including a panel 10 and fluid conducting pipes or tubing 12 the panel 10 comprises a number of collecting plates 14 disposed to lie substantially in a single plane and in edge to edge relation as shown the collector plates 14 may be of any suitable material which will absorb and conduct heat when subjected to solar radiation aluminum steel and copper are among the many materials particularly suitable for the purpose the plates may have their upper surface coated or painted with any suitable black material to provide high heat absorption as is well known a coil of tubing 12 or arrangement of pipes is located in heat conducting relation to the plates and conducts a flow of water or other fluid which becomes heated when heat is generated in the plates 14 by solar radiation and is transmitted through the walls of the tubing 12 to the fluid such heated fluid may be utilized for domestic use such as for heating a building heating hot water for in house use heating water in a swimming pool or for other selected uses as desired the assembled panel 10 may be located in a suitable box or tray 16 as is well known which box has an open upper side covered by a transparent pane 18 whereby solar radiation may pass to the collector plates 14 of the panel 10 insulating material 20 may be.