Efficiency at the Edge: How ComEd’s Voltage Optimization is Redefining Grid Management

In an era where the utility sector is under immense pressure to balance the transition to clean energy with the growing demand for affordability, ComEd has emerged as a leader in grid modernization. The Illinois-based utility recently announced a milestone achievement in its Voltage Optimization (VO) program: the delivery of approximately 100,000 megawatt-hours (MWh) of energy savings to its customers. By leveraging advanced automation and intelligent data analytics, ComEd has demonstrated that the path to a more sustainable grid is not just about adding new generation, but about wringing maximum efficiency out of existing infrastructure.

This achievement, which has resulted in over 65 gigawatt-hours (GWh) of verified energy savings, represents a paradigm shift in how utilities manage the distribution of power. Rather than relying on traditional, resource-heavy maintenance models, ComEd has successfully implemented a system that lowers the delivered voltage to the lower boundary of the ANSI C84.1 standard. The result is a seamless, invisible optimization that allows customer appliances to run more efficiently without any behavioral changes required by the end-user.

The Technical Mechanics of Voltage Optimization

At the heart of the VO initiative is a sophisticated, automated control system. Traditionally, utility grids were designed to deliver voltage at the higher end of acceptable ranges to ensure that even the most remote customer received adequate power. However, modern equipment is often designed to operate within a broader, more efficient range.

ComEd’s program utilizes dynamic control over substation load tap changers (LTCs) and line regulators. By precisely managing these assets, the utility can keep voltage profiles within the lower, more efficient thresholds of the ANSI standard. This reduction—typically resulting in a 2% to 3% decrease in energy consumption—is achieved by optimizing the power flow across the distribution system.

This is not merely a "set it and forget it" mechanism. It requires a constant, high-speed feedback loop between the grid edge and the centralized command center. By integrating advanced automation, ComEd has turned its distribution network into a responsive, intelligent machine that adapts to real-time fluctuations in demand.

Chronology: From Pilot Study to Utility-Scale Infrastructure

The trajectory of ComEd’s VO program is a case study in strategic scaling. What began several years ago as a targeted energy efficiency pilot has evolved into a comprehensive, enterprise-wide deployment.

• 2018–2020: The Foundation Phase. ComEd initiated its investment in VO, recognizing the potential for significant efficiency gains. During this period, the utility focused on the foundational infrastructure required to support automated voltage control, including the deployment of advanced metering infrastructure (AMI) and the initial digital upgrades to substations.
• 2021–2023: Systems Integration. As the program moved beyond the pilot stage, the challenge shifted to integration. This period saw the synchronization of transmission and distribution (T&D) systems, requiring a massive overhaul of existing network models and GIS mapping to ensure that automated controls were acting on accurate, real-time data.
• 2024–2025: Massive Scaling. With the success of early deployments, ComEd accelerated the program. In 2025 alone, the company upgraded 16 additional substations, bringing the total number of participating facilities to 292. Of these, 245 are currently operating in full-time, continuous VO mode.
• Present Day: With over $550 million invested since 2018, the program has matured into a cornerstone of ComEd’s operational strategy, driving both environmental and economic benefits.

Data-Driven Maintenance: The "Intelligent PM" Strategy

One of the most profound impacts of the VO program is the transition from calendar-based maintenance to condition-based proactive maintenance, or what ComEd calls "Intelligent PM."

Jason Pozen, manager of distribution automation at ComEd, highlights the transformation of the utility’s capacitor banks—critical assets for managing voltage on 12 kV and below systems. Historically, these units operated in isolation, lacking any data communication capabilities. "They relied on local settings, and we had to send out trucks for manual preventive maintenance inspections on all of them," Pozen noted.

With the VO rollout, ComEd equipped these assets with two-way, remote communications. By leveraging real-time SCADA (Supervisory Control and Data Acquisition) telemetry, the team developed custom algorithms that continuously analyze voltage, current, and reactive power.

This technological leap allows the utility to identify subtle anomalies—such as blown fuses, failed switches, or controller damage—before they escalate into system-wide failures. Instead of the costly and inefficient practice of manually inspecting 8,000 capacitor banks annually, ComEd now dispatches crews only to the 500 or so units that exhibit verified performance issues. This optimization has had a measurable impact on the utility’s SAIDI (System Average Interruption Duration Index) and SAIFI (System Average Interruption Frequency Index) metrics, directly correlating infrastructure health with improved service reliability.

Official Perspectives and Cross-Functional Collaboration

The success of such a complex, utility-scale deployment cannot be attributed to a single department. It represents a massive cultural and operational pivot. David Perez, executive vice president and chief operating officer at ComEd, has championed the VO program as a critical intersection of grid modernization and affordability.

The execution of the VO program relies on a "highly collaborative, enterprise-wide machine." According to Pozen, the project requires the seamless integration of several disparate teams:

• Transmission and Substation Teams: Responsible for the physical upgrades to grid hardware.
• Distribution Engineering: Tasked with the complex feeder-line work in the field.
• AMI Team: Instrumental in selecting and retrieving high-resolution data from "bellwether" meters located at the grid edge.
• Energy Efficiency Group: Vital for the verification and validation of the MWh savings, ensuring the program meets regulatory and internal performance standards.
• Project Management Office (PMO): The centralized engine that ensures capital projects remain on schedule and within budget.

Implications for the Future of the Grid

ComEd’s VO deployment offers a blueprint for utilities across the globe. As the industry faces the dual challenge of aging infrastructure and the integration of volatile, intermittent renewable energy sources, the ability to control voltage with high precision is becoming a prerequisite for grid stability.

The Challenge of Holistic Modeling

One of the most critical lessons identified by the ComEd team is that distribution cannot be managed in a vacuum. As Pozen emphasized, "You have to conduct comprehensive, end-to-end studies." Scaling this technology successfully requires highly accurate GIS network maps and a deep, proactive understanding of how sustained lower-voltage profiles interact with the broader transmission system. For other utilities looking to replicate this success, the technical hurdle is not just the equipment itself, but the underlying data model that links the substation to the grid edge.

Affordability as an Operational Mandate

In an economic climate where utility bills are a significant concern for households, ComEd’s VO program provides a tangible mechanism for cost reduction. By eliminating energy waste, the program lowers the total energy requirement of the grid. These are not theoretical savings; they are verified, annualized reductions that help dampen the impact of rising energy costs.

The Path Forward

The success of ComEd’s VO initiative underscores a growing trend in the utility sector: the shift from "passive" grid management to "active" grid orchestration. By investing in sensors, communications, and advanced algorithms, utilities are moving away from reactive, manual processes toward a future where the grid is self-correcting and inherently efficient.

As ComEd continues to refine its VO program, the focus will likely remain on integrating more granular data and expanding the scope of its automated controls. The $550 million investment has already paid dividends in terms of operational efficiency and, more importantly, in establishing a foundation for future innovations. As the energy landscape continues to evolve, the ability to squeeze efficiency out of existing assets will be the hallmark of the most successful utilities—a testament to the power of engineering, collaboration, and a relentless focus on the customer.