Water/Energy Relationship at
SDG&E
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San Diego Gas & Electric Presentation
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SDG&E Water Connection
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San Diego Gas & Electric Presentation
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One Year’s Difference in Snowpack
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San Diego Gas & Electric Presentation
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Nexus
 The water-energy relationship is typically quantified via the
energy intensity of water measured in kilowatt-hours or
therms per acre-foot (kWh or Therms/AF).
 Energy intensity is calculated as the total amount of energy
required to move a unit of water.
 𝐸𝑛𝑒𝑟𝑔𝑦 𝐼𝑛𝑡𝑒𝑛𝑠𝑖𝑡𝑦 =
𝑇𝑜𝑡𝑎𝑙 𝐸𝑛𝑒𝑟𝑔𝑦 𝐶𝑜𝑛𝑠𝑢𝑚𝑒𝑑 (𝑇ℎ𝑒𝑟𝑚𝑠)
𝑇𝑜𝑡𝑎𝑙 𝑊𝑎𝑡𝑒𝑟 𝐷𝑒𝑙𝑖𝑣𝑒𝑟𝑒𝑑 (𝐴𝐹)
 Different water supplies have different energy intensities;
imported water is among the most energy intensive
(especially in Southern California).
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San Diego Gas & Electric Presentation
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San Diego “Au Natural”
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History of the Water/Energy in
California
Water – Energy Relationship in CA
• Water-related energy use is about 20% of total electric consumption
and 30% of total therm consumption in California
• Water-related energy use
• End uses: heating, cooling, on-site pumping
• Upstream uses: surface conveyance, groundwater pumping,
treatment, distribution
• Downstream uses: waste water pumping and treatment
• Upstream and downstream water-related energy use in
California
• About 12.5 Billion kWh/yr embedded upstream and
downstream of the water customer
• In Southern California, majority is due to conveyance
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Current Energy Division Policy
• Current Policy does not allow IOUs to claim embedded
savings
• Methodology of calculating the embedded savings needs
to be agreed upon and unified
• Right now only “DIRECT” energy savings can be claimed
• Currently there is no agreement on how much
embedded energy usage is in transfer/conveyance/
heating of water or where the savings can be claimed
• After a CPUC workshop held in May 2013 it was
determined energy intensity varies widely by region
• Navigant has been hired by the CPUC to determine
energy intensity by region w/in the State
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Water/Energy Uses

Water infrastructure requires energy use in almost every segment and
facility.

The typical energy consuming segments of the water infrastructure:
Supply and Conveyance - Reservoirs, canals, pump stations and
groundwater pumps that produce and transport raw, untreated water.
Examples include many of the facilities that the State Water Project and
Colorado River Aqueduct operate.

Water Treatment

Water Distribution

Wastewater Collection

Wastewater Treatment

Recycled Water Treatment

Recycled Water Distribution
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Water Conservation and Energy
Savings
Direct vs. Indirect Energy Savings
•
Direct energy savings are those that appear on the customer’s energy
meter
•
Indirect energy savings do not appear on the customer’s energy meter
•
•
Occur upstream and downstream of the customer
Are due to the customer’s reduction in use of some other resource
•
Energy embedded in water upstream and downstream of a water
customer can be saved if that customer reduces their water use
•
Direct water savings = Indirect energy savings
•
Estimated embedded energy intensity for urban water throughout
California
•
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Southern California: 13,000 kWh/MG
San Diego Gas & Electric Presentation
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Three Levels of Water/Energy Efficiency
Type of measure
1. Energy savings associated with water
Example opportunities
Efficient water heater
2. Combined water and energy savings for end user
Low flow showerhead
3. Water conservation only (upstream/ embedded energy) High efficiency toilet
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San Diego Gas & Electric Presentation
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SDG&E’s History w/San Diego
County Water Authority
• SDG&E has a twenty plus year relationship with SDCWA
• Through our decades-long Partnership some of our achievements
include:
– Giving out half a million low-flow showerheads
– Helping small businesses w/water equip installations, at low or
no-cost
– Making high-efficiency washers affordable for customers through
our joint rebate program
• Established a formal Institutional Partnership with SDCWA in 2008
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SDG&E Efforts for
2013-2014 Program Cycle
•
What’s New in 2013-2014?
– Institutional Partnership with San Diego County Water Authority
• Per the Decision the CPUC mandated efforts for Water/Energy
Nexus include:
– Leak Loss Detection
– Pressure Management
– This effort will be rolled out to SDCWA and member agencies
– Two of the more successful SDG&E Water Pilot programs have been
incorporated as part of this effort:
• A landscape efficiency component will be made available to
commercial properties with an excess of 4 irrigated acres using
monitored weather technology sensors
• A North County detention center will be retrofit with flush valve
controllers, low flow shower heads and toilets
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Leak Loss Detection
• High value targets will be those w/high energy intensity and/or
embedded energy coupled with high levels of leakage
• Acoustic leak detection equipment will be utilized to “listen” for leaks
and make corrections
• Water loss through leakage is directly related to system pressure.
Reducing pressure, where possible, will reduce leakage
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Pressure Management
• Basic tenets of program will remain the same as in the original SCE
pilot held in 2008-2009.
• Water loss through leakage is directly related to system pressure
and , where possible, will reduce pressure
• Pressure Zones or entire systems may have gradually been
increased due to low pressure complaints and/or poor design
• Zones can be adjusted either with current equipment in place or with
installation of flow-modulated pressure reducing valves
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San Diego Gas & Electric Presentation
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WaterSmart Landscape
Efficiency Project
• The program targets commercial properties with at least four acres
of irrigated landscaping. An audit is performed and landscape
equipment will be repaired/replaced/added to and monitored for up
to a year.
• CA Landscape Contractors Assn (CLCA) will be administering the
program.
• SDCWA will provide monies for materials for the program as part of
their participation in the Partnership. SDG&E will cover admin and
labor costs.
• There is no cost to the end user.
• A minimum of 20% savings is the goal for this program.
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San Diego Gas & Electric Presentation
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North County Detention Center
Water Retrofit
• Flush valve controllers, low flow showerheads, low flow toilets will
be installed at facility
• Material funding will be provided by SDCWA
• Parlaying existing Partnership relationship between the County of
SD and SDCWA
• 400 acre feet of water savings achieved at Bailey prison during
2008-2009 water pilot
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UC Davis Study
• UC Davis was hired by PG&E to do an energy intensity study within
their region in partnership with EBMUD
• SDG&E has hired UC Davis to do a similar study with an
appropriate water district in our territory
• This effort is being co-funded by the SDCWA Partnership, Emerging
Technology, and the EM&V group
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What We Prefer San Diego to Look Like
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What We Prefer San Diego to Look Like
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The End!
Questions?
http://www.sdge.com/rebatesfinder/business
http://www.sdge.com/buyers-guide/399
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