NOVELTY - The device (107) has a reflector-concentrator (104)that is formed by an inflated balloon (101), which is provided with a transparent skin (102) on and a reflecting surface on an opposite side. A solar panel (105) is placed near the focus of the reflector-concentrator. A control system (110) is configured to continuously align an axis of the reflector-concentrator with respect to the direction of the sun. The inflated balloon is filled with air lighter than gas. The inflated balloon is enclosed into an aerodynamically streamlined balloon.    USE - Device for converting solar energy into electric energy used in fixed installation such as buoy, vessel, solar farm and moving vehicle in land or ground, bottom of lake and marine environment such as ocean or sea.    ADVANTAGE - Since the reflector-concentrator is formed by inflated balloon that is placed above the ground, the reflector-concentrator and the solar panels are completely protected against environment impacts such as sand, dust, dirt, flying debris wind, vandalism and water etc. The reflector-concentrator and the tracking actuators are less expensive than the conventional concentrated solar systems. Since the spherical balloon is provided with a self aligning tail, the area of low pressure is eliminated, while allowing the sphere to freely rotate around two axes to track the sun. Since the light filter is heating the air inside of balloon, the air is heated with decreased parasitic heat in the solar panel. Since the fans can be provided inside of the chambers of the balloon, the convection of heated air is ensured inside the chambers. Hence the efficient cooling system for the solar cells is achieved. Since the balloons are tightly packed in the farm, the land occupied is less and the wind pressure on each balloon is smaller.    DESCRIPTION OF DRAWING(S) - The drawing shows an explanatory view of the reflector concentrator inside the balloon.    Inflated balloon (101)    Transparent skin (102)    Reflector-concentrator (104)    Solar panel (105)    Device for converting solar energy into electric energy (107)    Control system (110)