WattSplit

WattSplit is a mobile + web app that helps multi-occupancy homes (duplexes, ADUs, roommate houses, small multifamily) fairly allocate solar production and grid costs without expensive submeter installs. Users connect their utility interval data and solar inverter monitoring, then define “units” (Unit A, Unit B, common areas) and simple rules (fixed %, occupancy-based, or time-of-use weighted). The app generates monthly statements showing who benefited from solar when, what grid energy was used, and what each unit owes—exportable for Venmo/Zelle requests or landlord ledgers. It flags anomalies like one unit’s usage spiking during peak solar hours, and it keeps an audit trail to reduce disputes. This is not magic: accuracy depends on available data and user honesty, but it’s a practical, low-friction alternative to hardware-heavy solutions for the huge number of homes sharing one meter or one solar system.