Residential Electrical Service Upgrade Decision Tool

Meeting the state’s climate and clean air goals requires electrification of the existing residential housing stock. Residential electrification is often erroneously assumed to require electrical panel and service upgrades in dwellings that currently have less than 200A of capacity. Under this assumption, a substantial minority (30-40%) of all dwellings in the state of California would require costly and time-consuming panel and service upsizing, representing $25-40 billion dollars of investment. These upgrades will also impose additional stress on the electrical grid, requiring substantial upstream investments by utilities and ratepayers. This represents a major bottleneck to rapid and equitable building electrification. This path poses an especially large burden on the state’s disadvantaged communities and tenants in older single-family and multifamily housing, who are more likely to have inadequate electrical infrastructure. The proposed project’s goal is to leverage current research and practices to provide a “Residential Service Upgrade Decision Tool,” hereafter referred to as “Tool”, focused on existing residential single-family and multifamily buildings. The Tool is aimed at utilities, homeowners, contractors, regulators, and policy makers, and will include several decision-trees providing guidance on when to upsize electrical panels and service versus alternatives to manage available panel and service capacity to electrify homes. The Tool will provide differentiated information based on the intended audiences. For example, a homeowner will be able to assess the likely need for a panel/service upsizing or alternatives to avoid the same at their individual home. A contractor may use the Tool to view several scenarios for homes they typically service to estimate which of their projects will likely need panel/service upsizing or avoid it. Utility and policy makers will be able to run scenarios allowing them to estimate the potential needs at a statewide, utility specific or locational basis based on input assumptions on home size, location, existing panel capacity and likely electrification upgrades. The Tool will also be differentiated based on whether it is for a single-family home versus a multifamily building.