Energy meters have long existed as an electromechanical unit requiring a manual operator to gather meter readings.

The process had shortcomings including time delays and human errors that waterfall down to inaccurate billing and payment collections. Furthermore, present-day challenges in power management are best suited by a product that can identify usage profiles and peak demand through seemingly instantaneous measurements and two-way communications.

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Advanced metering infrastructure (AMI) showcases its efficiency and capabilities as it answers these shortcomings while it encompasses an increasing portion of developing countries' metering schemes.

AMI serves as a local link in a utility grid. Each unit has a unique address coupled to a user profile and its consumption curve. The iterative measurements send data to a local contractor who develops a contract with the client specifying purchase and delivery options.

Through use of AMI many pitfalls of traditional electromechanical operations are overcome including power theft, missed meter readings, and human measurement errors. Abilities to implement pre-paid metering schemes with greater accuracy as well as control transmission remotely are also introduced, which helps stabilize the grid and prevent power theft.

The three major components of AMI that supports its added functionality are the power source, microcontroller, and interface, although recent efforts to incorporate more functionality in AMI may jeopardize data security as multiple concurrent users attempt to harness data and control functions. In an effort to heighten security functions, the Horizon 2020 project Nobel Grid introduced the idea of an unbundled smart meter (USM).

The USM concept componentizes AMI. The fixed-functionality of the base module referred to as a smart metrology meter (SMM) is used to heighten security and protect privacy-sensitive data. A smart meter eXtension (SMX) adds additional functionality and flexibility to support concurrent users and the future evolution of the smart grid.

IEEE Smart Grid’s recent publication “Unbundled Smart Meter Design Solutions and Lessons Learned” found that the 2017 project aims to test two variants of the USM concept. The first test case uses existing smart meters as the SMM alongside separate SMX modules that use public IP networks and concurrent connections.

The second test case of the 2017 Nobel Grid USM project incorporates what is referred to as SLAM (smart low cost advanced meter). SLAM offers advanced functionalities in the SMM while the SMX acts as a meter gateway.

Initial shortcoming of using existing SMM is that existing infrastructure encompasses a multitude of protocols, some non-standard. This may present data security issues. The alternative, SLAM, incorporates a database-centric architecture with enhanced role-based access control (RBAC) in order to control access to privacy-sensitive data. The SLAM strategy only allows users to communicate with SMX through a virtual private network further securing data while adding functionality needed to address the evolution of the smart grid.

The unbundled architecture may be an attractive design concept that is gaining appeal. The expectation is that consumers will have the ability to interact with smart appliances and energy usage data through USM. To make those dreams reality, third-generation smart meters and expansion of USM into future projects unfold as engineers work to ensure the security of critical energy infrastructure.