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 system and method for localization and calibration of a heliostat is disclosed. The system comprises a controller and a camera configured to acquire images of a plurality of heliostats. The controller and camera are configured to acquire a first image of the plurality of heliostats, move one of the plurality of heliostats, acquire a second image of the plurality of heliostats, generate a difference image by subtracting the second image from the first image, identify the heliostat that was moved based on the difference image, and calibrate the position or orientation of the heliostat based on the difference image. The difference image is generated by pixel-wise subtraction of the second image from the first image. The pixel-wise subtraction exposes the heliostat and enables the calibration of the position and/or orientation of known heliostat positions.

A system and method for localization and calibration of a heliostat is disclosed. The system comprises a controller and a camera configured to acquire images of a plurality of heliostats. The controller and camera are configured to acquire a first image of the plurality of heliostats, move one of the plurality of heliostats, acquire a second image of the plurality of heliostats, generate a difference image by subtracting the second image from the first image, identify the heliostat that was moved based on the difference image, and calibrate the position or orientation of the heliostat based on the difference image. The difference image is generated by pixel-wise subtraction of the second image from the first image. The pixel-wise subtraction exposes the heliostat and enables the calibration of the position and/or orientation of known heliostat positions.

A system comprising a structure (1) defining a volume for containing or receiving a body of water. The system further comprises a solar energy system for heating a body of water. The system comprises a solar radiation receiving unit (2) configured to receive solar radiation and configured to convert said solar radiation into heat energy. The system also comprises a barrier means (3) of varying solar radiation transmittance arranged over said solar radiation receiving unit (2). The barrier means (3) is configured to varyingly control the solar radiation receivable by said solar radiation receiving unit (2).

A device for thermal separation between a conditioned environment and at least one external environment, which comprises a wall that has at least a first active layer-like region toward the conditioned environment, a second active layer-like region toward the external environment with respect to the first active layer-like region, a first insulating layer-like region, which is interposed between the active layer-like regions, a second insulating layer-like region, which is interposed between the second active layer-like region and the external environment. The active layer-like regions accommodate channels for the outflow of heat transfer fluids, which have, during the operation of the thermal separation device, temperatures that on average are different through the thickness of the wall.

Technologies and implementations for reflective roofs are generally disclosed.

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.

A method for controlling stagnation in a solar collector, comprises: providing an solar energy absorbing substrate and a first layer; providing a second layer disposed between the first layer and the solar energy absorbing substrate; coupling an actuator to the solar energy absorbing substrate; and expanding the actuator when the solar collector is exposed to a stagnation temperature to form a gap between the first layer and the second layer.

Building-integrated photovoltaic devices can be provided, which function as sensors, wherein the output parameters from the device are used to provide information about light intensity and ambient temperature, in addition to providing power, to an intelligent building energy management system.