Energizing Water Efficiency: California Energy Sector Experiences Can Advance State’s Water Conservation and Efficiency

Pacific Institute | December 29th, 2013

As a dry December accentuates the stress on California’s limited water supplies, the success of the state’s energy sector in implementing efficiency programs offers v

As a dry December accentuates the stress on California’s limited water supplies, the success of the state’s energy sector in implementing efficiency programs offers valuable lessons to the water sector. A new report from the Pacific Institute examines the rules, regulations, and policies that promote energy efficiency and finds models for water management in drivers like the energy sector’s appliance standards, building codes, pricing policies, and utility-sponsored efficiency programs. California has made remarkable improvements in energy efficiency over the last several decades and is recognized as a national leader. The state’s per capita electricity and natural gas consumption is about 45% and 30% less, respectively, than other Americans. Indeed, California’s per capita electricity consumption has remained largely unchanged since the mid-1970s – while increasing by more than 50% across the U.S.  Efficiency policies, including incentive and education programs, have been a major factor in reducing per capita energy use in California. In water conservation and efficiency, California has also made major advances. Many urban areas across the state, including Los Angeles and San Francisco, are serving a larger population with the same or even less water than 20 years ago. But with increasing pressure on water supply from population and economic growth, the need to restore freshwater ecosystems, and climate change, greater water conservation and efficiency are essential. “Reductions in per-capita water demand have been driven first by a shift to a less water-intensive service-oriented economy, and second by federal, state, and local policies as well as utility programs facilitating water-efficiency improvements,” said Heather Cooley, co-director of the Pacific Institute Water Program. “We must examine new approaches for achieving even greater savings to address the water challenges we now face.” The Pacific Institute report identifies programs that have worked for the energy sector and offers recommendations for how they could be adapted to the water sector. First among them are to continuously update standards and codes for fixtures and buildings to capture new technologies and practices.

Energy and water co-benefits from covering canals with solar panels

Nature Portfolio (Springer Nature) | March 18th, 2021

Solar power development over canals is an emerging response to the energy–water–food nexus that can result in multiple benefits for water and energy infrastructure. C

Solar power development over canals is an emerging response to the energy–water–food nexus that can result in multiple benefits for water and energy infrastructure. Case studies of over-canal solar photovoltaic arrays have demonstrated enhanced photovoltaic performance due to the cooler microclimate next to the canal. In addition, shade from the photovoltaic panels has been shown to mitigate evaporation and potentially mitigate aquatic weed growth. However, the evaporation savings and financial co-benefits have not been quantified across major canal systems. Here we use regional hydrologic and techno-economic simulations of solar photovoltaic panels covering California’s 6,350 km canal network, which is the world’s largest conveyance system and covers a wide range of climates, insolation rates and water costs. We find that over-canal solar could reduce annual evaporation by an average of 39 ± 12 thousand m3 per km of canal. Furthermore, the financial benefits from shading the canals outweigh the added costs of the cable-support structures required to span the canals. The net present value of over-canal solar exceeds conventional overground solar by 20–50%, challenging the convention of leaving canals uncovered and calling into question our understanding of the most economic locations for solar power.

Energy Down the Drain: The Hidden Costs of California’s Water Supply

Pacific Institute | August 24th, 2004

As California’s electricity demand sets record highs and the Southwest is parched by drought, Energy Down the Drain: The Hidden Cost of California’s Water Supply b

As California’s electricity demand sets record highs and the Southwest is parched by drought, Energy Down the Drain: The Hidden Cost of California’s Water Supply by the Pacific Institute and the NRDC shows the hidden connection between energy and water. “With power shortages and a water scarcity a constant threat across the West, it’s time to look at water and energy in a new way,” said Dr. Gary Wolff a co-author of the report and Principal Economist and Engineer with the Pacific Institute. “But too often, policymakers and water and energy experts ignore the links. The good news is we can reduce our energy use, cut air pollution and create new energy supplies with cost-effective improvements to water efficiency.”

Energy Down the Drain. The Hidden Costs of California's Water Supply

Natural Resources Defense Council (NRDC) | August 2nd, 2004

California has been through its share of scorching droughts and energy shortages, but many residents of the western United States may not realize the close con- n

California has been through its share of scorching droughts and energy shortages, but many residents of the western United States may not realize the close con- nections between water and power resources. Water utilities use large amounts of energy to treat and deliver water. Even after utilities deliver water, consumers burn more energy to heat, cool, and use the water. The California State Water Project is the largest single user of energy in California. In the process of delivering water from the San Francisco Bay-Delta to Southern California, the project uses 2 to 3 percent of all electricity consumed in the state. The State Water Project burns energy pumping water 2,000 feet over the Tehachapi Mountains—the highest lift of any water system in the world. The amount of energy used to deliver that water to residential customers in Southern California is equivalent to approximately one-third of the total average household electric use in the region. Ninety percent of all electricity used on farms is devoted to pumping groundwater for irrigation.

Energy production and water savings from floating solar photovoltaics on global reservoirs

Nature Portfolio (Springer Nature) | March 13th, 2023

Growing global energy use and the adoption of sustainability goals to limit carbon emissions from fossil fuel burning are increasing the demand for clean energy, includin

Growing global energy use and the adoption of sustainability goals to limit carbon emissions from fossil fuel burning are increasing the demand for clean energy, including solar. Floating photovoltaic (FPV) systems on reservoirs are advantageous over traditional ground-mounted solar systems in terms of land conservation, efficiency improvement and water loss reduction. Here, based on multiple reservoir databases and a realistic climate-driven photovoltaic system simulation, we estimate the practical potential electricity generation for FPV systems with a 30% coverage on 114,555 global reservoirs is 9,434 ± 29 TWh yr−1. Considering the proximity of most reservoirs to population centres and the potential to develop dedicated local power systems, we find that 6,256 communities and/or cities in 124 countries, including 154 metropolises, could be self-sufficient with local FPV plants. Also beneficial to FPV worldwide is that the reduced annual evaporation could conserve 106 ± 1 km3 of water. Our analysis points to the huge potential of FPV systems on reservoirs, but additional studies are needed to assess the potential long-term consequences of large systems.

Estimated ground-water discharge by evapotranspiration from Death Valley, California

U.S. Geological Survey (USGS) | July 1st, 2003

Estuary News, October 2021

San Francisco Estuary Partnership (SFEP) | October 15th, 2021

Feather River Hydrologic Observatory: Improving Hydrological Snowpack Forecasting for Hydropower Generation Using Intelligent Information Systems

California Energy Commission (CEC) | August 31st, 2018

Changing climatic conditions and a lack of representative snow cover data challenge the ability to accurately model and fully utilize the water resources of montane snowp

Changing climatic conditions and a lack of representative snow cover data challenge the ability to accurately model and fully utilize the water resources of montane snowpack on which California depends. This project aims to improve scientific understanding of snowpack modeling and streamflow forecasting techniques. Though relevant across industries and the state, this research focuses on hydropower applications in the North Fork of the Feather River. Central components of the project are four wireless sensor networks, installed in locations that are representative of vegetation and topography patterns across the basin. The networks collect snow, temperature, relative humidity, soil moisture, and soil temperature data every 15 minutes. By blending this information with remote sensing data and historical maps, we estimate the spatial distribution of snow water resources at high resolution. These outputs can help improve runoff forecasting tools such as the Precipitation-Runoff Modeling System (PRMS). Preliminary results show that wireless sensor networks can successfully track hydrologic states and fluxes in real time and provide a more representative picture of snowpack accumulation and melt than traditional index stations. Network data are also used to gain insight into rain-on-snow events, which are a key streamflow generation mechanism for the Feather River. The data show that the current calibration of PRMS on the Feather River could overestimate snowfall and underestimate liquid precipitation. Future steps include a sensitivity analysis of PRMS to identify its dominant parameters and conceptual limitations, as well as a full, dynamic recalibration of the model. Blended maps of snow water equivalent will also be assimilated into the model. These results will be included in the decision-support suite for PG&E, California’s largest electric and natural gas utility, and an analysis will be performed to assess results’ economic value for stakeholders in the energy and water-supply sectors. 

From wastewater treatment plants to decentralized resource factories

Nature Portfolio (Springer Nature) | June 10th, 2024

Geohydrology and Evapotranspiration at Franklin Lake Playa, Inyo County, California

U.S. Geological Survey (USGS) | July 1st, 1997