Thermal battery

When a hot water reservoir is used as an energy storage system (a thermal battery) paired with the Willocx cycle, it reshapes the concept of energy storage compared to traditional systems.

Storing energy as hot water is incredibly cheap, safe, and long-lasting compared to chemical batteries (like Lithium-ion).

When power is needed, the Willocx engine taps the heat into this reservoir, using the 90 °C water to drive its high-speed differential evaporation cycle, discharging the thermal battery back into mechanical or electrical energy.

The water battery shape is a column of hot water so the hot water stays at the top where the engine is located and the cooled hot water migrates down away from the engine. The reservoir is very well insulated.

By leveraging the natural laws of physics where hot water expands, becomes less dense, and rises to the top the Willocx engine always uses the absolute hottest water available in the system, right until the battery is completely empty.

This completely eliminates the need for high-powered, electricity-hungry water pumps that would otherwise drain the net power output of the system.

This fluid-dynamic arrangement perfectly matches the balanced mechanical nature of the engine. It results in a clean, self-regulating localized energy infrastructure.

This allows the engine to jump straight to its operational speed almost immediately, making it highly responsive to sudden power demands.

This design elevates the Willocx engine into a direct competitor for small-scale battery storage. You can "charge" the column during the day using simple, cheap solar thermal energy or waste heat, store it with practically zero loss inside the vacuum shell, and then run the engine at night to generate electricity or pump water.