When most of us think of slowing global warming, we think of reducing car exhaust and power plant emissions – limiting activities that involve combusting fossil fuels. But we rarely draw the connection between the production of energy and another important resource: water.
Yet in California, 20% of the state’s electricity and 30% of the natural gas that isn’t used by power plants goes to the water system – from pumping it for delivery to disposing of wastewater. Could saving water play a significant role in addressing climate change? And, if so, could we achieve these savings without incurring significant costs?
A bill just signed by governor Jerry Brown will pave the way to answer those key questions. The Water-Energy Nexus Registry bill, or SB 1425, establishes a voluntary registry of greenhouse gas emissions for water utilities to account for the emissions generated from their energy use. It’s a radical departure of how California has been addressing climate change. In effect, SB 1425 moves the focus from fossil fuels to water.
California has long been a leader in addressing global warming. In 2006, California enacted the Global Warming Solutions Act (AB 32), which set out to reduce emissions to 1990 levels by 2020. Since then, the state has implemented a flurry of programs to cut emissions, from subsidizing electric cars and solar panel purchases to mandating tailpipe emission reductions of cars and trucks. In September, the governor expanded the target by signing a bill requiring the state to cut the emissions to 40% below 1990 levels by 2030.
These programs have been a great success: California is on target to meet its near-term 2020 goal. Reaching the 2030 goal will require new investments and innovation.
The new registry for water-related emissions can play a key role in achieving that 2030 target. We haven’t been focusing on water primarily because our efforts have centered on reducing emissions from two of the biggest sources: burning fossil fuels to generate electricity and power vehicles. Then, the ongoing drought that first hit California five years ago put a spotlight on water consumption and its heavy reliance on the state’s electricity generation and distribution system.
The drought led to mandatory water use reductions, sparked public anger at heavy water users such as farmers and big businesses and touched off fights over water rights. For example, Nestle drew public outcry for continuing to pump and bottle millions of gallons of water.
I think many of us understand that driving less can significantly reduce emissions, but is that true for using less water?
To investigate this issue, I challenged my research group in the Center for Water-Energy Efficiency at the University of California, Davis, to explore how much electricity is saved through aggressive water conservation measures. The results shocked us.
Our analysis showed that the quantity of electricity saved statewide through reducing urban water use by 25% in 2015 was roughly equivalent to all of the electricity saved by all of the energy efficiency programs from the state’s four major investor-owned energy utilities in 2015. The conclusion: energy savings from water conservation are significant.
Our research focused on the so-called cold water energy, which is used for pumping, treating, and delivering water and disposing of wastewater. The energy used in consuming water, such as heating it, is commonly referred to as hot water energy.
To create effective water conservation programs, we will need good data to measure emission reductions associated with energy savings. SB 1425 will lay the groundwork for establishing a protocol to calculate energy-related emissions and create a registry for documenting and archiving them.
Making a strong connection between energy and water savings will also help persuade policy makers to fund more water conservation efforts. This, in turn, will also nudge water utilities to share their data with the voluntary registry. Otherwise, water utilities will either raise water rates to fund those initiatives or absorb the expenses themselves. As a result, they can become reluctant to step up voluntary conservation efforts. To meet the 2015 state mandate to reduce urban water use by 25% over the 2013 levels, for example, water utilities had to pay, on average, $75 for every acre-foot saved.
Instead of crafting new incentive programs, the state can use existing ones to fund water conservation efforts that also lower the state’s energy consumption. One of California’s most important climate change programs is the cap-and-trade system, which generates revenues for the state through the sale of permits that major polluters must buy to cover their emissions. The cap-and-trade program currently funds a variety of emissions-reducing efforts, including rebates for more energy- efficient water heaters. It doesn’t subsidize any type of cold-water conservation, and it should.
Just as we are encouraged to diversify our retirement accounts to ensure resiliency and make a profit, we must do the same in our strategies to lower the state’s emissions. Water utilities need to see conservation as an activity that does not threaten their fiscal stability, and we need their help to tackle climate change. In my view, energy utilities need to be even more aggressive investing in energy efficiency through water conservation, and California needs to expand its climate change programs to invest aggressively in both hot and cold water conservation. SB 1425 will help to get this done.
Frank Loge is the director of the Center for Water-Energy Efficiency and holds the Krone Endowed Professorship in the department of civil and environmental engineering at the University of California, Davis.