Abstract: An energy storage tank defining a tank volume for heat transfer fluid and comprising a partition dividing the tank volume into a first volume and a second volume, wherein the partition is movable to/from any position between a minimum energy storage position corresponding to a minimum second volume, and a maximum energy storage position corresponding to a maximum second volume, the energy storage tank further comprising a biasing device being arranged such that movement of the partition away from the minimum energy storage position corresponds to storing energy in the biasing device, and movement towards the minimum energy storage position corresponds to releasing energy from the biasing device.

Abstract: A method in a wireless process control system for reducing power consumption of a sensor node of the wireless process control system. The wireless process control system further includes a controller in wireless communication with the sensor node wherein the sensor node is in a sleep mode. The method includes the steps of: predicting based on an error signal, when sensor measurement data is needed from the sensor node and determining an instant of time for communication between the controller and the sensor node based thereon; and the sensor node re-entering the sleep mode. The invention also relates to computer program products and a controller.

Abstract: A method in a wireless process control system for reducing power consumption of a sensor node of the wireless process control system. The wireless process control system further includes a controller in wireless communication with the sensor node wherein the sensor node is in a sleep mode. The method includes the steps of: predicting based on an error signal, when sensor measurement data is needed from the sensor node and determining an instant of time for communication between the controller and the sensor node based thereon; and the sensor node re-entering the sleep mode. The invention also relates to computer program products and a controller.