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April 26, 2018
By: Leslie Crenna, Senior Writer
The water–energy nexus flowed through the presentations and conversations at the annual 2018 UC Davis Energy Affiliates Forum held April 19 at the Activities and Recreation Center on the UC Davis campus. Nearly 150 organizers, presenters, and participants were registered for the all-day event featuring keynote speaker Ron Nichols of Southern California Edison (SCE).
The common theme throughout the proceedings was the need for integrated solutions to meet the challenges posed by California’s rapid switch to renewable energy and statewide goals for a carbon neutral future. As the keynote and others emphasized, reliability is a critical challenge for our emerging energy systems, and integrated solutions — including demand management, load shifting, distributed assets, and energy portfolio diversification — must provide both redundancy and flexibility to meet these challenges head on.
Water Conservation Saves Energy: “The study demonstrated that the successful 24% water reductions achieved by urban water suppliers since 2013 also significantly reduced electricity usage by water system infrastructure.”
CWEE Director Professor Frank Loge spoke both in the morning and at the afternoon breakout session. Prof Loge’s remarks centered on the work of the Center for Water–Energy Efficiency, pronounced affectionately as “swee” by students and staff alike, and the goals of the affiliates program.
Taking center stage was CWEE’s recently completed study evaluating the electricity and greenhouse gas savings resulting from the governor’s 25% urban water conservation mandate during California’s most recent drought. The study demonstrated that the successful 24% water reductions achieved by urban water suppliers since 2013 also significantly reduced electricity usage by water system infrastructure. The details were eye opening: The electricity savings were found to be greater than those achieved by energy efficiency programs conducted by the investor-owned electricity utilities for roughly the same time period. Water efficiency programs were also found to be more cost effective in saving electricity than energy efficiency programs. The study demonstrated that the successful 24% water reductions achieved by urban water suppliers since 2013 also significantly reduced electricity usage by water system infrastructure.
Overall, California succeeded in saving 524,000 million gallons (MG) of water over the drought conservation mandate period which resulted in a savings of 1,830 GWh in electricity, and 521,000 metric tonnes of carbon dioxide equivalents (MT CO2e). CWEE Data Scientist Andrew Holguin created a simple way to display these results using a web-application dubbed “California H2Open”.
Prof. Loge cited the study as evidence that water and energy utilities should work together on policy changes that would allow energy efficiency funds to be used toward water conservation. Current California Public Utility Commission (CPUC) policies as well as the mismatch between energy and water service areas either prohibits or creates barriers to such an approach.
Prof. Loge also covered the beginning steps of a multi-year California Energy Commission (CEC)-funded project in partnership with the Moulton Niguel Water District and Helio Energy Solutions focused on energy demand management and load shifting within a water supply system. The work is driven by the mismatch between the traditional electricity supply-demand curve (and pricing) and the new reality of dramatically increasing and variable renewable energy supplies.
From a water-energy nexus perspective, the mismatch is reflected in the fact that water utilities are designed and incentivized to avoid operating pumps during the day when energy is seasonally in oversupply and being sold regionally at a loss.
Prof. Loge invited active participation from the affiliates in the afternoon session which sparked lively debate about the feasibility of implementing time-of-use or other specialized water rates and the need for collaboration around a common water-energy intensity calculation methodology to facilitate the flow of carbon cap and trade funds to the water utility sector. Affiliates raised concerns about barriers to innovative partnering between energy and water utilities like existing CPUC policies that don’t grant portfolio credits for collaborative efficiency and conservation programs.
Another CEC project on CWEE’s plate focuses on policy barriers to commercial use of recycled water. CWEE is working with Jackson Family Wines to perform on-site water reuse as part of winemaking process operations. Prof. Loge pointed out that while the requirements to recycle domestic wastewater are very clear, for greywater reuse and water reuse in the commercial and other sectors, “policy is the barrier to implementation.”
The driving force behind much of the work discussed over the course of the full day forum was outlined by Dave Peck, advisor to President Michael Picker of the CPUC: the California Renewable Portfolio Standard has set a 50% renewable energy retail sales goal by 2030.
Dale Roberts, Principal Engineer for the Sonoma County Water Agency (SCWA), reported on his “self-sufficient” water agency’s success in achieving a carbon free water system in 2015 for 600,000 customers throughout Sonoma and Marin counties. SCWA operates independently from the California Water Project.
Jim Price, Senior Advisor with the California Independent System Operator CAISO, spoke about curtailment, load shifting, and its role managing the energy imbalance market in an extended western regional scope.
Southern California Gas regional vice president of external affairs and environmental strategy George Minter emphasized the need to decarbonize our gas supply to comply with state mandates to capture 40 percent of methane by 2030. Minter expressed confidence in strategies such as capturing biomethane from waste streams and cited UC Davis studies that confirmed the feasibility of this approach.
For the midday poster session, newly hired Research Engineer, Robert Good, reported a high level of interest and engagement around the posters reflecting the Center’s work:
- Reducing Electricity Grid Imbalances through Energy Demand Management of Water Delivery Infrastructure
- Energy Intensity of Wholesale Water in California
- Onsite Non-Potable Water Recycling: Overcoming the Barriers
- California’s Urban Water Conservation Mandate Delivers Bonus Energy and Greenhouse Gas Savings
- Demonstrating the Potential for On-Site Electricity Generation from Food Waste Using Containerized Anaerobic Digestion Units
- Nexus of Beer, Water, and Energy: Case Study of a California Lager Microbrewery
- Water Energy Nexus in Informal Water Systems
CWEE is one of three centers that make up the Energy and Efficiency Institute, along with the Western Cooling Efficiency Center and the California Lighting Technology Center.