The bollard is DC (direct current) powered by lithium batteries that are charged by sunlight.
Sunlight is converted into power by the photovoltaic (PV) cell on top of the bollard and in turn charges the battery during the day. A charge controller regulates the charging of the batteries that should not be overcharged nor extremely discharged to prolong their life (cycle times).
The PV cell acts as the sensor to trigger the switch on and off. With the sunlight hitting the PV from dawn, the system, switches off the light. Sensing that no voltage from sunlight, the light switch is also activated to on mode.
As the bollards are stand-alone system (unwired from AC outlets) of photovoltaic lighting for open spaces, they are movable with ease for versatility of use.