How smart water meters save energy


By Machiel Joosse and Gerrit Rentier, DELTA N.V.

With the growing awareness worldwide of the environmental impact of energy use and water use, and with the economic belt tightening, many municipalities are looking to promote energy efficiency and cost efficiency. From that perspective we as a municipal utility have developed an innovative concept that uses data from smart water meters to promote energy awareness and energy efficient behavior with customers. The approach uses the Dutch architecture for smart meters by adding smart water meter data to existing smart meter data for gas and electricity, and delivers that data to the home continuously.

Strategy and vision

DELTA N.V. is a multi-utility company locally owned by shareholders, the Province of Zeeland and all local municipalities. DELTA owns power plants, waste treatment facilities and a local grid operator. Also we provide water, cable and multi-media services locally, and we provide electricity, gas and metering services nationally. DELTA adds value to stakeholders through synergy, embodied in the multi-utility strategy.

At DELTA N.V. we believe that water, energy and nature are valuable resources that we as a society should approach with respect as well as in conjunction. As a municipal multi-utility it is in the nature of DELTA to focus on added stakeholder value including sustainability, in a multi-utility approach. We are looking for cost efficiency, innovation, consumer empowerment and energy efficiency through integrated offerings. This synergetic approach is also reflected in our corporate vision regarding smart meters.

Smart meters – electricity, gas and water
In the same way that smart meters are a key component of the electrical smart grid, similar technology can be applied to other utilities like gas and water. For electricity, gas and water metering, more accurate hourly interval reads can provide great savings and an enhanced customer experience.

Looking for innovation to effectively promote energy efficiency, we realized the relevance of the fact that continuous information in the home has significantly more effect on energy efficiency behavior than monthly home energy reports or bills. The Empower Demand study reports that “on average an in-home display is 50% more effective than an informative bill at reducing overall electricity consumption” (“Empower Demand” study 2011, VaasaETT/ESMIG).

Furthermore we learned* that more than half of the water that is used in a Dutch household is heated. This means that water use has a profound relation with energy use in the home, and holds valuable information on energy efficiency and on the energy budget of a family.

Earlier smart meter pilots at DELTA already taught us in 2007 that graphs based on interval data for water use enhance the customer’s understanding of energy use. For instance, peaks in water use that coincide with peaks in gas use are a clear indicator of activity in the bathroom (showers or baths). Likewise, peaks in water use that coincide with peaks in electricity indicate the running of dish or clothes washers. In those pilots, we presented customers every day with conservation encouraging usage and bill estimation via a web portal with interval data from the day before.

At the start of 2013 we decided to join these two insights in a new value proposition, presenting the data in the home on an hourly basis through an energy management system, graphically displaying it on smart phones, tablets and computers. We put the idea to the test by rolling it out as a proof-of-concept amongst colleagues.

Lessons learned and next steps
The Dutch smart meter architecture (DSMR) positions the smart electricity meter as a data hub within the home, because it is always connected to the mains. Moreover, it also allows for up to four local slave meters. Since the Netherlands has a mandated national rollout for electricity and gas, one of the local slave meters will almost always be a smart gas meter. Locally, consumers can read out data through the customer interface (P1-port, a simple RJ-11 connector).

Dutch arc

In our proof-of-concept we have learned that for installation, commissioning and reading out both locally (in the home/home area network) and remotely (utility IT system/wide area network), it is very straightforward to copy the data structures and procedures for gas to that of water. Of course, the same would go for other local slave meters, e.g. for district heating, electric car charging or solar panels.

However, a challenge is to make this concept competitive with smart home products. Smart home products make local data available to the customer on a more frequent basis, though that data isn’t encrypted and it isn’t suitable for billing. We are currently looking into the feasibility of improving the performance of the local interface (P2-port, the connection between slave meters and the electricity meter).

Another challenge is to integrate the asset management for the water meters with the asset management for the energy meters. This is because in the Netherlands, energy meters are owned by grid operators, but water meters are owned by water companies.

Stakeholders and social value
The biggest challenge we found is stakeholder alignment. It is evident that a combined smart meter rollout for water, gas, and electric metering allows for a better financial and social business case. The costs for rollout are lower per service if one appointment and one truck roll take care of three services at once. And as we hope to have argued in this article, the customer value increases by more than the sum of those three, through synergy effects that give the customer extra understanding.

However, in many regions and countries, there is no central stakeholder for all three services. Therefore, ownership of the business case is not with a single company or even a single government body.

In France, for instance, three separate utility companies will roll out smart metering for each service separately. In the U.K. and Ireland, we find that smart meters for electricity and gas are rolled out together nationally, and smart water meters are rolled out across large regions – but they are not rolled out together.

But many municipal utility companies exist that indeed do offer all three services and more (e.g. district heating) to citizens living in the municipality, particularly in Germany (so-called “stadtwerke”, of which there are over 900), Scandinavia and the U.S.A. (over 2,000). For those municipalities in particular, it could be well worthwhile to consider the value in multi-utility smart metering, as described in this article.

A local multi-utility smart meter rollout for electricity, gas, district heating and water could save valuable resources as well as reduce public costs. This would help alleviate the public budget for the area or city. The investment could generate predictable returns associated with resource conservation upgrades like this one, in addition to improved asset management of distribution infrastructure and improved customer processes. Further value for the region could be obtained through using a municipality-wide network for other municipal functions, for an even more complete “smart city” concept.


* VEWIN report “Dutch drinking water statistics”

Video of customer feedback example: “Direct in-home feedback with Dutch Multi-Utility Smart Metering”

About the authors

Machiel Joosse is responsible for smart metering technology at DELTA Netwerkgroep since 2008. He is active in national technically oriented working groups, often within Netbeheer Nederland, the Dutch association for DSOs.

Gerrit Rentier works as an analyst and project leader for DELTA N.V. and has been actively involved with smart metering since 2007. He also participates in national regulatory discussions concerning smart meters, energy efficiency, demand response and consumer rights.

Delta N.V.