Electrical Service Panel Capacity in California Households with Insights for Equitable Building Electrification

Decarbonizing the U.S. housing stock necessitates upgrading building infrastructure, including replacing electrical service panels. The scale of this effort remains uncertain. Panels, customer-owned hardware connecting new electrical loads to utility service, must be assessed for existing capacity to understand potential load additions and necessary replacements for full electrification. Replacement likelihood may be higher for homes with smaller service panel ratings (e.g., 100A or less), incurring additional costs and planning burdens that hinder affordability. Two methods for assessing panel capacity in California’s single-family housing stock are explored: LBNL's field data-based machine learning model applied to ResStock metadata, and UCLA's as-built panel estimates and replacement prediction based on permit database mining. Both methods estimate panel distributions similarly, showing 200A panels as most common (39-47%), followed by 100A panels (32-33%), with smaller (<100A) and larger (201+A) panels being less common. Analysis indicates smaller, older homes and those facing equity challenges are more likely to have 100A or lower panels, suggesting future research should focus on evaluating electrical infrastructure in these homes.