Energy-Aware Electric Hot Water Systems with Topology-Modeled Control and Service-Level Degradation

This defensive publication discloses a general class of systems for allocating limited locally available electrical energy to domestic or service hot water generation and related electrically controllable thermal loads. The disclosed systems may operate in residential, multi-unit, or light-commercial settings and may draw energy from photovoltaic generation, battery storage, the utility grid, generators, or any combination thereof. A controller determines an allowed service level for one or more thermal loads from an availableenergy state that can include battery state of charge, stored energy, available discharge power, predicted source availability, import limits, reserve obligations, tariffs, or other operating constraints. The service level may be implemented by direct heater control, indirect upstream power limitation, hydraulic flow control, mixing, staged load selection, charge scheduling of thermal buffers, or equivalent actuation paths. A machine-readable topology model is disclosed for design, simulation, commissioning, and runtime control, with a directed graph as one embodiment and other equivalent connectivity or constraint representations expressly included. Concrete embodiments include an AC-coupled commercially available instantaneous water heater, a DC-direct heater connected to the battery bus, and hybrid architectures combining both. This disclosure is published as prior art and dedicated to the public domain to prevent patenting of the described methods, systems, and combinations.