The idea of installing smart water meters is in vogue these days, with the idea that water users, if made more aware of how much water they’re using all the time (rather than just when they get their monthly bills), will use less:
In the spring of 2005, the City of Aurora, Colorado offered residents the opportunity to purchase Water Smart Readers (WSR). WSR are monitoring devices that provide households with real-time information on water consumption but not price information. The hope of this policy, from the utility?s perspective, was to make households more aware of their water consumption leading to, ideally, a reduction in water use. Real-time information policies are becoming more common as part of larger efforts by utilities to improve system-wide efficiency and more effectively manage demand.
That’s Aaron Strong and Chris Goemans in a weirdly counter-intuitive (to me at least) new paper, The impact of real-time quantity information on residential water demand. This seems obvious to me, that more information will make us smarter and therefore efficient water consumers.
Not so, Strong and Goemans found in their review of the Aurora data. Smart meters tended to increase water use in Aurora.
Here’s their explanation. Aurora is one of many U.S. cities that has implemented “increasing block rates” – low rates for basic water use, then rising rates per unit water used if you’re more profligate. What they found the smart meters do is help users realize when they’re over or under the block. If they’re a bit over, the smart meter helps them conserve to drop down to the lower priced block. This saves water. But for users who aren’t close to the level where their use would bump them into the higher block, the additional information seems to make them comfortable using more water: “Hey, the longer shower isn’t a big deal, because it’s not enough to bump me up into the higher block.”
After the device is installed, households become aware of where, within the price structure, they are consuming. On net, the average consumer increases water consumption but those that decrease, decrease enough to jump under block boundaries.
The paper has lots of caveats, so this shouldn’t be the last word on smart meters in the water world. But I love results that run counter to my beliefs and expectations.