First Advisor
Robert Bass
Term of Graduation
January 2026
Date of Publication
6-1-2026
Document Type
Thesis
Language
English
Subjects
conformance, cta-2045, distributed energy resource, flexible loads, grid services, heat pump water heater
Physical Description
1 online resource ( pages)
Abstract
Residential flexible loads, such as heat pump water heaters, have great potential for grid reliability services; however, their effectiveness depends on reliable performance in response to coordinated grid service requests. While the ANSI/CTA-2045-B protocol standardizes communication, it does not mandate specific functional behaviors, creating a mismatch in which the device may comply with the communication protocol but fail to meet performance expectations. This manuscript demonstrates the need for a ANSI/CTA-2045-B implementation guide by quantifying these discrepancies through gray-box conformance testing of market-available units followed by large-scale simulations.
Field testing results revealed a significant conformance gap. Tested units exhibited an average Energy Take reporting error of 123%, with some heat pump models reaching errors as high as 337%. Reporting errors undermine the ability of load managing entities to reliably predict available capacity for grid services. To illustrate the system-level impact of these design choices, the work presents the results of large-scale simulation of 409 uniquely modeled heat pump water heaters using the object-oriented controllable high-resolution residential energy, OCHRE, tool. Results indicate that relative to a 130°F baseline, a 125°F shed setpoint achieves energy reductions ranging from 50-85% over a 4-hour event, while a 120°F shed setpoint achieves energy reductions between 73% and 88% depending on the deadband width. The study quantifies load aggregation reliability, finding that the 95% confidence interval for power consumption uncertainty converges from a 0.39 p.u. difference at N=5 units to just 0.03 p.u. at N=500 units--a 92% reduction in uncertainty, suggesting the need for robust demand response program participation.
Rather than requiring strict implementation of a specific configuration, this work provides a roadmap that allows manufacturers to maintain design freedom while ensuring their products contribute meaningfully to grid stability. By establishing the causal link between device-level parameters and system-level performance, this manuscript offers a quantitative reference to guide manufacturers in designing predictable, grid-firm assets. Enhanced device predictability allows load aggregators to more effectively coordinate these resources as reliable, flexible loads. These improvements facilitate the deferral of expensive peaking generators, providing utilities with a low-cost mechanism for maintaining grid stability.
Rights
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Recommended Citation
Paresa, Dana Kahiwahiwa, "Heat Pump Water Heater CTA-2045 Implementation Guidance for Maximizing Demand Response Impact" (2026). Dissertations and Theses. Paper 7107.