By Maureen Trumble

In fact, the company’s Advanced Metering Infrastructure (AMI) programme is a critical step in creating the smart grid’s foundation. Earlier this year, an investigation was started on AMI while formulating the Balanced Energy Initiative, a comprehensive plan to meet the energy needs of Consumers Energy’s 1.8 million electric customers for the next 20 years. AMI and the Balanced Energy Initiative are also aligned with Michigan’s 21st Century Energy Plan, issued in January by the then-chairman of the Michigan Public Service Commission.

EVALUATING AMI BENEFITS
A well designed AMI initiative offers a unique opportunity to provide tangible benefits for Consumers Energy’s customers. By providing energy usage information, load management capabilities and demand response programmes, customers are expected to become more efficient in managing their energy usage. By sending appropriate pricing signals, the AMI initiative will provide an opportunity for residential customers to reduce their power usage during high cost, critical peak demand periods.

To promote AMI’s load-management capabilities, customers will be able to volunteer to take part in an air conditioning load cycling programme, starting in 2010. This programme will allow the utility to cycle their air conditioners on and off, reducing usage on peak demand days and shifting load to cooler evening hours when energy costs are lower.

Functionality

Functionality of AMI

For demand response programmes, customers will have the opportunity to use programmable, communicating thermostats, which may be adjusted remotely for load reduction during peak demand periods. AMI’s two-way communications system will connect thermostats to electric smart meters, which in turn will send data to Consumers Energy’s computer systems. With AMI’s advanced technology, all electric meters will be replaced with smart meters and communications modules will be added to existing gas meters.

Combined with other AMI technology infrastructure, Consumers Energy will be able to provide automated hourly meter reads, remote meter connects and disconnects, demand response, load control, customer price signals, outage detection, energy theft deterrence/detection and power quality reporting.

Customer information will be readily available online for high bill questions and real time service turn-ons and turn-offs. In addition, AMI will offer customers a variety of billing options, such as summary billing and custom due dates for bills.

Putting an AMI application in place will provide a significant competitive advantage in the fast developing world of interactive energy services. As a result, this AMI programme will improve operations, reduce costs, enhance customer experiences, meet performance standards and enable smart grid capabilities.

Consumers Energy’s AMI approach follows a middle path between adopting leading technology immediately and waiting for peers to move forward into this new customer-interactive world. Risks associated with this evolving technology will be mitigated by participating in industry forums and the AMI@SAP Lighthouse Council, a group of leading utilities developing AMI software requirements.

Operational savings will result from enhanced processes, while the ability to detect and localise power outages without customer notifications will bring faster restoration times and better customer service. These AMI benefits will set the stage for a smart grid to enhance the reliability of Michigan’s energy systems and encourage optimisation of grid assets.

PROPOSING AMI ARCHITECTURE DESIGN
However, these AMI benefits will not be realised without the right architecture design and infrastructure components. The appropriate architecture is being designed to ensure that infrastructure integrates with existing technology, such as supervisory control and data acquisition (SCADA), and automated generation control (AGC) systems and future field technology, including distribution automation.

AMI’s technology will be running initially in a parallel path with SCADA. Both AMI and SCADA will provide remote data acquisition and control capabilities. While SCADA interfaces with generating plants and substations, AMI will talk to meters, plug-in hybrid cars and distributed generation.

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Consumers Energy's IT strategy

The proposed AMI architecture emphasises security by establishing a clean interface between the secure technical solution and the business/commercial solution that will meet the North American Electric Reliability Council Critical Infrastructure Protection (NERC CIP) security standards. Meanwhile, the meter and grid historian will support the data requirements for all field technology – primarily AMI, SCADA and distribution automation.

In other words, the meter and grid historian will act as a thin meter data management system (MDMS), or what we call a meter data unification system (MDUS), to store operating data collected from the field. Ultimately, the MDUS will be an interface between business systems and field architecture. The MDUS will use a standards-based services oriented architecture to minimise custom interfaces to the existing and future business systems. AMI extensions will be incorporated into the upcoming conversion to the SAP application, and these extensions will eliminate the need to develop new stand-alone systems for AMI. In early 2008, Consumers Energy will launch a comprehensive enterprise application software suite from SAP.

This software will replace more than 100 legacy systems. It will allow streamlining, automation and elimination of manual work and improvement in the flow of work and information companywide. Among many other systems, the AMI architecture will integrate with outage management systems (OMS) and distributed resource availability and control systems (DRAACS). With OMS, it will be possible to handle a higher volume of outage notification messages and use outage restoration messages to eliminate customer impact and additional costs associated with a nested outage.

DRACCS also will be developed to simulate the capabilities of many individual customers to reduce or shed load along with using customer-owned generation. That load reduction and customer-owned generation will be aggregated to a value that’s useful in the control centres.

EXAMINING AND IMPLEMENTING AMI INFRASTRUCTURE
To provide the framework for AMI’s architecture, different types of infrastructure components for the initiative will be examined. The infrastructure components must be flexible and secure in their design while simultaneously using standardised interfaces. These components will be implemented from the back end (i.e. company side) to the front end (i.e. customer side).

As mentioned previously, Consumers Energy’s infrastructure will be comprised of SAP software integrated with AMI extensions and an MDUS to store and analyse meter data. Once the MDUS is implemented, it will link to head-end devices. These devices will oversee the transmission of data from the smart meters and monitor end-to-end connections. Head-end devices, which must adhere to common interoperable standards, will ensure smart meters are communicating properly.

For the next infrastructure components, back-haul communications networks and concentrators will transport meter data to head-end devices. In turn, concentrators will provide a logical interface between the communications network to the data centre and local meters. This will allow concentrators to capture meter data flowing through wired or wireless networks.

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AMI infrastructure

Ultimately, data will come from the implementation of electric smart meters and communications modules for existing gas meters. Much emphasis will be placed on choosing a communications module that allows software component upgrades automatically through the two-way communications network. The programme team is investigating whether the communications links should include wired or wireless connections.

Home area networks (HANs) will link smart meters to various devices, ranging from thermostats to air conditioners to appliances, in customer homes. By using HAN-based devices, customers will be able to participate in air conditioning load cycling, demand response and energy efficiency programmes. Open communication standards for HANs will assure multiple appliances and other devices can work interchangeably within the AMI infrastructure.

TAKING THE NEXT AMI STEPS
For the next steps, the design phase will be entered into to refine the business case and conduct limited product testing later this year and into 2008. Field testing of meters, enduser devices, communication networks and security features will begin in 2008 and continue through early 2010. Two early deployment programmes will be conducted in 2008 and 2009. The plan calls for full meter replacement of 1.8 million electric meters and installation of communications modules to 1.7 million existing gas meters to occur between 2010 and 2014.

Lastly, the AMI initiative, along with those at other utilities, will help lay the foundation for smart grid applications and revolutionise the industry. Future energy systems will improve reliability and security while emphasising environmental stewardship. As demand for energy in Michigan increases, additional energy generation will be required and systems will need to become smarter and more flexible. While the smart grid is in its infancy, Consumers Energy strongly encourages interoperable, compatible AMI architecture designs and infrastructure components to help the smart grid grow and flourish.