Solar Water Heater System in Vadodara. Geetanjali Engineers. How does the solar water heater system work? The Sun's rays fall on the collector panel (a component of solar water heating system). A black absorbing surface (absorber) inside the collectors absorbs solar radiation and transfers the heat energy to water flowing through it. Heated water is collected in a tank which is insulated to prevent heat loss. Solar panel in Vadodara.