In order to complete the loop of the LVSS, the end users are given a display, free of charge, which enables them to constantly monitor their power consumption. During a power capacity constraint period, the LVSS network control is able to communicate and alert the end user of such constraint. The system then requests a reduction in power consumption by sending a visual and audible alarm, via the display, to the end user. The end user complies by reducing non-essential loads, e.g. switching off heaters, geysers etc. The display gives immediate feedback about the reduction and compliance with the request by showing the instantaneous usage of power.
The LVSS is capable of temporarily suspending power to a specific non-compliant user for the specified constraint period, after which full power is automatically restored. Should power to a house be temporarily suspended due to non-compliance, either because the consumer did not reduce power within the specified required time, or the customer was not at home, full power may be restored if the customer sends an SMS which requests the LVSS backend to restore power. Following this, the above outlined cycle will be repeated.
Image 2: Load limiting process (click image to enlarge)
*MV = Medium Voltage
*LV = Low Voltage
*PLC = Power Line Carrier
*GPRS = General Packet Radio Service
** Times are Utility-specific
The devices installed to critical users such as traffic lights or emergency institutions such as hospitals may be programmed so as not to be affected by a load limiting instruction, hence such installations may be exempt from load limiting.