Advanced Metering Infrastructure Will Have Unexpected Impacts on Utilities
- Written by Robert Heile
As both the Smart Grid and smart metering roll out across the country, the arrival of new technology innovations inevitably will change the expectations that both utilities and customers have of advanced metering.
Standards will play a key role in determining the attributes and operating characteristics of advanced metering infrastructure. In fact, experts from diverse disciplines collaborating in standards development will be among the first to forecast how the evolution of the Smart Grid will affect metering expectations. The standards-making process also offers the best means of accommodating innovation, because as standards are revised, the dissemination of the new functionality is more or less automatic.
In the meantime, utilities have a number of factors to consider as they go about constructing a secure communications infrastructure for advanced metering. As in all engineering projects, the goal is to be cost-effective today and yet flexible enough to accommodate future Smart Grid benefits such as improved service reliability, more automated distribution and efficient operations, consumer usage options (such as automated management of appliances), and time-of-use pricing, to name but a few.
It is useful to recognize that Advanced Metering Infrastructure (AMI) is both inward facing—collection and distribution of data inside a home or enterprise—and outward facing—the collection and distribution of data by the utility to and from the meter.
While it’s possible to imagine a single optimal solution serving all, it is more realistic to proceed on the assumption that many communications options will be developed to enable home area networks, all capable of running ZigBee Smart Energy. Inside the home, the network will enable families to manage electric usage and take advantage of time-of-use pricing. Many devices can be home-network connected, including smart thermostats, which are likely to stay in the building, but also appliances that could move with the family to another utility’s service area. The mobility of appliances reveals the need for standard communications interfaces across multi-vendor home networking devices and advanced metering solutions.
IEEE 802.15.4g is being developed to satisfy the outward facing portion of the network. It describes the utility-to-meter communications link of the ZigBee Smart Energy (ZSE) Profile, which is the leading standard for smart metering and the home area network. ZSE provides the capability needed for the utility to interact in a defined way, through the meter, with the consumer and the devices in the home for status monitoring and load control—which will be especially needed in the emerging era of electric vehicles and plug-in hybrids. ZigBee Smart Energy devices can be used in any service area and can be supplied by multiple vendors. The system gives consumers the means to collect information about their energy usage regardless of supplier, affording them opportunities to manage their usage with or without a smart meter.
In order to create a viable advanced metering communications infrastructure and relevant standards, it is important to understand the spectrum of applications it will serve.
While the Internet will play a valuable role in home energy management, its use will be primarily to provide consumers with third-party portals to help them monitor and manage their energy environment and to give them remote access to their home network. It is unlikely the utilities will want to use the Internet for any essential services related to customer billing or service disconnect switches since these connections rely on customer-owned routers and other equipment that may not always be available when needed and may not be configured with adequate security measures to protect the integrity of the grid. In the long term, it seems likely that the integrity of the advanced metering communications link will become a critical business issue for utilities.
A good example of how all this is coming together can be seen in Southern California Edison’s implementation its SmartConnect metering system. SCE’s goal is to enable customers to monitor usage and costs. By communicating with smart appliances in the home over a local network, SCE plans to monitor system demands and let customers program those appliances to respond automatically so they can benefit from flexible pricing models. SCE residential customers can view their usage data hourly and business customers in 15-minute increments.
SCE started deploying smart meters in 2009 and presently has more than 1 million installed with the expectation of equipping about 5 million residential and small-business customers by the end of 2012. Its SmartConnect metering system rollout will eventually cover the utility’s whole 50,000-square-mile service area.
The utility has constructed a multi-tiered infrastructure that consists of: A cellular-based wide-area network, with two-way narrowband 900 MHz radio-frequency wireless communications to the meters, and, between meter and home, ZigBee Smart Energy standards-based home-area communications at 2.4 GHz RF using IEEE 802.15.4. Although customers view usage over the Web, the basic data is collected and delivered to the utility over its wide area network. That ensures the accuracy, security, privacy and integrity of the data, and yet makes the results easily available to the consumer, anywhere.
More than 100 utilities have turned to SCE for best practices on smart meters, synchrophasor measurement, electric-vehicle and renewables integration, energy storage and other Smart Grid technologies.
To accommodate present and future applications, utilities need to forecast utility-to-meter communications requirements. Among the basic performance parameters are bandwidth, response times and latency requirements. Utilities may also wish to support remote testing, maintenance, monitoring, and upgrade services from the utility to smart meters. Although advanced metering will generate significantly more information at more frequent intervals than utilities have collected before, the number of bits per second is still small compared to streaming audio or video, as utility communications are primarily with sensors and controllers. So unless a utility plans to offer Internet-access or other data-intensive services, broadband is probably not necessary.
Smart meters represent one of the most visible encounters utilities will have with the demand-responsive Smart Grid and its two-way communications and control. This largely unknown territory demands new policies and regulations, consumer education, and technologies, processes, and skill sets, as well as a set of consensus-based standards optimized to support it. This is the mission of groups like IEEE P2030, IEEE 802 and the ZigBee Alliance.