) The operation of the SPA solar collector is very simple 2) Solar absorption: Solar radiation is absorbed by the solar tubes And converted into heat 2) Solar heat transfer: Heat pipes conduct the heat from within the solar Tube up to the header pipe 3) Solar energy storage: Water is circulated through the header, via Intermittent pump cycling. Each time the water circulates through the Header, the temperatures is raised by 5-10oC /9-18oF. Throughout the day, the water in the storage Tank is gradually heated