Protecting residential electrical panels and service through model predictive control: A field study

TL;DR

This work tackles the barrier of electrifying older single-family homes with 100 A panels by developing and field-testing a two-level model predictive control system that coordinates a heat pump and water heater to keep total current within safe limits. The high-level controller uses scenario-based MPC on a $5$-minute horizon with multiple water-draw scenarios, while a fast low-level layer reacts every $30$ seconds to prevent current-limit violations, including defrost-cycle considerations. The approach leverages data-driven building, HP, WH, and disturbance models, together with weather forecasts, to balance comfort, cost, and current-limit safety; field results over $31$ winter days show the home remained within the $100$ A limit (with one minor 104 A spike due to a communication delay), suggesting older homes can be electrified without panel upgrades. Simulations further indicate that a second EV with Level II charging could be accommodated under the same 100 A infrastructure, implying substantial cost savings ($ ext{roughly }$ $2{,}000$–$10{,}000$) and faster adoption of electrification in aging housing stock. Overall, the study demonstrates the practical viability of using supervisory planning plus device-level control to protect electrical infrastructure during residential decarbonization, with implications for scalable deployment and regulatory alignment.$

Abstract

Residential electrification - replacing fossil-fueled appliances and vehicles with electric machines - can significantly reduce greenhouse gas emissions and air pollution. However, installing electric appliances or vehicle charging in a residential building can sharply increase its current draws. In older housing, high current draws can jeopardize electrical infrastructure, such as circuit breaker panels or electrical service (the wires that connect a building to the distribution grid). Upgrading electrical infrastructure can entail long delays and high costs, so poses a significant barrier to electrification. This paper develops and field-tests a control system that avoids the need for electrical upgrades by keeping an electrified home's total current draw within the safe limits of its panel and service. In the proposed control architecture, a high-level controller plans device set-points over a rolling prediction horizon. A low-level controller monitors real-time conditions and ramps down devices if necessary. The control system was tested in an occupied, electrified single-family house with code-minimum insulation, an air-to-air heat pump and backup resistance heat, a resistance water heater, and a plug-in hybrid electric vehicle with Level I charging. The field tests spanned 31 winter days with outdoor temperatures as low as -20 C. The control system maintained the whole-home current within the safe limits of electrical panels and service rated at 100 A, a common rating for older houses in North America, by adjusting only the temperature set-points of the heat pump and water heater. Simulations suggest that the same 100 A limit could accommodate a second electric vehicle with Level II charging. The proposed control system could allow older homes to safely electrify without upgrading electrical panels or service, saving a typical household on the order of $2,000 to $10,000.

Figures (18)

• Figure 1: The control system uses real-time measurements from the house to decide HP and WH set-points that maintain comfort and ensure safe whole-home currents.
• Figure 2: (Left) Percentage breakdown of panel sizes in four census regions EPRI. (Right) Number of panels (in millions) that require an upgrade in the case of full electrification with backup heat and electrical vehicle adoption.
• Figure 3: (Left) Different magnitudes and durations of current peaks trigger thermal vs. magnetic trips in circuit breakers. (Right) A typical panel has a main breaker and several branch circuit breakers breakerFig. This paper focuses on the main breaker.
• Figure 4: The test house is a 208 m$^2$, 1920s-era house with all-electric appliances in West Lafayette, U.S.
• Figure 5: Five-minute whole-house current over 43 baseline days. Red line: Median. Blue box: 25th to 75th percentile range. Red dots: Outliers. Without device coordination, currents were often undesirable (gray region), occasionally unsafe for older 100 A breakers (yellow), and three times would likely have tripped even a new 100 A breaker (red).