The Embedded Energy of Water: Results of Innovative California Pilot Programs Released

Blog Post | December 22, 2010 - 2:32 pm
By Eric Mackres, Manager, Local Policy and Community Strategies

Acting on the nexus between energy and water can contribute to creating efficient and livable communities. Examples of opportunities include energy and water equipment efficiency standards and local programs that co-promote electric, natural gas, and water savings.  But this coordination between energy and water utilities has to date been very informal and as a result many opportunities slip between the cracks.  Energy and water savings can be dramatically increased if these two communities are encouraged to work more closely together and are rewarded appropriately for success. These issues are particularly timely because of growing political interest in joint energy and water issues including at the federal, state, and local level, particularly in localities that are facing water constraints.  In addition, energy and water utilities are looking for greater efficiency savings, but in a manner that minimizes costs.  Joint energy and water programs can provide these savings in a cost-efficient manner. 

An example of successful applied research in this area are the nine Embedded Energy in Water Pilot programs approved by the California Public Utilities Commission (CPUC) and implemented by the state's investor-owned utilities (IOUs), Pacific Gas and Electric Company (PG&E), Southern California Edison (SCE), and San Diego Gas and Electric Company (SDG&E) from July 2008-December 2009.  A draft evaluation report [PDF Report] [PDF Appendices] of these programs was released this month and CPUC will be hosting a webinar to present the results on January 5, 2011.  According to pages iv-v of the report, the key findings include:

  1. SCE’s Leak Detection program appears to offer the greatest energy savings potential (at relatively low cost) among all the Pilot programs. In particular, the energy savings documented in this report are based on leaks that were actually repaired during the program period; potential achievable water (and energy) savings were estimated to be much higher by the program implementation contractor.
  2. PG&E and SDG&E detention facility projects that installed efficient toilets, urinals, and toilet flush timers generated high energy savings. Future programs may seek to focus on these types of projects, pending detailed cost-effectiveness analyses. (For these projects, SDGE&E contributed capital funding whereas PG&E offered rebates based on water savings.)
  3. Recycled water retrofit projects can offer large potable water savings, but additional research is needed on the IOU embedded energy in recycled water treatment (which offsets energy savings from potable water). In areas where recycled water treatment does not require significant IOU energy, it may be possible to design cost-effective programs based on potable water savings.
  4. The other programs do not initially appear to be cost-effective, even where embedded energy savings are incomplete (e.g., wastewater for PG&E high efficiency toilets). That said, additional research is needed on actual program spending and potential changes in end-user energy (e.g., new motors, reduced hot water). Cost-effectiveness could be increased by reducing energy IOU program funding levels and/or targeting programs to the most energy-intensive water systems (e.g., Lake Arrowhead).  

As the work of the CPUC and others has clearly established the opportunity for cost-effective joint energy and water efficiency programs, it is now time to move this work from informal to more formal coordination.   Two weeks ago ACEEE and the Alliance for Water Efficiency (AWE) hosted a workshop, with funding from the Turner Foundation, bringing together leaders from both the energy efficiency and water efficiency fields.  This meeting was the kick-off of a process to develop a blueprint and joint agenda to highlight shared priorities on policy, programs, and research that will extend into 2011.  Over the next few months ACEEE and AWE will synthesize the discussions from the workshop and present a draft blueprint for collaboration to stakeholders in both fields.  The finalized blueprint will provide a consensus path for collaboration on issues of shared interest over the coming years.