The Water Energy Nexus
Donald Bren School of Environmental Science and Management
University of California Santa Barbara
May 8-9, 2008
Michael Murray
Director of Corporate Environmental Policy
mmurray@sempra
California Utilities
San Diego
Gas & Electric
Southern
California Gas
Natural Gas Infrastructure
Global Commodities
Sempra LNG
Sempra Pipelines
& Storage
RBS Sempra
Commodities
Sempra Generation
Page 1
Energy and Water Relationship
Energy production
requires water
• Thermoelectric
cooling
• Hydropower
Water
production
and
distribution
requires
energy
• Extraction and
mining
• Pumping
• Fuel Production
(H2, ethanol)
• Transport
• Emission controls
• Treatment
• Wastewater
treatment
Page 2
Diagram of Energy and Water Distribution Systems
Page 3
Water, Energy and Climate Change Policy Intersection
l
Policy
“Sweet
Spot”
Water Policy
Energy Policy
Carbon
Change Policy
Maximize Policy
synergies by focusing
on areas of overlap.
Page 4
How Energy Impacts Water Quantity and Quality
Energy Element
Connection to Water
Quantity
Connection to Water Quality
Energy Extraction and Production
Oil and Gas
Exploration
Water for drilling, completion,
and fracturing
Impact on shallow groundwater
quality
Oil and Gas
Production
Large volume of produced,
impaired water
Produced water can impact
surface and groundwater
Coal and Uranium
Mining
Mining operations can generate
large quantities of water
Tailings and drainage can impact
surface water and ground-water
Electric Power Generation
Thermoelectric (fossil,
biomass, nuclear,
solar thermal)
Surface water and groundwater
for cooling** and scrubbing
Thermal and air emissions from
impact surface waters and
ecology
Hydroelectric
Reservoirs lose large quantities
to evaporation
Can impact water temperatures,
quality, ecology
Solar PV and Wind
None during operation; minimal water use for panel and blade
washing
Page 5
How Energy Impacts Water Quantity and Quality
Energy
Element
Connection to Water
Quantity
Connection to Water
Quality
Refining and Processing
Traditional Oil and
Gas Refining
Water needed to refine oil
and gas
End use can impact water
quality
Biofuels and
Ethanol
Water for growing and
refining
Refinery wastewater
treatment
Synfuels and
Hydrogen
Water for synthesis or
steam reforming
Wastewater treatment
Energy Transportation
Energy Pipelines
Water for hydrostatic
testing
Wastewater requires
treatment
Coal Slurry
Pipelines
Water for slurry transport;
water not returned
Final water is poor quality;
requires treatment
Barge Transport
of Energy
River flows and stages
impact fuel delivery
Spills or accidents can
impact water quality
Page 6
Water Intensity for Various Power Generation Technologies
From a water use
perspective
natural gas
combined cycle
plants use less
water than any
other generation
technology that
uses cooling.
Dry cooling (air)
reduces water
use, but increases
carbon emissions
and increases cost
due to lost
efficiency (up to
25% on hot dry
days.)
Source: Energy Demands of
Water Resources; Report to
Congress on the interdependency
of Energy and Water, U.S.
Department of Energy, December
2006; page 38.
Page 7
Providing Water is an Energy Intensive Enterprise
kWh/Million
gallons
Low
High
0
16,000
100
1,500
700
1,200
Water Cycle Segments
Supply and Conveyance
Treatment
Distribution
Wastewater Collection
and Treatment
1,100
Wastewater Discharge
0
TOTAL
1,900
4,600
400
23,700
Recycled Water
Treatment and
Distribution for Nonpotable Uses
1,200
Source: CEC 2005
400
• Significant
Energy required to
transport, treat, and
distribute water (about
19% of state electricity
use)
• Costs varies significantly by
local.
–Generally, the greater
the level of imported
water, the greater the
embedded energy in
water.
• Most water is in Northern
California and must be
moved south, often over
mountains in a very energy
intensive process.
• >3500kwh per acre foot to
deliver water to So Cal.
Page 8
Examples : Sempra’s Efforts to Address Water Energy Nexus
• Use of Recycled Water at Generation Stations
• Integrating Water and Energy Conservation Programs
Page 9
Recycled Water USE -- SDG&E’s Palomar Energy Center
100 % of its non-potable water
needs met with recycled water.
–Cooling
–Landscaping
–Firefighting
Uses 3.6 Million Gallons/Day
Source of Recycled water is the
from the City of Escondido's Hale
Avenue Resource Recovery Facility
Delivered via 1.1 mile pipeline.
Page 10
SDG&E Energy and Water Conservation Program
Managed Landscape Pilot Project
• SDG&E contracts with water management service company for a
Managed Landscape Pilot Project, conducted in the San Diego region at
property sites owned by third party participants.
• Ideal location would be a property site with a minimum of four irrigated
acres. The pilot would involve up to approximately 20 sites of four
acres each.
• The objective would be to document and verify achieved water savings
and related energy savings obtained through a guaranteed
performance contract with the participants, based on a preimplementation audit and work plan.
Recycled Water Retrofit
• The County Water Authority and its member agencies would identify
sites with completed retrofit plans that would allow the customer
immediately to switch from potable water usage to recycled water.
SDG&E and the County Water Authority would both provide funding for
eligible projects.
Page 11
SDG&E Energy and Water Conservation Program (cont.)
Large Customer Audits
• The San Diego County Water Authority and SDG&E each audit the
facilities of large customers, but normally focus only on water or
energy, respectively. For the pilot program, the County Water
Authority and SDG&E will integrate these audits in a two-part program
strategy.
• First, pursue improvements already recommended by the County
Water Authority as a result of prior audits.
–SDG&E provides funding to encourage high-priority improvements, i.e., cost
effective energy efficient and water efficient measures, which cannot be
funded through other water agency incentive programs.
–The County Water Authority would also contribute funds
• Second, The County Water Authority and SDG&E would collaborate in
the development of a comprehensive water/energy audit
tool/instrument to incorporate the lessons learned from the first part of
the audit strategy discussed above.
Page 12
Southern California Gas -- Energy and Water Conservations
• Lake Arrowhead/SCE/SoCalGas Water Conservation Partnership
• SoCalGas would collaborate with Lake Arrowhead and SCE on an
Indoor/Outdoor Retrofit Program for residential customers. Project has
both indoor and an outdoor components.
• The indoor portion of the program would apply to homes built prior to
1992, that are year round residences.
– These homes are most likely to have older fixtures that are predominantly
inefficient in both water use and energy use.
• The outdoor portion of the program would apply to approximately
1,000 homes which use approximately 1/3 of Lake Arrowhead’s annual
water supply. The following retrofits would be included in the program:
– Replace 5 gallons per flush toilets with efficient 1.3 gallons per flush toilets.
– Replace older shower heads with more efficient fixtures, reducing flow from
4.5 gallons per minute to 2.0 gallons per minute
– Replace older clothes washers with higher efficiency machines, resulting in a
lifetime savings of 0.314 acre feet per machine (14-year lifetime).
– Install new water saving aerators.
– Install ET/Smart Controllers and more efficient sprinkler hardware.
Page 13
Southern California Gas -- Energy and Water Conservations (cont.)
Pump/Engine Testing/Evaluation Program for Crestline-Lake
Arrowhead Water Agency and Eastern Municipal Water District
• First phase: natural gas pump/engine testing/evaluation program.
–Results used to develop natural gas pump/engine efficiency
improvement program.
• Water utilities in the state operate approximately 600 natural gas
pump/engines. Pilot program would cover approximately 150 gas
engines in the SoCalGas service territory.
• The pilot testing/evaluation phase would lead to an evaluation of each
water utility natural gas engine/pump, with efficiency rankings and
recommendations for improving the efficiency of both the pump and
engine.
Page 14
Utility Technology – Smart Meters
SDG&E will install two-way communicating Smart Meters throughout
its service territory to provide: greater customer awareness and
control of energy use, enhanced customer service and faster outage
detection and response.
–Replace 1.4 million electric meters, upgrade 900,000 gas meters
–Part of statewide effort
–First 5,000 meters installation – April 2008 in Tierrasanta
–Broad rollout beginning in 4Q 2008
–Usage data will be available via Internet, phone
–Cost: $500 million
–In the future: Home Area Network functionality allows for
customer choice with enabling technology – automated control of
appliances, electronics.
Page 15
Energy Efficiency
Benefits of Sempra Energy Utilities’ energy
efficiency and demand response programs:
•Savings of millions of MW hours and millions
of therms of natural gas
•Deferral of new generation
•Cumulative savings in the hundreds of
millions of dollars
•Millions of tons avoided CO2 emissions
Page 16
Summary
Water and Energy Use Inextricably linked
•Conservation and Efficient use most effective approach at managing
resource
•Conventional supplies limited: Need for more renewables for
electricity and recycling for water
•Limited options for transmission of resource
•Need for cross fertilization of innovative technologies e.g. smart
time of use meters
Page 17