Today’s post is a follow-up of yesterday’s post about Dr. Chu’s talk, debating whether I misunderstood his statement “that 22% of California’s electricity goes to moving water.” The source is no longer available online, and most likely it is a fraction of that, but the subject is important enough to do some further digging. If any readers here have expertise on this subject, please enlighten us with your knowledge in the comments below.
Though it is raining today in Southern California, we all know about the terrible drought conditions in the state which supplies much of our nation with real food – food that actually shows up on our dinner table every day. We should all be concerned. They produce 99 percent of this nation’s almonds and walnuts, 92 percent of this nation’s strawberries, and 90 percent of this nation’s tomatoes.
The more that California experiences a severe drought, the more temptation there could be to move water around, and that comes at a huge energy cost, which enters a vicious cycle, because it takes a lot of water to produce energy. Likewise, desalination can also be used to produce more of their water, but only by using enormous amounts of energy.
I found a great resource paper from 2004 – the NRDC wrote a publication titled “Energy down the drain – the hidden costs of California’s water supply.”
The following is an excerpt from that paper concerning energy use in moving California’s water around:
FROM SOURCE TO TAP: THE HIGH ENERGY COST OF MOVING WATER
Moving large quantities of water over long distances and significant elevations is a highly energy intensive task. For this reason, water systems in the West are particularly energy intensive. According to the Association of California Water Agencies, water agencies account for 7 percent of California’s energy consumption and 5 percent of the summer peak demand.
The State Water Project (SWP) is the largest single user of energy in California. It consumes an average of 5 billion kWh/yr, more than 25 percent of the total electricity consumption for the entire state of New Mexico. The California Energy Commission reports that SWP energy use accounts for 2 to 3 percent of all electricity consumed in California.
The SWP consumes so much energy because of where it sends its water. To convey water to Southern California from the Sacramento–San Joaquin Delta, the SWP must pump it 2,000 feet over the Tehachapi Mountains, the highest lift of any water system in the world. Pumping one acre-foot of SWP water to the region requires approximately 3,000 kWh. Southern California’s other major source of imported water is also energy intensive: pumping one acre-foot of Colorado River Aqueduct water to Southern California requires about 2,000 kWh.
In fact, according to an estimate from the Metropolitan Water District of Southern California, the amount of electricity used to deliver water to residential customers in Southern California is equal to one-third of the total average household electric use in Southern California.
Note that the California State Water Project supplies water to two-thirds of California’s population. 70% of the water goes to urban users and 30% to agriculture.
Obviously, to answer the question in this post’s title, there is great variance from North to South and from East to West across the large state of California. In this next quote, the NRDC paper discusses the distorted low-cost of irrigation water provided by policy.
“It is difficult to calculate the full value of the subsidies given to users of federally supplied irrigation water. This difficulty helps keep the energy costs of water systems buried. Many California farmers still pay the government $2 to $20 per acre-foot for water, which represents as little as 10 percent of the “full cost” of the water, although some farmers are paying more as contracts are revised (e.g., $35 per acre-foot) For new projects built or proposed by the Bureau of Reclamation, water costs are between $250 and $500 per acre-foot.”
The NRDC then describes how opportunists use this cheaply available water for irrigation in a power arbitrage scheme, by selling hydropower at a substantial profit, and further reducing incentives to conserve the cheap water supplied to irrigators.
These issues become complex and convoluted once policy is taken into account.
As for farms specifically, the NRDC paper sums up water use by farms in California, “Ninety percent of all electricity used on farms is devoted to pumping groundwater for irrigation.”
In the Western arid climates where so many people prefer to live, the goal of developers is to supply water from a more water abundant location even if that means pumping it over a big elevation incline, which tremendously increases the energy required to supply the water. Often, these energy costs are overlooked in project planning phases.
I can give you a perfect example of an insane project such as this here in my arid Western state of Colorado. Without a lot of fanfare, a big water project named the “$1 billion Southern Delivery System” began in 2010 which is to pump water uphill through a 53-mile pipeline from Pueblo to Colorado Springs. Obviously, the rapid population growth of Colorado Springs required desperate measures in attempt “not to constrain” growth, and Colorado Springs had the water rights for the project so couldn’t resist. Though environmental groups signed off, they admitted that the huge energy requirements to pump the water uphill are a “greenhouse issue”. If you read about the project there are huge costs involved -including things that you might not think of- like roads and ranchers left high and dry, yet, many are benefiting economically during the construction phase, and there are those who will benefit from the increased availability of water in the Springs. Is it worth it to “not constrain” population growth? The Southern Delivery System’s website states, “Water is the lifeblood of our economic health, and critical to retaining and attracting jobs and business to our region.” I have to wonder how Springs residents feel about paying more for their water to pave the way for more residents in their city.
So, back to the question raised by yesterday’s post. What percent of energy used by the state of California is used to move water?
I wish I knew.
Blogger Dan Brekke summarizes the 2005 California Energy Commission report, “California’s Water – Energy Relationship” in a pie chart here, which would suggest that the amount of electricity used to move water in California is 4.2 percent of its total electrical use, or 48,000 GWh. This is too low, however, because irrigation is put into a separate category and I’d think it should be included as “moving water”, too. Also, more recent studies and papers since the 2005 California Energy Commission’s paper say that the Commission’s estimates were too low; and, that earlier studies overall have been using assumptions which have been too conservative.
(To view yesterday’s post about Chu’s talk, click here.)
About the photo: The Hayfield Pump Lift – photo and description by Chuck Coker @ FlickCC. The Hayfield Pump Lift is part of the Colorado River Aqueduct. The aqueduct carries water from the Colorado River across the Mojave Desert to Los Angeles, California. It is one of three major aqueduct systems that supply water to Los Angeles. The Colorado River Aqueduct carries water 242 miles from Lake Havasu on the Colorado River to Lake Matthews in western Riverside County. It was built by the Metropolitan Water District Commission. It took eight years to build the aqueduct, from 1934 to 1941. The water is lifted 1,617 feet as it passes through five pump lifts. The aqueduct has 92 miles of tunnels, 63 miles of concrete canals, 55 miles of concrete conduits, and 144 siphons. (That adds up to 210 miles. I don’t know what the other 32 miles is made up of.) The Hayfield Pump Lift lifts the water 440 feet. It can be found on the north side of Interstate 10 between Chiriaco Summit and Desert Center, California.
For another great photo see this.