1

Larry DaleEnergy Analysis

Modeling Energy Water Use in California: Overview

Ernest Orlando Lawrence Berkeley National Laboratory

November 24, 2011

2

Modeling Energy Water Use in California

• Larry L. Dale, Michael Hanemann,

– LBNL, UC Berkeley

• Charles F. Brush, Tariq N. Kadir, Emin C. Dogrul

– California Department of Water Resources

3

Summary

• Introduction to California water and energy

• Energy-water linkages

• Climate change and management

• Modeling energy water

• Groundwater case study

• Conclusion

4

Water Storage and Delivery System

Supply in North and East

Demand in South and West

Moderately-sized reservoirs

Store winter precipitation as Sierra

snowpack

State

Local

San Diego

Los Angeles

San Francisco

Federal

Complex east-west and north-south distribution system combining rivers, canals and storage reservoirs

5

6

Energy-Water LinkagesSector Activities

Power Generation

• Thermal Cooling

• Hydropower

Water Utilities

• Pumping

• Transfers long distance

• Treatment

• Wastewater Treatment

Residential

• Cooling (AC)

• Water Heating

Commercial & Government

• Water Cooling Towers

• Heating

Agriculture

• Irrigation

• Drip and flood

• Pumping groundwater

Industrial

• Cooling

• Heating

Overview of Water-Energy Interactions

7

Q. I Q. II

Q. III Q. IV

GroundwaterPumping

Energy-Water LinkagesMethods for Managing Energy-Water

Consume

Energy &Water

Produce Water Consume Water

Co

nsu

me E

ne

rgy

Pro

du

ce

En

erg

y

Consume Energy

to Produce Water

Produce

Energy & Water

WaterConveyance

Residential End-Use

Agriculture

Reservoir

Bio-Fuel Crops

Consume Water

to Produce Energy

Thermoelectric Cooling

Conservation

MeasuresResidential

Conservation

Pressurized

Irrigation

Overview of Water-Energy Interactions

8

I. Historical Energy Water Management in CACheap Energy to Supply Water

Energy Input

kWh

Water Output

Acre-Foot

2.7kWh/m3

Reservoirs - 500 kWh per AF

Groundwater (Central California)365 kWh per AF

Drip Irrigation586 kWh per AF

Conveyance (Los Angeles)3,323 kWh per AF

Residential End-Use(Los Angeles)4,128 kWh per AF

Source: Bulletin 160-2000, CA Department of Water Resources

Navigant Consulting. "Refining Estimates of Water Related Energy Use in California." California Energy Commission.

CEC 500-2006-116. 2006.

0

0

Overview of Water-Energy Interactions - California

.29 kWh/m3

3.35kWh/m3

9

II. Climate Change & Adaptive

Management

• Climate change

– Impacts water scarcity value

– Impacts electricity scarcity value

• Direction of adaptive water energy

management

Climate Change Impacts

Many Temperature and Precipitation ForecastsFor water supply, the key variable is likely to be temperature rather than precipitation

Clearly warmer

Not certain about

precipitation

Increasing Temperatures

11

Electricity Impacts• Need for generation

• Peak Period Demand Rise

•10 % - 21%

•Peak Period Supply Loss (Natural gas plant)

• 1% - 3.6%

• 4% - 6.2% max

•Transmission and Distribution Loss

• up to 1% - 2%

• Need perhaps 25% additional generation

capacity

•Need for transmission capacity

• Sub-stations

• 2% to 3% loss in capacity

• Transmission lines

•7% - 8% loss of capacity

•Limited data on sizes, locations, and

usage capacity

• Need perhaps 25 % additional transmission

capacity

12

Projected fire risk to transmission lines for the A2 scenario

13

14

Adaptive Management

• Uncertainty about increase in temperature and changes in water demand

• Most scenarios hotter and dryer– increased value for water and energy

• Some hot wet scenarios-- increase energy elative to water value

• Few “cool” dry scenarios--increase water relative to energy value

Climate Change Impacts

15

Q. I Q. II

Q. III Q. IV

GroundwaterPumping

Adaptive Management

Consume

Energy &Water

Produce Water Consume Water

Co

nsu

me E

ne

rgy

Pro

du

ce

En

erg

y

Consume Energy

to Produce Water

Produce

Energy & Water

WaterConveyance

Residential End-Use

Agriculture

Reservoir

Bio-Fuel Crops

Consume Water

to Produce Energy

Thermoelectric Cooling

Conservation

MeasuresResidential

Conservation

Pressurized

Irrigation

Overview of Water-Energy Interactions

Energy and Water Complements

Energy and Water Substitutes

Research Applications

16

1. Energy Water Modeling

2. Groundwater

17

Water-Energy Model of the American

River SystemWEAP-LEAP Model

• Determine the water-energy nexus in an “almost” closed system – the American River basin

• Determine how the linkages between water and energy are sensitive to changes in climate

• Determine different water and energy management strategies and their trade-offs

WEAP-LEAP Model

18

Area of StudyWater Purveyors of Sacramento Area

Sacramento

River

American River

Sacramento

and American

River Junction

18

Folsom

Reservoir

WEAP-LEAP Model

19

Sacramento Area Land-UseArea of Study

WEAP-LEAP Model

SMUD Service Area

21

WEAP-LEAP

Model Development Plan

•Phase 1. Develop hydrology model for the American basin

•Phase 2. Develop electricity model for SMUD service area

•Phase 3. Develop a Linkage between the two models

21

WEAP-LEAP Model

WATER DATA

Demand

• Water Customer Profile (RWA utility

billing data)

– Aggregate Monthly Water Use by

Customer Class (RWA utilities, for

residential, commercial, industrial, Power sector)

Supply

• Water Use & Electricity Load Profile (SMUD billing data combined with water

utility water use, kWh per mil gal)

– Pumping Loads

• Amt of Water Processed

• Amt of Electricity Consumed

– Treatment water and electricity

use (estimate?)

ENERGY DATA

Demand

• Energy Customer Load Profile

– Electricity Use by Customer

Class (SMUD users, for residential,

commercial, industrial, water utility)

Supply

• Electricity Supply Load Profile

– Hydropower Generation and

Release Schedule (million gal/kWh)

– Thermal generation

– Purchased power

22WEAP-LEAP Model Data

WEAP-LEAP Data RequirementsClimate-Driven Changes to Water-Energy

Data RequirementsClimate-Driven Changes to Water-Energy

City of Sacramento Water Demand (Million Gallons per Day)

SMUD Total Hourly Electrical Load (10’s of Megawatts)

Temperature at the Sacramento Airport (Degrees Farenheit) 23

24

SCENARIOHIGHER TEMPERATURES

& LOWER SUMMER WATER FLOWS

1. Constrained Hydropower2. Higher Cooling Demand (AC)3. More Groundwater Pumping4. Higher Prices

1. Higher Summer Demand2. Lower Groundwater Levels3. Higher Prices

WEAP-LEAP Scenario AnalysisClimate Scenario, System Impacts and Management Responses

WEAP-LEAP Model: Climate Scenarios and Management Responses

IMPACT ON WATER IMPACT ON ENERGY

25

Climate impacts on groundwater, cropping and energy demand

– Impacts on water supply

– Impacts on cropping

– Impacts on groundwater

26

California’s Central Valley

� 55,000 sq. km. (20,000 sq. mi.)

� 25 MAF/yr surface water discharge

� Agricultural Production� 6.8 million acres (27,500 sq. km)

� 10% of US crops value in 2002

� Population growth� 1970: 2.9 million

� 2005: 6.4 million

� Pumping� ~9 MAF in 2002, or 13% if US pumping

� Not measured or regulated

27

Water Storage and Delivery System

Supply in North and East

Demand in South and West

Moderately-sized reservoirs

Store winter precipitation as Sierra

snowpack

State

Local

San Diego

Los Angeles

San Francisco

Federal

Complex east-west and north-south distribution system combining rivers, canals and storage reservoirs

28

C2VSIM Model Grid

IWFM Application

Groundwater System– Finite Element grid– 3 layers

– 1393 nodes

– 1392 elements

Surface Water System– 72 stream reaches

– 97 surface water diversion points

– 2 lakes

– 8 bypass canals

Land Use Process– 5 Regions

– 21 Subregions

– 4 Land Use TypesAgriculture Urban

Native Riparian

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Water Budget

30

Pumping and Surface Water

31

Research Issues

• The ‘stationarity’ assumption– Changes to surface water availability and variability

– Physical infrastructure, population, economics

• Climate change impacts– Changes to water supply1

– Impacts on hydropower2

– Impacts on agriculture3

– Strategies for adapting to these changes4

– Impacts on groundwater

• 1. Emissions Pathways, Climate Change, and Impacts on California. K. Hayhoe, D. Cayan, C. Field, P. Frumhoff, E. Maurer, N.

Miller, S. Moser, S. Schneider, K. Cahill, E. Cleland, L. Dale, F. Davis, R. Drapek, M. Hanemann, L. Kalkstein, J. Lenihan, C.

Lunch, R. Neilson, S. Sheridan, J. Verville. Proceedings of the National Academy of Sciences. 2004.

• 2. Climate Change Impacts on High Elevation Hydropower Generation in California’s Sierra Nevada: A Case Study in the Upper

American River. S. Vicuna, R. Leonardson, W. M. Hanemann, L.L. Dale, and J.A. Dracup. Climatic Change (2008)

• 3. Climate Change Impacts on Water for Agriculture in California: A case study in the Sacramento Valley. B. Joyce, S. Vicuna, L.

Dale, D. Purkey, M. Hanemann, J. Dracup, D. Yates, Climatic Change. In press. June 2007.

• 4. Basin Scale Water Systems Operations under Climate Change Hydrologic Conditions: Methodology and Case Studies

Sebastian Vicuna, John Dracup, Jay Lund, Larry Dale, Ed Mauer. Water Resources Research. February, 2009

32

Research Questions

� How sensitive are groundwater levels to climate-dependent inputs and groundwater pumping?

� Will the surface water-groundwater system reach a new equilibrium after extended surface water reductions?

� To what extent will changes in cropping patterns reduce impacts on groundwater levels?

� How will changes in energy prices and bio-fuel crop acreage impact groundwater levels?

33

Methodology

� Construct valley-rim inflows for drought scenarios

• 30%, 50% and 70% less precipitation

• Develop diversion scenarios using CALSIM-II

� Groundwater model (C2VSIM) simulations

• 10-year spin-up at ‘average’ conditions

• 20-, 30- or 60-year drought; 30-year recovery period

• Calculate groundwater pumping and groundwater depths

� Crop production model (CVPM simulations

� Simulate average and drought period crop acres

� Estimate crop response equation and link to C2VSIM

� Groundwater model (C2VSIM-CVPM) simulations

� Fixed agricultural water demand5

1) Variable agricultural water demand

� 5. Drought Analysis of the California Central Valley Surface Groundwater Conveyance System

� N. Miller, L. Dale, S.Vicuna, T. Kadir, E. Dogrul and C. Bush. JAWRA. August, 2009.

34

Water Sources

70% reduction for 60 years

35

Relative Water Level Change

30% for 10 years 70% for 60 years

Relative WT Change (Feet)

36

Incorporating Variable Demand

� Model crop production

� Central Valley Production Model

� Crop Acres = f (crop costs and prices, surface water availability, groundwater depth)

� Estimate crop response function (logit equation) parameters from simulation analysis usingCentral Valley Production Model

� Check accuracy of crop response function

� Incorporate response function into groundwater model (IWFM application)

37

Variable Crop DemandNet Crop Value, Tulare Basin

Tree crops

Field crops (tomato, cotton)

Pasture

Source: , CVPM crop budgets

38

Central Valley Production ModelEconomic Model

o Positive mathematical Programming Model

o Crop production costs, yields and prices

o Crop distribution in Central Valley

Emulate CVPM in IWFM

• Use crop response function to determine crop mix

• Determine parameters with multiple CVPM runs

C2VSIM and CVPM

• 21 Subregions

• Crops

• Time Step

39

Multinomial logit

40

Logit equation accuracyEstimated crop shares within 1-3% of CVPM crop shares

-6%

-5%

-4%

-3%

-2%

-1%

0%

1%

2%

3%

4%

0 % 10 % 2 0 % 3 0 % 4 0 % 5 0 %

Actual Crop Share

Cereal

Orchard

Pasture

Rice

Row

Fallow

Water UseFixed and Adjustible-Crop Simulations

0

5,000

10,000

15,000

20,000

25,000

2004 2014 2024 2034 2044 2054 2064 2074 2084 2094 2104

Water Year

Wa

ter

Use

(T

AF

/Yr)

Diversions

Pumping - Adjusted Crops

Pumping - Fixed Crops

70% reduction for 60 years

Difference in Pumping HeadFixed-Crop and Adjustable-Crop Simulations

-160

-140

-120

-100

-80

-60

-40

-20

0

20

2004 2014 2024 2034 2044 2054 2064 2074 2084 2094 2104

Water Year

Pu

mp

ing

he

ad

(ft

)

Sacramento Valley

San Joaquin River Basin

Tulare Basin

43

Drought Impact on Electricity UseRise in groundwater electricity cost (kWh/ac ft)

0

50

100

150

200

250

300

350

2014 2034 2054 2074

Year

Incre

ase in e

lectr

icit

y u

se (

kW

h/a

c f

t)

Tulare basin

San Joaquin Basin

Sacramento

44

Conclusion

• Water Energy interactions– Pervasive energy to supply water link

– More region specific water to supply energy link

• Climate change impact on energy and water prices– Helps determine direction of adaptive response

• Modeling efforts to explore– Size of energy and water linkages

– Impact of climate change on linkages

– Management options