dumpload

Dumpload, often written as dump load, refers to a simple electrical device or circuit used to absorb excess electrical power in a power system. It is commonly employed in off‑grid renewable energy installations and other situations where a source can generate more energy than the immediate load can consume, particularly to protect energy storage devices from overcharging or overvoltage.

Operation and function: A dump load is connected to the power source through a control system, such as a solar charge controller or an inverter with a dump function. The controller monitors battery voltage or state of charge and, when predefined thresholds are reached, diverts current into the dump load. The surplus energy is converted into heat in the dump load element, which is typically a resistive device such as a heater or immersion heater.

Applications: In solar photovoltaic systems with battery storage, dump loads help regulate charging when there is abundant sunshine and little demand. Common dump-load devices include water heaters, space heaters, or other resistive heaters sized to dissipate the expected surplus power. The concept is also used in wind or micro-hydro setups and in some grid-tied configurations to prevent overgeneration from damaging equipment.

Design considerations: Key factors include the expected surplus power, system voltage, and the duty cycle of the dump load. Important design concerns are wattage rating, thermal management, safe enclosure, and protection such as fuses or circuit breakers. Because energy is wasted as heat, choosing an appropriately sized and well-ventilated dump load is essential for efficiency and safety.

See also: dump resistor, load management, battery management system.