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WATER ENERGY

Measures

There are many high potential opportunities to save both water and energy – both by the states’ water infrastructure and by consumers of water. 

During the conduct of its 2005 report on California’s Water–Energy Relationship, the CEC sought input from water and energy stakeholders on the greatest potential for positively affecting the state’s water-energy relationship.   Stakeholder recommendations that appear in Appendix E of the report are summarized here.  Some of these measures can be achieved within existing policies, rules, regulations and infrastructure.  Others will require changes to infrastructure, polices, practices and technologies.

Water Use Cycle

Water-Energy Measures

Supply and Conveyance
  • Install high efficiency pumps
  • Increase the use of recycled water
  • Optimize integration of renewable energy sources and the use of water storage for energy storage
  • Optimize hydropower generation
  • Shift water pumping from the summer months to other months
Water Treatment
  • Install high efficiency pumps
  • Develop lower energy intensity water treatment methods
  • Shift water treatment to off-peak and partial peak times
Distribution
  • Install high efficiency pumps
  • Shift water pumping to off-peak and partial peak times
End-Use
  • Increase energy efficiency of water heating and pumping devices
  • Reduce the use of once-through cooling, thereby slowing reliance on treated water supplies
  • Save energy by conserving water
  • Optimize of the time of use of water by large customers to decrease energy needs during peak times
Wastewater Treatment
  • Increase self-generation of energy by biogas
  • Install high efficiency pumps
  • Advance water treatment processes to decrease energy use
  • Optimize flow and storage to reduce energy use during peak times

The Alliance’s Water‐Energy Advisory Committee came to the consensus that like energy efficiency, water conservation is the most cost‐effective and environmentally preferred action to save energy and water. Conserving a unit of water avoids using the energy that would have been needed to supply, treat, deliver, consume, collect, treat, and dispose of it as wastewater.  The second major opportunity is expansion of the use of recycled water.  The actual amount of energy saved depends upon the energy intensity of the displaced water supply, the nature and extent of its treatment, and the type of end use.

Some of these measures have already been implemented.  Most energy utilities offer programs to help their water agency customers increase the efficiency of their pumps and treatment facilities.  Both water and energy utilities offer programs to reduce hot water usage through more efficient household appliances such as dishwashers and clothes washers to save both water and energy.  Water conservation has even become a priority action for the state. In the 2009 Comprehensive Water Package, California passed into law a requirement to reduce per capita urban water use 20% by 2020 statewide. 

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Water Treatment Plant Operator holding a sample of recycled water
Water Treatment Plant Operator holding a sample of recycled water
Recycled Water Study

In the U.S., many non-potable uses are served by potable water that has been treated to safe drinking water standards established by the federal Environmental Protection Agency and state and local agencies charged with protecting public health and safety.  Recycled water can be used to safely displace use of potable water for these types of non-potable uses such as toilet flushing, landscape irrigation, commercial car washing, and fire protection. 

Recycled water is produced by treating municipal wastewater.  California treated about 5 million acre-feet of municipal wastewater in 2002.  About half of that amount was recoverable as recycled water.  However, as much as 70% is discharged without beneficial use to natural waterways and to the ocean every year, representing a viable, untapped resource – a lost opportunity.

Recycled water could be used to enhance potable supplies after undergoing highly advanced treatment. Several water agencies in Southern California are taking advantage of advanced technologies to produce recycled water that exceeds California drinking water standards.  These agencies are using this recycled water to protect and replenish groundwater aquifers that serve as a major potable supply to the region. 

In May 2008, the Alliance released a study titled The Role of Recycled Water in Energy Efficiency and Greenhouse Gas Reduction that estimated the potential energy and carbon benefits of accelerating and increasing the development and use of recycled water in Southern California.

Results of the study show up to 580,000 acre-feet of existing recycled water supply in Southern California is currently being released to streams and the ocean without benefit.  This supply could meet all of Southern California’s projected increase in water use through 20301 . According to the study, every gallon of recycled water that is not used to offset potable water use is a missed opportunity for California to increase water and energy supplies and to reduce carbon emissions.

Download the full report for more information.  See the appendices for profiles of each of the participating water agencies.

1As projected by the Department of Water Resources under a Business As Usual scenario

Agencies include:

Appendices include:

Water Energy Video

Water-Energy Nexus

Water related energy use accounts for nearly 20% of all electricity consumed in California. Below, Cynthia Truelove, Senior Water Policy Analyst, California Public Utilities Commission, discusses the water-energy nexus and how water can be conserved and used more efficiently to decrease energy usage. As part of California's Climate Action Team focused on water and energy, Cynthia discusses six measures identified as principle targets to reduce GHGs in addition to those required under AB32.

Showcase Water Agencies

In the last two years, the Alliance recognized two water agencies as leaders in sustainability: Inland Empire Utilities Agency and Sonoma County Water Authority. The Alliance celebrates their success and the excellent work they are doing to improve sustainability and provides important information to other organizations about the strategies that these water agencies have used to achieve their goals.

Inland Empire Utilities Agency is a leader in best-in-class projects and initiatives that range from green buildings and energy efficient systems and operations, to innovative environmental and resource management strategies. The Agency has become the leader in recycled water production in California as it accelerated development of its infrastructure so that all recycled water produced through its wastewater treatment activities can be beneficially used.

IEUA Headquarters
Inland Empire Utilities Agency's LEED headquarters.

Sonoma County Water Agency pledged to eliminate its carbon footprint by 2015 through its Carbon Free Water effort. The Agency has taken several steps towards its goal including: improving energy efficiency, using hybrid vehicles into its fleet, installing three solar projects, conducting ongoing studies of alternative energy generation options, and co-founding a county-wide financing mechanism to spur investment in efficiency and renewable energy for existing homes and buildings.

SCWA Solar
Sonoma County Water Agency’s solar panels.