A novel method is described for water heating using stored solar heat. Solar heat is stored in an insulated tank by using scrap and inexpensive heat absorbing or heat storing materials. Stored solar heat can then be used to heat water in a storage tank by extracting the solar heat using an antifreeze liquid which in turn heat cold water in the water tank. Water temperature in the storage tank is controlled by a thermostat. When the water temperature drops below the set point on the thermostat, a circulating pump turns on and pump the cold water until it reaches the desired set temperature. Once it reaches the set point in the thermostat, the water circulation pump turns off.

A novel method is described for water heating using stored solar heat. Solar heat is stored in an insulated tank by using scrap and inexpensive heat absorbing or heat storing materials. Stored solar heat can then be used to heat water in a storage tank by extracting the solar heat using an antifreeze liquid which in turn heat cold water in the water tank. Water temperature in the storage tank is controlled by a thermostat. When the water temperature drops below the set point on the thermostat, a circulating pump turns on and pump the cold water until it reaches the desired set temperature. Once it reaches the set point in the thermostat, the water circulation pump turns off.

A novel method is described for room heating using stored solar heat. Solar heat is stored in an insulated tank by using scrap and inexpensive heat absorbing or heat storing materials. Stored heat can then be extracted by air circulation for room heating. The temperature of the room air is controlled by a thermostat. When the room temperature drops below the set point on the thermostat, a circulating air pump turns on and extract the solar heat until the room temperature air reaches the desired set temperature. Once room temperature reaches the set point in the thermostat, the air circulation pump turns off.

The method according to the invention for producing a prestressed concrete workpiece is characterized in that the prestress is created by a heat treatment, wherein the concrete and the reinforcement therefor are selected in such a way that, when cooling the concrete workpiece from an elevated temperature, the heat expansion coefficient of the concrete is less than that of the reinforcement, and in that, during cooling, the concrete and the reinforcement adhere sufficiently strongly to one another if, during cooling, the concrete is hydrated at least to such an extent in order to be able to expand the reinforcement on account of the different heat expansion coefficients, and in that the concrete, together with the reinforcement, is brought to the elevated temperature in such a way that and is hydrated during cooling at least to such an extent that it is prestressed by the reinforcement after cooling.

The method according to the invention for producing a prestressed concrete workpiece is characterized in that the prestress is created by a heat treatment, wherein the concrete and the reinforcement therefor are selected in such a way that, when cooling the concrete workpiece from an elevated temperature, the heat expansion coefficient of the concrete is less than that of the reinforcement, and in that, during cooling, the concrete and the reinforcement adhere sufficiently strongly to one another if, during cooling, the concrete is hydrated at least to such an extent in order to be able to expand the reinforcement on account of the different heat expansion coefficients, and in that the concrete, together with the reinforcement, is brought to the elevated temperature in such a way that and is hydrated during cooling at least to such an extent that it is prestressed by the reinforcement after cooling.

The invention relates to a new way of stabilizing and mounting solar panels in the form of conventional heat exchangers comprising a trough and a glass cover or of a photovoltaic panel on house walls with the aid of frames made of natural or artificial stones which are made break-resistant using fiber materials and are stabilized in such a way that the panels are also break-resistant on impact and can be mounted as self-supporting structures on a wall; furthermore, the panels in particular satisfy high standards in respect of esthetics and are low-maintenance and thus permanently appealing. Multiple solar panels comprising stone frames can form entire stone-solar panel facades.

A method for improving the efficiency of a solar heating system based on absorbing heat from solar radiation into the outer surface of a concrete wall. The heat transfer device makes use of a fluid in a tube system to transfer heat from the outside of the wall to the inside of the wall. The inside wall is then used to heat air that is passed over it, and that air is then used to heat up a heat storage system.

Photovoltaic system includes i) a first photovoltaic panel (11) comprising a first and a second edge (111, 112) between which the panel extends in length; ii) a support means (2) for supporting the first panel (11); the support means (2) being at least in part made of concrete, defining a ballast of the first panel (11) and including:a first and a second support zone (21, 22); the distance from the first edge (111) of the first zone (21) being smaller than the distance from the first edge (111) of the second zone (22);a third support zone (23) whose distance from the first edge (111) is intermediate with respect to the distance from the first edge (111) of the first and of the second support zone (21, 22);a first bracket (231) constrained to the third support zone (23) and protruding away from the third support zone (23); and a first gripping means (230) for gripping the first panel (11) supported by the first bracket (231).

The invention relates to a new way of stabilizing and mounting solar panels in the form of conventional heat exchangers comprising a trough and a glass cover or of a photovoltaic panel on house walls with the aid of frames made of natural or artificial stones which are made break-resistant using fiber materials and are stabilized in such a way that the panels are also break-resistant on impact and can be mounted as self-supporting structures on a wall; furthermore, the panels in particular satisfy high standards in respect of esthetics and are low-maintenance and thus permanently appealing. Multiple solar panels comprising stone frames can form entire stone-solar panel facades.

The structure of a concentrator mirror includes a prefabricated body of reinforced concrete, which includes a panel member having a front surface with a reflective laminar layer, and a back surface, between which a hinge axis for the rotation of the panel is defined. A pair of coaxial hollow seats are formed in the body at respective longitudinally spaced positions, to define the hinge axis together with respective spherical joints. The body includes a rib shaped counterweight appendage extending parallel to the hinge axis from the back surface of the panel member, on the side opposite the front surface, so as to bring the hinge axis in a barycentric position of the body.