WS solar system is a system with variable storage volume, the aperture area of W-56
collector and storage volume are decided on the basis of hot water consumption. WS Solar
system enables to transfer the heat from solar collector to the storage continuously during
the day when the Sun shines. WS solar system can provide hot water with desired
temperature in the early morning, with the conventional back up system, for instance gas, oil
boiler, steam, electric heater. 

Payback time shall be about 4-8 years, much depended on the local conventional fuel charges and the solar utilization rate annually.