The poles and wires of America's electric grid have changed little from their 19^th century origins, even as consumer demand for reliable electricity skyrockets in the 21^st century. To meet rising demand and consumer expectations for reliability, CenterPoint Energy Houston Electric is bringing its electric grid into the digital age by deploying more than 2 million smart meters over the next two years and beginning to build an intelligent, self-healing grid. More than one year and 400,000 meters into the deployment, this transmission and distribution utility has already learned valuable lessons to share with the industry.

Opportunities for Competitive Electric Market

In its deregulated Texas electric market, CenterPoint Energy delivers electricity to more than 2 million meters in Houston, Texas, on behalf of nearly 100 competitive retail electric providers. Advanced metering systems (AMS), now being deployed by several T&D utilities across the state, will help foster retail competition and deliver many potential benefits to consumers, such as new retail products and services, which could include the following:

• Prepaid service
• Time-of-use rates
• Off-peak usage rebates
• Energy analysis and cost-comparison tools
• Remote control of appliances and thermostats in a home area network (HAN).

For CenterPoint Energy, AMS is an integral part of a comprehensive project to build an intelligent grid with power line sensors, remote switches and other distribution automation equipment to improve electric reliability and power restoration.

Smart Grid Journey

Though CenterPoint Energy is making its system smarter, it is far from dumb now. For more than 20 years, the utility has used limited distribution automation equipment such as remote switches, solid-state relays, supervisory control and data acquisition (SCADA) and remote capacitor controls.

From 2005 to 2007, the utility conducted research and development of smart grid technology and executed a pilot deployment of 10,000 smart electric meters in Houston. One product of the research and development effort, which has reaped ongoing benefits, is the CenterPoint Energy Technology Center, where the utility performs some key tasks:

• Tests the interactive performance characteristics of diverse smart grid components

• Evaluates the performance and security of HAN-controlled devices and appliances

• Educates consumers, public officials, the media, vendors and industry peers about smart grid technology, having conducted more than 500 escorted tours of the Technology Center to date.

In December 2008, the utility received approval from the Texas Public Utility Commission (PUCT) to deploy more than 2 million smart electric meters, beginning in March 2009. In October 2009, CenterPoint Energy was one of six utilities awarded a US$200 million smart grid investment grant by the U.S. Department of Energy (DOE), $150 million of which will accelerate completion of the AMS deployment, moving up the date from 2014 to 2012.

CenterPoint Energy will match the remaining $50 million to begin building an intelligent grid serving more than 500,000 customers in central Houston by 2013, which the utility hopes eventually to extend throughout its 5000-sq mile (12,950-sq km) electric service territory in greater Houston.

More Than a Meter

CenterPoint Energy's smart meter of choice is Itron's OpenWay digital meter with an open-protocol, standards-based architecture and a ZigBee radio chip, capable of two-way communications and a host of smart functionality:

• Automated meter reading and on-demand reads

• Remote connect and disconnect

• Outage and tampering detection

• Support of HAN devices, load control and demand response

• Mutlichannel metering for distributed generation.

The meters collect 15-minute interval data, transported from the meters through a radio-frequency mesh network to cell relays on distribution poles, featuring GE radios, to radio tower take-out points at substations (with failover to cellular GSM [Global System for Mobile communication]), and then by microwave or fiber-optic cable to the utility's data center. There, eMeter's Energy IP meter data management system processes the 96 daily reads per meter and electronically executes all types of customer-requested service orders remotely.

With IBM, a consortium of Texas T&D utilities, including CenterPoint Energy, has designed, developed and deployed the Smart Meter Texas common portal and data repository to serve as a single repository of usage data for customers with smart meters in areas served by these utilities. The portal gives consumers and their retail providers access to historical 15-minute interval data to show in a graphical format how much electricity has been used and when it was used without having to wait for a monthly bill. Retail providers — and soon consumers — may provision and de-provision HAN devices through the portal, through which retailers will be able to send price signals and load-control commands to their designated customer base. Consumers also will be able to receive outage notifications through the portal and authorize aggregators, energy analysts or other third parties to access their usage data.