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Hydropower continues to be one of the most reliable and flexible clean‑energy resources in the United States. However, many generating units are relying on aging excitation hardware and control systems that limit visibility, slow troubleshooting, and increase operational risk. As utilities face higher peak-demand periods and more extreme weather, modernizing these systems is essential for improving efficiency and reliability, reducing costs, and extending asset life.

Salt River Project (SRP), which provides hydropower and water delivery to the Phoenix area, recently completed a comprehensive modernization across four hydroelectric dams. Facing aging excitation systems with limited OEM support available, SRP partnered with Emerson to standardize plant controls and excitation systems on the Ovation™ Automation Platform. This unified architecture has strengthened unit performance, improved operational insight, and reduced lifecycle costs.

By integrating all excitation functions—control, protection, diagnostics, and oscillography—directly into the same platform used for plant automation, SRP created a fleetwide controls framework that ensures consistent visibility and operational behavior across all dams. This alignment has been particularly valuable for remote and pumped storage units, where visibility into excitation performance is crucial for maintaining reliable operation under rapidly changing grid conditions.

Operational Benefits at a Glance

• ~30% reduction in O&M costs through platform standardization and reduced spare‑parts inventory.
• 50% faster troubleshooting enabled by pre‑triggered high‑speed oscillography and integrated diagnostics.
• Elimination of 15–20 minute manual resets that previously slowed startup, improving operational flexibility.
• Supports SRP’s long-standing 90+% performance rating by strengthening unit reliability and ensuring fast‑response capability during peak demand.
• Improves operator efficiency through a more responsive exciter HMI with unified single-line diagrams and alarm lists that accelerate fault localization.
• Safer, more efficient pumped storage operation through tailored excitation logic.
• Stronger cybersecurity posture with standardized network architecture and unified patch management.

How SRP Achieved these Results

SRP selected Emerson’s Ovation automation platform solution to support its fleetwide goals, including improving pumped storage reliability, reducing troubleshooting time, and enhancing startup efficiency. Modern excitation capabilities, such as redundant processors, dynamic bridge balancing, bumpless transfer, high‑speed event recording, and integrated Power System Stabilizer functions, now operate within the same environment as plant controls. Operators view alarms, diagnostics, historian data, and unit behavior through a common interface, creating consistent visibility across all dams and simplifying day-to-day operations.

Operators can now access excitation performance, diagnostics, alarms, and historian data through the same interface used for plant controls, giving teams a clearer picture of unit behavior and making it easier to identify abnormal conditions before they escalate. The improvements have contributed to fleetwide reliability levels in the 90th percentile, strengthening SRP’s ability to supply fast‑response power during periods of peak demand.

In addition, troubleshooting has become significantly faster, with SRP cutting troubleshooting time in half. High‑speed, pre‑triggered oscillography captures detailed event data up to 2560 Hz, allowing staff to determine the root cause of issues without relying on ad hoc trending or extended onsite investigation. Automation has also streamlined startup efficiency: Operators previously spent 15–20 minutes performing manual resets, but those delays have been eliminated, enabling faster restarts, even on single-operator shifts.

SRP has also reduced costs. Operations and maintenance expenses are down by approximately 30%, driven by platform standardization, reduced spare parts inventory, and simplified workforce training.

SRP has improved its cybersecurity posture, as well, thanks to standardized infrastructure, integrated excitation assets, and aligned patch management. This better positions the organization to meet evolving regulatory requirements and maintain secure operations across its hydropower fleet.

Executing the project efficiently was a priority. SRP completed excitation change‑outs in just 10–12 days per unit, nearly half the typical duration, through detailed planning, streamlined cabinet designs, and coordinated Factory Acceptance Testing and commissioning. SRP’s crews performed most of the installation work, supported by Emerson’s onsite engineering.

Another major contributor to project success was the integration of modern protection systems, including SEL-2664 relays for ground‑fault detection and SEL‑751 relays for exciter‑transformer overcurrent protection. Upgraded RTDs now monitor transformer winding temperatures with greater accuracy, strengthening equipment protection and enabling earlier intervention when abnormal conditions arise.

Pumped storage units also benefited from custom patches developed by Emerson to support specialized operational modes at Horse Mesa Unit 4 and Mormon Flat Unit 2. Because these units share generator step‑up transformers, precise logic coordination was needed to correctly manage reactive compensation, limiter behavior, and power system stabilizer functionality.

Additionally, the upgrade introduced an automatic exciter reset feature that triggers after external trips, which is an especially valuable improvement for remotely operated facilities where operators may need to travel between floors or respond after hours. Eliminating manual reset sequences has shortened restoration times and allowed operators to focus on identifying root causes rather than performing routine physical resets.

Together, these improvements demonstrate the long‑term value of unifying hydropower controls and excitation on a single, scalable platform. SRP now benefits from faster troubleshooting, improved startup performance, more reliable pumped storage operation, stronger cybersecurity, and lower overall O&M costs. With consistent HMIs, enhanced diagnostics, and streamlined engineering tools, SRP has reduced operational complexity and strengthened long‑term support for its hydropower assets, ensuring reliable clean‑energy generation and water delivery for years to come.

Modernizing hydropower fleets with integrated controls is an investment that delivers measurable gains in efficiency, reliability, and lifecycle performance. To learn how excitation and plant‑control integration can help you strengthen your hydropower operations, visit Emerson’s Ovation Hydroelectric Power Controls page to learn more.