of power sector water consumption overall

<0%

>25%

<0

>50

Wet-cooled

% Consumption

<0

>50

Dry-cooled

% Consumption


Total Freshwater Withdrawals by Sector

0

5

10

15

20

25

30

35

40

Arizona California Colorado Nevada New Mexico Texas Utah

Mill

ion

Acr

e-F

ee

t p

er

year

Freshwater Withdrawals in 2005 (USGS)

Thermoelectric

Mining

Industry

Aquaculture

Livestock

Irrigation

Domestic

Public Supply

National Average : Thermoelectric = 41% of total freshwater withdrawalSouthwest Average: Thermoelectric = 12% of total freshwater withdrawalSouthwest sans Texas: Thermoelectric = <1% of total freshwater withdrawal


CSP technologies have lower water use per

land area than many other land-uses

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

CSP (wet_cooled)

CSP (dry_cooled)

PV Alfalfa Cotton Fruit Trees Golf Courses

Acr

e-f

t /

acre

pe

r ye

ar

Sources:CSP: Reducing Water Consumption of CSP Electricity Generation, Report to Congress 2009.Crops: Blaney, Monthly Consumptive use of Water by Irrigated Crops & Natural Vegetation, 1957.Golf : Watson et al., The Economic Contributions of Colorado’s Golf Industry: Environmental Aspects.

Courtesy: Craig Turchi, NREL


Summary of CSP water issues

CSP technologies have the potential to play a large role in a clean energy economy

Wet cooled CSP systems have higher water consumption rates than many non-renewable technologies.

Dry cooled CSP systems have lower water consumption rates than many non-renewable technologies

CSP technologies (wet and dry cooled) can reduce overall water consumption on former agricultural lands

Careful consideration regarding technology choices is required on a site-by-site basis

Dry cooling decreases output in hot areas by ~5%, and less in cooler areas, if an appropriate air-cooled condenser size is chosen

Dry cooling decreases water consumption by ~92%

Shift to dry cooling raises LCOE by 2.5% to 7.5% depending on climate


Investigate alternative hybrid cooling options

• Cooling system switching (not parallel)

• Spray cooling air to ACC

• ACC deluge

Wash water capture and reuse

Utilizing alternative sources of water for cooling

23

Other research and opportunities to minimize

water impacts of CSP


Thank you

Contributors: Robin Newmark, Craig Turchi, Michael Wagner, and Chuck Kutscher

We would like to acknowledge the support of Craig Zamuda from the Department of Energy’s Office of Policy and International Affairs.

Jordan Macknick

(303) 275-3828

[email protected]

Useful websites:

NREL CSP homepage: http://www.nrel.gov/csp/

Solar Power and the Electric Grid Factsheet: http://www.nrel.gov/csp/pdfs/45653.pdf

Solar Power Prospector: http://maps.nrel.gov/

Solar PEIS homepage: http://solareis.anl.gov/

SolarPaces homepage: http://www.solarpaces.org/

mailto:[email protected]

http://www.nrel.gov/csp/

http://www.nrel.gov/csp/pdfs/45653.pdf

http://maps.nrel.gov/

http://solareis.anl.gov/

http://www.solarpaces.org/

Water Consumption Impacts of Renewable Technologies: The ... › files › macknick-awra.pdf · CSP technologies have lower water use per land area than many other land-uses 0.0 0.5

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