Why big data is key to maximizing water conservation's impact

In places like Arizona, California, Colorado, Florida, Georgia and Texas, water supplies are declining even while cities continue to grow. For the first time, parts of the United States face a real risk of running out of water.

What if it were possible to head off catastrophic water shortages through strategies that resulted in customers reducing their water use? With water shortages growing acute in some of the nation’s fastest growing regions, water planners and political leaders are calling for the urgent development and deployment of water conservation solutions.

But how can planners verify that a particular product actually produces water use reductions? Surprisingly, in most instances they can’t.

Imagine if doctors had to decide whether to prescribe a medicine and there was no such thing as the FDA or clinical trials. How would doctors know which medicines actually performed as claimed? That is the environment, however, in which water planners currently must evaluate products that claim to produce water conservation impacts.

With the growth of big data and smart metering, it is now possible to apply data-driven measurement and verification to verify the water conservation impacts of the numerous products appearing on the market.

Water conservation products actually fall into three categories, however:

(1) Efficient Operation;

(2) Set and Forget, and

(3) Intentional Engagement.

Determining which category a possible solution fits within is a critical first step. That’s because products in each of these categories employs distinct processes for achieving water use reductions. And that means the metrics and the measurement and verification processes that one should apply to products in one category frequently won’t fit well for evaluating a product in another category.

For planners seeking to verify the water conservation claims of various water conservation products, here are key factors to consider for each of these three product categories. By employing the correct metrics and measurement and verification processes, water planners can ensure that water conservation products actually produce water use savings.

Efficient operation products

Efficient operation solutions are primarily products that require less energy or water to do a job than the product customers are currently using.

Examples:

• Low-flow toilets,
• front-loading clothes washers
• native landscaping.

Is behavior change required to achieve water use reductions?

No. Efficient operation solutions do not require ongoing behavior change to achieve savings. Instead, from a customer’s perspective, they typically work the same as the product the customer had before. For example, a customer who installs low-flow toilets and flushes the toilet exactly as much as before will still reduce water use from flushing by as much as 80 percent.

Requirements – measurement and verification and data:

Because efficient operations products largely do not rely on behavior change to achieve water use reductions, the conservation impacts of these products can frequently be verified through lab testing. (I.e., field testing is not required.) However, determining actual water savings requires solid models of how often a typical end use actually is used by customers and how these use levels are impacted by the number of residents and ages of these residents.

For instance, determining that a front-loading clothes washer saves 20 gallons of water each time it is used compared to an older top-loading clothes washer still won’t answer the question of how much water a customer will save from buying a front-loading washer. The answer to that question also requires knowing how often that customer uses a washing machine.

Set-and-Forget products

Set-and-Forget solutions achieve water savings through use of conservation-focused default settings or by equipping the product with technology that optimizes the product’s settings and operation run times without need of customer engagement. The magic in these product typically resides in software or in the cloud rather than in hardware. These types of products are based on the behavioral economics principle that people are overwhelmingly prone to not changing the default settings of their products.

Examples:

• Nest learning thermostat (uses a mix of on-board motion sensors and software to automatically change air conditioning temperature settings when people are not home)
• Smart sprinkler system controllers that by default set efficient run times for zones and automatically cancel a scheduled water cycle when it has rained recently

Is behavior change required to achieve water use reductions?

Little to no behavior change is required. At most, the customer needs to engage with the product at set up. After the product is set up, the customer is free to alter settings, but if s/he does not alter the settings, the product’s technology will automatically set the product to operate in a pattern that produces reduced water use.

Requirements – measurement and verification and data:

Verifying water use reductions for this class of products usually requires field testing in actual homes and businesses.

To understand why, consider this example from an air conditioning system. To reduce AC energy use, one could install an air conditioning system with a high SEER rating (an Efficient Operation approach). Under that approach, no behavior change would be required; instead, the new high-efficiency system would use less energy to produce the same level of cooling. Alternatively, one could keep the current AC compressor but install a smart thermostat (a Set-and-Forget approach). The AC compressor would use the same amount of energy when it ran but the thermostat would produce energy savings by running the compressor less often (such as when residents were away from home).

To verify a Set-and-Forget system’s effectiveness, it is necessary for homes where field testing takes place to be equipped with high resolution water use measurement equipment that ideally measure water use at least once a minute.

Intentional Engagement products

Intentional Engagement products achieve water use reductions by motivating customers to change behavior based on information and/or recommendations provided by the program.

Examples:

• Fitness trackers and apps (e.g., FitBit, running and dieting apps)
• Consumer engagement platforms/software
• Tiered water rates

Is behavior change required to achieve water use reductions?

Yes. A defining feature of these products is that they do not have control functions but instead rely on information alone to motivate customer behavior change.

Requirements – measurement and verification and data:

Verifying water use reductions from this category of products can only be assessed through field testing. As with Set-and-Forget systems, homes where testing takes place should be equipped with high resolution water use measurement equipment that ideally measure water use at least once a minute.

At that resolution, changes in water use can be isolated down to the appliance level. This level of resolution also makes it possible to determine, for example, whether a customer actually did not run the sprinkler system on her/his normal water day the day after receiving a recommendation from an app to turn off the sprinkler system.

Brewster McCracken is President and CEO of Pecan Street Inc., a nonprofit research institute based at The University of Texas at Austin. Previously, he served two-terms on the Austin City Council. Through this elected position, he served as a board member of Austin Energy and Austin Water, and founded and chaired the city council’s Emerging Technologies Committee. He is an honors graduate of Princeton University and The University of Texas School of Law, and holds a master’s degree in public affairs from UT’s LBJ School of Public Affairs. For more information, follow Brewster on Twitter @bmccracken and @PecanStreetInc, or visit www.PecanStreet.org.  

The views expressed by contributors to the Cynthia and George Mitchell Foundation's blogging initiative, "Achieving a Sustainable Texas," are those of the authors and do not necessarily represent the views of the foundation.  

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