A solar collector includes a box shaped collection space bounded by a rectangular bottom (10), a frame (12), and an outer rectangular glass pane (14). The box shaped collection space includes therein an inner rectangular glass pane (16) that is disposed in a first direction from the bottom and is separated from the outer rectangular glass pane by spacers (18). An absorber sheet (20) and at least one fluid conducting riser (22) are positioned intermediate of the bottom and the inner rectangular glass pane. At least two ventilation caps (30) extend in overlying relation of respective corners of the solar collector. Inner sides (32I) of the ventilation caps include a pattern (34P, 34Z) of air ventilation passages that provide at least one ventilation channel that extends from outside the collector space to between the inner and outer rectangular glass panes.

A solar collector includes a box shaped collection space bounded by a rectangular bottom (10), a frame (12), and an outer rectangular glass pane (14). The box shaped collection space includes therein an inner rectangular glass pane (16) that is disposed in a first direction from the bottom and is separated from the outer rectangular glass pane by spacers (18). An absorber sheet (20) and at least one fluid conducting riser (22) are positioned intermediate of the bottom and the inner rectangular glass pane. At least two ventilation caps (30) extend in overlying relation of respective corners of the solar collector. Inner sides (32I) of the ventilation caps include a pattern (34P, 34Z) of air ventilation passages that provide at least one ventilation channel that extends from outside the collector space to between the inner and outer rectangular glass panes.

A multifunction flat plate heat exchanger including a heat exchanging flat plate, a spectrum selectivity absorption layer, a light transmissive layer, at least one heat-conductive structure, and at least one airflow driving device is provided. The heat exchanging flat plate has a first plate surface, a second plate surface and a pipe tunnel located between the first plate surface and the second plate surface. The spectrum selectivity absorption layer covers the first plate surface. The light transmissive layer covers the spectrum selectivity absorption layer, and the light transmissive layer and the first plate surface are respectively located at two opposite sides of the spectrum selectivity absorption layer. The heat-conductive structure is disposed on the second plate surface. The airflow driving device is disposed at one side of the heat exchanging flat plate and the heat-conductive structure.

A multifunction flat plate heat exchanger including a heat exchanging flat plate, a spectrum selectivity absorption layer, a light transmissive layer, at least one heat-conductive structure, and at least one airflow driving device is provided. The heat exchanging flat plate has a first plate surface, a second plate surface and a pipe tunnel located between the first plate surface and the second plate surface. The spectrum selectivity absorption layer covers the first plate surface. The light transmissive layer covers the spectrum selectivity absorption layer, and the light transmissive layer and the first plate surface are respectively located at two opposite sides of the spectrum selectivity absorption layer. The heat-conductive structure is disposed on the second plate surface. The airflow driving device is disposed at one side of the heat exchanging flat plate and the heat-conductive structure.

A modular composite panel comprised of a solar photovoltaic panel, a solar thermal collector panel, and an engineered torsion box containing a layer of insulation. Multiple composite panels can form a roof when installed in an array, with panels abutting and situated side-by-side on a structural frame or other suitable support system. A composite panel may span between structural members without requiring intermediate support. A composite panel array can provide weather protection, electricity, and hot water to an enclosed or unenclosed space below. Together with insulated walls, the array of composite panels can provide thermal insulation to an enclosed space below.

A modular composite panel comprised of a solar photovoltaic panel, a solar thermal collector panel, and an engineered torsion box containing a layer of insulation. Multiple composite panels can form a roof when installed in an array, with panels abutting and situated side-by-side on a structural frame or other suitable support system. A composite panel may span between structural members without requiring intermediate support. A composite panel array can provide weather protection, electricity, and hot water to an enclosed or unenclosed space below. Together with insulated walls, the array of composite panels can provide thermal insulation to an enclosed space below.

A solar collector housing that is opened and closed without tools includes structure for accommodating temperature-related expansion and contraction of a polymer absorber housed within the collector. The housing includes a transparent cover, a frame for holding the transparent cover, and a base. The cover, frame and base collectively define a hollow interior within which the polymer absorber is positioned. A plurality of latches is secured to an exterior of the frame. The frame and base are pivotally connected to one another when the latches are open so that the collector housing can be opened. The housing cannot be opened when the latches are closed. A pair of variable gate closure components are positioned in slots formed in a second end of the collector and enable the polymer absorber to expand and contract without placing stress on the absorber tubes.

A solar collector housing that is opened and closed without tools includes structure for accommodating temperature-related expansion and contraction of a polymer absorber housed within the collector. The housing includes a transparent cover, a frame for holding the transparent cover, and a base. The cover, frame and base collectively define a hollow interior within which the polymer absorber is positioned. A plurality of latches is secured to an exterior of the frame. The frame and base are pivotally connected to one another when the latches are open so that the collector housing can be opened. The housing cannot be opened when the latches are closed. A pair of variable gate closure components are positioned in slots formed in a second end of the collector and enable the polymer absorber to expand and contract without placing stress on the absorber tubes.

A reflective concentrator can include a primary reflector and a secondary reflector located radially outward of the primary reflector. The primary reflector can be a rotationally-symmetric, convex conical shape, radial sections of which may include an off-axis parabolic reflector with a focal point radially outward of the primary reflector. A secondary reflector may be located radially outward of the primary reflector, and may include a rotationally symmetric section of a toroidal space surrounding the primary reflector. In some embodiments, the secondary reflector may be convex or concave. Incident sunlight generally aligned with a rotational axis of symmetry of the primary reflector may be reflected off of the primary reflector, off of the secondary reflector, and back towards a point near the central peak of the primary reflector. The reflective concentrator may be aerodynamically stable, and may include an aerodynamic fairing on its read side to further increase the aerodynamic stability of the structure.

A reflective concentrator can include a primary reflector and a secondary reflector located radially outward of the primary reflector. The primary reflector can be a rotationally-symmetric, convex conical shape, radial sections of which may include an off-axis parabolic reflector with a focal point radially outward of the primary reflector. A secondary reflector may be located radially outward of the primary reflector, and may include a rotationally symmetric section of a toroidal space surrounding the primary reflector. In some embodiments, the secondary reflector may be convex or concave. Incident sunlight generally aligned with a rotational axis of symmetry of the primary reflector may be reflected off of the primary reflector, off of the secondary reflector, and back towards a point near the central peak of the primary reflector. The reflective concentrator may be aerodynamically stable, and may include an aerodynamic fairing on its read side to further increase the aerodynamic stability of the structure.