Hidden in the Water
California gets serious about tracking the energy costs embedded in water.
The most effective way to reduce energy related to water use is to consume less water—Energy Down the Drain (NRDC/Pacific Institute) 2004.
Water and power: two essential, interrelated resources. Water generates power, and electricity moves water, a relationship that has become so critical the Alliance to Save Energy, a coalition of business, government, and environmental leaders that promotes efficient and clean energy use worldwide, has coined the term “Watergy.”
In this country the symbiosis between water and power is most obvious in the West, and no more so than in California where 19% of the state’s electrical consumption and 30% of natural gas use are water related. The cost of transporting runoff from the Sierra Nevada to homes and businesses in Los Angeles amounts to 5 billion kWh a year, which makes the State Water Project (SWP) the single largest energy consumer in the state. To move just 1 acre-foot of the SWP south requires 3,000 kWh of energy.
The fact is that 60,000 potable water systems and 15,000 wastewater treatment systems nationwide account for more than 3% of the country’s annual electrical tab, 75 billion kWh each year. The energy goes to pump water from underground aquifers and deliver supplies from source to consumption. Treat, heat, or cool that water and add more to the energy total. The bad news is that a joint report issued by the Natural Resources Defense Council (NRDC) and Oakland-based Pacific Institute forecasts the amount of energy we’ll need to treat water will increase as new water-quality standards are initiated and new treatments to improve drinking-water taste and color are developed. Nor does the 3% figure include energy demands at the far end of the water cycle. In 1995, California alone used 1.6 billion kWh of electricity to treat its wastewater.
The water-power symbiosis was very much on the agenda at the November 2006 California Water Policy Conference where keynote speaker Tim Brick, the newly elected chief executive officer of the Southern California Metropolitan Water District, told the audience that energy is currently the biggest challenge confronting the state’s water industry. Other issues discussed around the three-day conference included direct install, time-of-use meters, and modeling water conservation after strategies developed by the state’s energy utilities.
Some action has already been taken. The California Public Utilities Commission (CPUC), which regulates the state’s privately owned water districts, issued its own Water Action Plan in 2005, calling for a 10% reduction in water-related energy consumption in the next three years. The public has also weighed in the form of a 2006 resolution of the state League of Women Voters, which recommends programs be developed to aid water providers in reducing their consumption of electric power and fossil fuels, as well as universal metering and economic incentives to shift water-related energy loads to off-peak hours.
But by far the biggest splash has been made by the NRDC/Pacific Institute’s 2004 report. Energy Down the Drain reminds both energy and water planners of what many have already acknowledged, that energy costs are embedded in all phases of the water cycle, from source and distribution through treatment to end use and wastewater management. Without coordinated planning, energy use will continue to spiral upward, economic and environmental costs will increase, and the state will be hard pressed to meet the requirements of AB 32, the far-reaching climate change legislation it passed last year.
According to NRDC Senior Policy Analyst Ronnie Cohen, the NRDC/Pacific Institute report caught the attention of the California Energy Commission (CEC), whose own follow-up analysis concluded that by pursuing water efficiencies the state could save all the energy in its 2006 to 2008 energy efficiency portfolio (the amount energy utilities intend to save for that period of time), and at a little more than half the cost. Further, the CEC directed the CPUC to pursue the question of how these savings might be achieved. On order from CPUC Commissioner Dian Grueneich, the state’s energy utilities submitted $10 million in pilot programs to be undertaken in cooperation with local water utilities to investigate how combined water and power efficiency can be accomplished. The proposals were submitted in mid-January 2007; review is scheduled for spring, and the goal is to have the pilots up and running by mid-year.
Cohen believes there’s a need for everyone to get onboard with a new paradigm for the water-energy relationship. “There are a variety of water industry programs that might not be cost-effective if you look at the water savings alone. But when you add the energy savings, these measures become very cost-effective.”
Given California’s varied topography, pumping consumes the largest chunk of energy consumed by municipal water systems, 170 KWh per acre-foot of delivered water, given a rate of 0.5 acre-foot and 2.6 people per household. In 2000, annual urban water use in California topped out at 7 million acre-feet, 4 million acre-feet of which went for household use. According to a study of 1,200 homes conducted in 14 cities nationwide by the American Water Works Association Research Foundation, 26.7% of household water goes to toilet flushing, 21.7% to washing clothes, 16.8 % for showers, and 15.7% to water flowing out of household taps. Outside the house, residential landscape irrigation is estimated to account for 40% of water use (although some estimates for California put that figure as high as 70%). More than half of the 2.5 million acre-feet of water used annually by California’s industrial/commercial/institutional sector goes to heat and cool water. Landscape irrigation accounts for a whopping 38% of the water used by business and industry.
To give managers a chance to assess how much energy is required to provide water for various applications, the NRDC/Pacific Institute researchers developed a model based on research conducted by Robert Wilkinson, director of the Water Policy Program at the University of California at Santa Barbara. “The goal,” says Gary Wolff, who with Cohen coauthored the 2004 report, “was a simple accounting procedure that systematically quantified the energy use implications of water management.” Tracking energy inputs during the five stages of the water use cycle, the model is designed to give planners and policymakers the opportunity to predict the relative energy impacts of their water policy choices. Because not all energy expended in the water cycle is electric—diesel fuel, for example, is used to pump water on farms and natural gas is typically used to heat water in urban settings—the researchers defined equivalent kilowatt-hours, which is the sum of actual kilowatt-hours and fossil fuel use converted to kilowatt-hours (assuming that the fuels were used in thermal power plants to produce electricity).
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San Diego was selected to model urban water use, in part because of the region’s dependence on imported water and because the San Diego County Water Authority (SDCWA) has been exploring sources for the 100,000 acre-feet a year of water it will need to meet future demand, the energy implications of which have not been explored. Water use was based on SDCWA projections for 2010 at 58% residential, 32% commercial/industrial/institutional, and 10% agricultural.
SDCWA buys its water from the Metropolitan Water District of Southern California (MWDSC), which supplies approximately 470,000 acre-feet a year from the Colorado River Aqueduct and 83,000 acre-feet a year from the State Water Project. The water is delivered from the SDCWA to its member agencies through two gravity-fed aqueducts of five large-diameter pipes each, and then from member agencies to retail customers through approximately 7,800 additional miles of pipe. Local groundwater provides about 30,000 acre-feet a year to the mix, with one brackish groundwater source treated to potable standards. Reclaimed water from wastewater treatment provides an additional 18,000 acre-feet of water a year. Surface water reservoirs are primarily used as terminal storage for imported water and amount to 86,000 acre-feet a year.
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The water in three of the five SDCWA pipelines is treated at a MWDSC plant in Riverside County while member agencies operate 10 local treatment plants. The member agencies also operate 14 wastewater treatment plants and 24 recycling facilities.
Prior to the NRDC/Pacific Institute study, the SDCWA had encouraged water conservation both directly, as a member of the California Urban Water Conservation Council, and as signatory to the council’s Memorandum of Understanding for Urban Water Conservation in California, which encourages water districts to seek partnerships with energy utilities. The SDCWA’s 10-year partnership with San Diego Gas and Electric resulted in the installation of more than 550,000 low-flow showerheads, and five years ago the two agencies partnered to offer financial incentives for installing horizontal-axis clothes washers. As a result of a year 2000 policy decision to reduce its dependence on potable water and particularly Colorado River water, the agency has also been working toward diversifying and expanding on local sources. Desalination of sea water has been a targeted option, specifically a reverse osmosis plant that would produce 56,000 acre-feet of fresh water a year, enough to meet approximately 8% of the region’s demand.
The most surprising result of the San Diego analysis, given the extended transport system through which the SDCWA’s water must pass to reach consumers, is that end use, not distribution, is the most energy-intensive segment in the water delivery chain. Additionally, despite the agency’s focus on desalination to meet future demand, wastewater recycling and conservation appear to be more energy-efficient sources of new water for the region. End-use energy intensity (the total amount of energy required to use a specific amount of water in a specific location), from heating water for showers to heating and cooling water for industrial use, amounted to 3,900 kWh per acre-foot of water consumed. Sources/conveyances followed as a not-too-close second at 2,040 kWh per acre-foot. Wastewater treatment used 570 kWh of energy per acre-foot, followed by distribution at 330 kWh an acre-foot, and finally water treatment at 60 kWh an acre-foot.
The San Diego case study highlights another obvious but not universally acknowledged dynamic of the water/energy equation, which is that saving water automatically saves energy, and end-use conservation eliminates all the upstream energy required to bring water to the point of use. Extending this observation to its logical conclusion, if the SDCWD were to rely on conservation to meet future water demand, it would reduce the overall energy intensity of its water supply by 13%. If it were to use seawater desalination to satisfy that demand, it would reduce energy intensity by less than half the projected savings from conservation. Using recycled water would reduce energy savings by 4%. Additionally, the energy savings from relying on conservation rather than additional State Water Project water to provide the SDCWA’s next 100,000 acre-feet of water would be approximately 767 million kWh, enough to provide power for 25% of San Diego’s households for a year. Using recycled water to meet future demand would save less than half that amount, or 348 million kWh.
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Another view of how end-use conservation reflects backward in the water supply chain is to consider the actual amounts of water that would have to be supplied (and the energy expended) if conservation were not selected as the demand option of choice. To compensate for the 7% that is typically lost in distribution and net 100,000 acre-feet of new water a year would require the generation of an additional 8,000 acre-feet from desalination or from recycling. The same 100,000 acre-feet would require an additional 13,000 acre-feet of additional imported water to compensate for the 5% lost in treatment.
Based on the San Diego modeling, the researchers conclude that urban conservation, particularly regarding such uses as clothes washers and commercial cooling towers, is important regardless of the source of water or the location of its use. Again, extending this observation to its logical conclusion, it would appear that policy actions that affect water use might have much larger energy implications than those that are intended to affect the mix of physical water sources, even when the water has to travel long distances. Simply put, once you add energy to the equation, water conservation has much stronger economic and environmental benefits than had typically been recognized. One of those benefits, Cohen reminds us, relates to climate change.
“Right now the California Air Resources Board is identifying early actions that can be accomplished in the next couple of years to help the state meet its AB 32 targets. We’re proposing water efficiency measures as some of these early actions. Just as we used to look at water efficiency as a way to save water, now the future is looking at water efficiency as a way to save water and energy and help reduce climate change.”
The question is, where do we go from here? As Cohen points out, although the NRDC/Pacific Institute report recommends state energy and environmental policies should be designed to provide consistent encouragement to invest in cost-effective energy and water demand-side strategies, there are currently no requirements that water agencies look at energy impacts in their decision-making. Recognizing the value of the NRDC model to managers across the state, Wolff applied for funds to develop a more user-friendly version of the original spreadsheet model used to generate the report. Once completed, the California Urban Conservation Council mailed the model and its user’s guide to each water district in California. In addition, both the model, now called the Water to Air Model (a version each for urban and agricultural water use), and the user manual are available through the Pacific Institute’s Web site.
The Santa Clara River Water District, a water wholesaler that serves the 1.7 million residents of Santa Clara County, including the city of San Jose, has applied the model to quantify energy savings from conservation programs implemented between fiscal years 1992–1993 and 2005–2006. The district considers that its mission includes management of the county’s water resources in a practical, cost-effective, and environmentally sensitive manner and because of this wanted to know how much carbon dioxide emission it saved as its contribution toward reducing global warming. The Santa Clara district imports half of its water (although because it’s located in northern California not over such long distances as San Diego), with the remainder coming from groundwater and surface supplies. “We have the water supply in our mind,” says Water Use Efficiency Manager Hossein Ashktorab, “but also the environmental benefits through water conservation and recycling.”
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Using a combination of the model’s default assumptions and its own data, the district determined that it had saved 1.42 billion kWh of electricity during the 13-year period through conservation and water recycling programs. Like San Diego, the district determined that end-use water conservation produced the most significant energy savings, 60%, more than the other four stages in the water chain combined. To date its partnership with its energy utility Pacific Gas and Electric (PG&E) has been focused mostly on hot water savings, but Ashktorab says the goal now will include programs that also conserve energy in cold water applications. In addition Ashktorab was also able to report to the district’s board of directors that conservation has saved over 335 million kilograms of carbon dioxide from being released into the environment during the same time period. “If you put all these benefits on top of the saved water,” says Ashktorab, “it becomes much more interesting, especially since our district considers environmental stewardship an important part of what we do. Our hope is that the results of the modeling will help us convince our board to provide more money for conservation.”
The CPUC’s pilots are designed to accomplish similar goals. In southern California, the Metropolitan Water District (MWD) will be partnering with local energy utilities to install high-efficiency toilets in low-income housing. “Low-income housing is often higher density,” says Tim Blair, MWD’s water use efficiency program manager. “The opportunity to save water is substantial in this kind of a situation because the economic incentives may not be sufficient to cause the desired change through rebates. On the energy side, the CPUC authorizes low-income programs that don’t have the same cost-effectiveness requirements as their other rebate programs. If the water and energy utilities can accomplish this program together, we might be able to reach true cost-effective thresholds in this hard-to-reach market.
“What’s important is that water ratepayers pay for the benefits that accrue to water utilities and energy ratepayers pay for benefits that accrue to the energy utilities. Partnership is important. Longstanding partnerships can arise when they produce greater benefits than could be achieved by either utility alone.” Another issue that Blair thinks is important is mutual understanding of the differences between the state’s largely municipal water utilities that are self-regulated and the investor-owned energy utilities, which answer to the CPUC and ratepayers. “Essentially I think this partnership is going to create the opportunity for shareholders to see the value of the return on their investment, while the people of the state of California will see their rates for both water and energy creating efficiencies that get them more reliable and cost-effective energy and water.”
In northern California, at PG&E, Gerry Hamilton thinks what’s needed is a scheme that’s workable and acceptable to the CPUC. “There’s never been a program that’s enables an investor-owned utility to claim embedded energy savings, water or otherwise.” Hamilton sees the energy-water utility pilots as providing “a safe platform” to experiment with how to measure and verify not only embedded energy costs in water but quantifying when energy is saved through water conservation. “If you can positively link, to a statistically significant level of confidence, how much energy there is in a gallon of water saved, you can link tangible energy savings to avoided water use, above and beyond heating or pumping. And if you can do this with a high level of confidence and a value can be assigned to however many watt- or kilowatt-hours are saved, this would provide a basis for spending public purpose dollars to avoid the consumption of those kilowatt-hours.”
Frank Spasaro, manager of energy efficiency partnerships for both Southern California Gas Co. and San Diego Gas and Electric, agrees. “We don’t know how to fit water conservation measures into our current system of cost-effectiveness tests to establish that ratepayer money is being spent prudently and cost-effectively. We are essentially moving forward on good faith—and because this makes sense—which is why we’re doing the pilot.” A tangible goal, says Spasaro, would be to bring water conservation into the next energy efficiency program, which begins in 2009.
“We need to establish differences at the micro level. There may be some areas where gravity is a factor in water delivery and saving water in such cases won’t have a significant energy impact.” There are also issues of what can be described as balancing who spends the money against who gets the credit, particularly in regard to air-quality issues. “If you save a gallon of water in San Diego but the energy is actually saved up in northern California in the PG&E service area, who should be paying for the water conservation?”
Author's Bio: Penelope B. Grenoble is a contributor to environmental publications.
May-June 2007
Hidden in the Water
California gets serious about tracking the energy costs embedded in water.
The most effective way to reduce energy related to water use is to consume less water—Energy Down the Drain (NRDC/Pacific Institute) 2004.
Water and power: two essential, interrelated resources. Water generates power, and electricity moves water, a relationship that has become so critical the Alliance to Save Energy, a coalition of business, government, and environmental leaders that promotes efficient and clean energy use worldwide, has coined the term “Watergy.”
In this country the symbiosis between water and power is most obvious in the West, and no more so than in California where 19% of the state’s electrical consumption and 30% of natural gas use are water related. The cost of transporting runoff from the Sierra Nevada to homes and businesses in Los Angeles amounts to 5 billion kWh a year, which makes the State Water Project (SWP) the single largest energy consumer in the state. To move just 1 acre-foot of the SWP south requires 3,000 kWh of energy.
The fact is that 60,000 potable water systems and 15,000 wastewater treatment systems nationwide account for more than 3% of the country’s annual electrical tab, 75 billion kWh each year. The energy goes to pump water from underground aquifers and deliver supplies from source to consumption. Treat, heat, or cool that water and add more to the energy total. The bad news is that a joint report issued by the Natural Resources Defense Council (NRDC) and Oakland-based Pacific Institute forecasts the amount of energy we’ll need to treat water will increase as new water-quality standards are initiated and new treatments to improve drinking-water taste and color are developed. Nor does the 3% figure include energy demands at the far end of the water cycle. In 1995, California alone used 1.6 billion kWh of electricity to treat its wastewater.
The water-power symbiosis was very much on the agenda at the November 2006 California Water Policy Conference where keynote speaker Tim Brick, the newly elected chief executive officer of the Southern California Metropolitan Water District, told the audience that energy is currently the biggest challenge confronting the state’s water industry. Other issues discussed around the three-day conference included direct install, time-of-use meters, and modeling water conservation after strategies developed by the state’s energy utilities.
Some action has already been taken. The California Public Utilities Commission (CPUC), which regulates the state’s privately owned water districts, issued its own Water Action Plan in 2005, calling for a 10% reduction in water-related energy consumption in the next three years. The public has also weighed in the form of a 2006 resolution of the state League of Women Voters, which recommends programs be developed to aid water providers in reducing their consumption of electric power and fossil fuels, as well as universal metering and economic incentives to shift water-related energy loads to off-peak hours.
But by far the biggest splash has been made by the NRDC/Pacific Institute’s 2004 report. Energy Down the Drain reminds both energy and water planners of what many have already acknowledged, that energy costs are embedded in all phases of the water cycle, from source and distribution through treatment to end use and wastewater management. Without coordinated planning, energy use will continue to spiral upward, economic and environmental costs will increase, and the state will be hard pressed to meet the requirements of AB 32, the far-reaching climate change legislation it passed last year.
According to NRDC Senior Policy Analyst Ronnie Cohen, the NRDC/Pacific Institute report caught the attention of the California Energy Commission (CEC), whose own follow-up analysis concluded that by pursuing water efficiencies the state could save all the energy in its 2006 to 2008 energy efficiency portfolio (the amount energy utilities intend to save for that period of time), and at a little more than half the cost. Further, the CEC directed the CPUC to pursue the question of how these savings might be achieved. On order from CPUC Commissioner Dian Grueneich, the state’s energy utilities submitted $10 million in pilot programs to be undertaken in cooperation with local water utilities to investigate how combined water and power efficiency can be accomplished. The proposals were submitted in mid-January 2007; review is scheduled for spring, and the goal is to have the pilots up and running by mid-year.
Cohen believes there’s a need for everyone to get onboard with a new paradigm for the water-energy relationship. “There are a variety of water industry programs that might not be cost-effective if you look at the water savings alone. But when you add the energy savings, these measures become very cost-effective.”
Given California’s varied topography, pumping consumes the largest chunk of energy consumed by municipal water systems, 170 KWh per acre-foot of delivered water, given a rate of 0.5 acre-foot and 2.6 people per household. In 2000, annual urban water use in California topped out at 7 million acre-feet, 4 million acre-feet of which went for household use. According to a study of 1,200 homes conducted in 14 cities nationwide by the American Water Works Association Research Foundation, 26.7% of household water goes to toilet flushing, 21.7% to washing clothes, 16.8 % for showers, and 15.7% to water flowing out of household taps. Outside the house, residential landscape irrigation is estimated to account for 40% of water use (although some estimates for California put that figure as high as 70%). More than half of the 2.5 million acre-feet of water used annually by California’s industrial/commercial/institutional sector goes to heat and cool water. Landscape irrigation accounts for a whopping 38% of the water used by business and industry.
To give managers a chance to assess how much energy is required to provide water for various applications, the NRDC/Pacific Institute researchers developed a model based on research conducted by Robert Wilkinson, director of the Water Policy Program at the University of California at Santa Barbara. “The goal,” says Gary Wolff, who with Cohen coauthored the 2004 report, “was a simple accounting procedure that systematically quantified the energy use implications of water management.” Tracking energy inputs during the five stages of the water use cycle, the model is designed to give planners and policymakers the opportunity to predict the relative energy impacts of their water policy choices. Because not all energy expended in the water cycle is electric—diesel fuel, for example, is used to pump water on farms and natural gas is typically used to heat water in urban settings—the researchers defined equivalent kilowatt-hours, which is the sum of actual kilowatt-hours and fossil fuel use converted to kilowatt-hours (assuming that the fuels were used in thermal power plants to produce electricity).
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San Diego was selected to model urban water use, in part because of the region’s dependence on imported water and because the San Diego County Water Authority (SDCWA) has been exploring sources for the 100,000 acre-feet a year of water it will need to meet future demand, the energy implications of which have not been explored. Water use was based on SDCWA projections for 2010 at 58% residential, 32% commercial/industrial/institutional, and 10% agricultural.
SDCWA buys its water from the Metropolitan Water District of Southern California (MWDSC), which supplies approximately 470,000 acre-feet a year from the Colorado River Aqueduct and 83,000 acre-feet a year from the State Water Project. The water is delivered from the SDCWA to its member agencies through two gravity-fed aqueducts of five large-diameter pipes each, and then from member agencies to retail customers through approximately 7,800 additional miles of pipe. Local groundwater provides about 30,000 acre-feet a year to the mix, with one brackish groundwater source treated to potable standards. Reclaimed water from wastewater treatment provides an additional 18,000 acre-feet of water a year. Surface water reservoirs are primarily used as terminal storage for imported water and amount to 86,000 acre-feet a year.
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The water in three of the five SDCWA pipelines is treated at a MWDSC plant in Riverside County while member agencies operate 10 local treatment plants. The member agencies also operate 14 wastewater treatment plants and 24 recycling facilities.
Prior to the NRDC/Pacific Institute study, the SDCWA had encouraged water conservation both directly, as a member of the California Urban Water Conservation Council, and as signatory to the council’s Memorandum of Understanding for Urban Water Conservation in California, which encourages water districts to seek partnerships with energy utilities. The SDCWA’s 10-year partnership with San Diego Gas and Electric resulted in the installation of more than 550,000 low-flow showerheads, and five years ago the two agencies partnered to offer financial incentives for installing horizontal-axis clothes washers. As a result of a year 2000 policy decision to reduce its dependence on potable water and particularly Colorado River water, the agency has also been working toward diversifying and expanding on local sources. Desalination of sea water has been a targeted option, specifically a reverse osmosis plant that would produce 56,000 acre-feet of fresh water a year, enough to meet approximately 8% of the region’s demand.
The most surprising result of the San Diego analysis, given the extended transport system through which the SDCWA’s water must pass to reach consumers, is that end use, not distribution, is the most energy-intensive segment in the water delivery chain. Additionally, despite the agency’s focus on desalination to meet future demand, wastewater recycling and conservation appear to be more energy-efficient sources of new water for the region. End-use energy intensity (the total amount of energy required to use a specific amount of water in a specific location), from heating water for showers to heating and cooling water for industrial use, amounted to 3,900 kWh per acre-foot of water consumed. Sources/conveyances followed as a not-too-close second at 2,040 kWh per acre-foot. Wastewater treatment used 570 kWh of energy per acre-foot, followed by distribution at 330 kWh an acre-foot, and finally water treatment at 60 kWh an acre-foot.
The San Diego case study highlights another obvious but not universally acknowledged dynamic of the water/energy equation, which is that saving water automatically saves energy, and end-use conservation eliminates all the upstream energy required to bring water to the point of use. Extending this observation to its logical conclusion, if the SDCWD were to rely on conservation to meet future water demand, it would reduce the overall energy intensity of its water supply by 13%. If it were to use seawater desalination to satisfy that demand, it would reduce energy intensity by less than half the projected savings from conservation. Using recycled water would reduce energy savings by 4%. Additionally, the energy savings from relying on conservation rather than additional State Water Project water to provide the SDCWA’s next 100,000 acre-feet of water would be approximately 767 million kWh, enough to provide power for 25% of San Diego’s households for a year. Using recycled water to meet future demand would save less than half that amount, or 348 million kWh.
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Another view of how end-use conservation reflects backward in the water supply chain is to consider the actual amounts of water that would have to be supplied (and the energy expended) if conservation were not selected as the demand option of choice. To compensate for the 7% that is typically lost in distribution and net 100,000 acre-feet of new water a year would require the generation of an additional 8,000 acre-feet from desalination or from recycling. The same 100,000 acre-feet would require an additional 13,000 acre-feet of additional imported water to compensate for the 5% lost in treatment.
Based on the San Diego modeling, the researchers conclude that urban conservation, particularly regarding such uses as clothes washers and commercial cooling towers, is important regardless of the source of water or the location of its use. Again, extending this observation to its logical conclusion, it would appear that policy actions that affect water use might have much larger energy implications than those that are intended to affect the mix of physical water sources, even when the water has to travel long distances. Simply put, once you add energy to the equation, water conservation has much stronger economic and environmental benefits than had typically been recognized. One of those benefits, Cohen reminds us, relates to climate change.
“Right now the California Air Resources Board is identifying early actions that can be accomplished in the next couple of years to help the state meet its AB 32 targets. We’re proposing water efficiency measures as some of these early actions. Just as we used to look at water efficiency as a way to save water, now the future is looking at water efficiency as a way to save water and energy and help reduce climate change.”
The question is, where do we go from here? As Cohen points out, although the NRDC/Pacific Institute report recommends state energy and environmental policies should be designed to provide consistent encouragement to invest in cost-effective energy and water demand-side strategies, there are currently no requirements that water agencies look at energy impacts in their decision-making. Recognizing the value of the NRDC model to managers across the state, Wolff applied for funds to develop a more user-friendly version of the original spreadsheet model used to generate the report. Once completed, the California Urban Conservation Council mailed the model and its user’s guide to each water district in California. In addition, both the model, now called the Water to Air Model (a version each for urban and agricultural water use), and the user manual are available through the Pacific Institute’s Web site.
The Santa Clara River Water District, a water wholesaler that serves the 1.7 million residents of Santa Clara County, including the city of San Jose, has applied the model to quantify energy savings from conservation programs implemented between fiscal years 1992–1993 and 2005–2006. The district considers that its mission includes management of the county’s water resources in a practical, cost-effective, and environmentally sensitive manner and because of this wanted to know how much carbon dioxide emission it saved as its contribution toward reducing global warming. The Santa Clara district imports half of its water (although because it’s located in northern California not over such long distances as San Diego), with the remainder coming from groundwater and surface supplies. “We have the water supply in our mind,” says Water Use Efficiency Manager Hossein Ashktorab, “but also the environmental benefits through water conservation and recycling.”
| | |
| |
Using a combination of the model’s default assumptions and its own data, the district determined that it had saved 1.42 billion kWh of electricity during the 13-year period through conservation and water recycling programs. Like San Diego, the district determined that end-use water conservation produced the most significant energy savings, 60%, more than the other four stages in the water chain combined. To date its partnership with its energy utility Pacific Gas and Electric (PG&E) has been focused mostly on hot water savings, but Ashktorab says the goal now will include programs that also conserve energy in cold water applications. In addition Ashktorab was also able to report to the district’s board of directors that conservation has saved over 335 million kilograms of carbon dioxide from being released into the environment during the same time period. “If you put all these benefits on top of the saved water,” says Ashktorab, “it becomes much more interesting, especially since our district considers environmental stewardship an important part of what we do. Our hope is that the results of the modeling will help us convince our board to provide more money for conservation.”
The CPUC’s pilots are designed to accomplish similar goals. In southern California, the Metropolitan Water District (MWD) will be partnering with local energy utilities to install high-efficiency toilets in low-income housing. “Low-income housing is often higher density,” says Tim Blair, MWD’s water use efficiency program manager. “The opportunity to save water is substantial in this kind of a situation because the economic incentives may not be sufficient to cause the desired change through rebates. On the energy side, the CPUC authorizes low-income programs that don’t have the same cost-effectiveness requirements as their other rebate programs. If the water and energy utilities can accomplish this program together, we might be able to reach true cost-effective thresholds in this hard-to-reach market.
“What’s important is that water ratepayers pay for the benefits that accrue to water utilities and energy ratepayers pay for benefits that accrue to the energy utilities. Partnership is important. Longstanding partnerships can arise when they produce greater benefits than could be achieved by either utility alone.” Another issue that Blair thinks is important is mutual understanding of the differences between the state’s largely municipal water utilities that are self-regulated and the investor-owned energy utilities, which answer to the CPUC and ratepayers. “Essentially I think this partnership is going to create the opportunity for shareholders to see the value of the return on their investment, while the people of the state of California will see their rates for both water and energy creating efficiencies that get them more reliable and cost-effective energy and water.”
In northern California, at PG&E, Gerry Hamilton thinks what’s needed is a scheme that’s workable and acceptable to the CPUC. “There’s never been a program that’s enables an investor-owned utility to claim embedded energy savings, water or otherwise.” Hamilton sees the energy-water utility pilots as providing “a safe platform” to experiment with how to measure and verify not only embedded energy costs in water but quantifying when energy is saved through water conservation. “If you can positively link, to a statistically significant level of confidence, how much energy there is in a gallon of water saved, you can link tangible energy savings to avoided water use, above and beyond heating or pumping. And if you can do this with a high level of confidence and a value can be assigned to however many watt- or kilowatt-hours are saved, this would provide a basis for spending public purpose dollars to avoid the consumption of those kilowatt-hours.”
Frank Spasaro, manager of energy efficiency partnerships for both Southern California Gas Co. and San Diego Gas and Electric, agrees. “We don’t know how to fit water conservation measures into our current system of cost-effectiveness tests to establish that ratepayer money is being spent prudently and cost-effectively. We are essentially moving forward on good faith—and because this makes sense—which is why we’re doing the pilot.” A tangible goal, says Spasaro, would be to bring water conservation into the next energy efficiency program, which begins in 2009.
“We need to establish differences at the micro level. There may be some areas where gravity is a factor in water delivery and saving water in such cases won’t have a significant energy impact.” There are also issues of what can be described as balancing who spends the money against who gets the credit, particularly in regard to air-quality issues. “If you save a gallon of water in San Diego but the energy is actually saved up in northern California in the PG&E service area, who should be paying for the water conservation?”