A thermal contact sheet for a photovoltaic thermal collector comprises a sheet configured to provide thermal contact between a plurality of photovoltaic cells and a heat exchanger comprising a working fluid in the photovoltaic thermal collector. The sheet comprises a plurality of through holes shaped and arranged on the sheet so as to provide thermal expansion resistance of the sheet in a plurality of directions, by absorbing at least part of the thermal expansion of the sheet into the through holes. A photovoltaic thermal collector comprising a thermal contact sheet is also described.

A thermal contact sheet for a photovoltaic thermal collector comprises a sheet configured to provide thermal contact between a plurality of photovoltaic cells and a heat exchanger comprising a working fluid in the photovoltaic thermal collector. The sheet comprises a plurality of through holes shaped and arranged on the sheet so as to provide thermal expansion resistance of the sheet in a plurality of directions, by absorbing at least part of the thermal expansion of the sheet into the through holes. A photovoltaic thermal collector comprising a thermal contact sheet is also described.

A method includes obtaining a value corresponding to a current amount of power output from a solar panel; determining a value corresponding to an expected amount of power output from the solar panel; comparing the value corresponding to the current amount of power output from the solar panel and the value corresponding to the expected amount of power output from the solar panel of the device; and cleaning the solar panel responsive to determining, based on the comparing, that the value corresponding to the current amount of power output from the solar panel is less than the value corresponding to the expected amount of power output from the solar panel by at least a first threshold value

A method includes obtaining a value corresponding to a current amount of power output from a solar panel; determining a value corresponding to an expected amount of power output from the solar panel; comparing the value corresponding to the current amount of power output from the solar panel and the value corresponding to the expected amount of power output from the solar panel of the device; and cleaning the solar panel responsive to determining, based on the comparing, that the value corresponding to the current amount of power output from the solar panel is less than the value corresponding to the expected amount of power output from the solar panel by at least a first threshold value

A near-field ThermoPhotoVoltaic system comprises a hot emitter and a cold absorbing PhotoVoltaic cell separated by a small gap. The emitter emits hot photons and includes a polaritonic material that supports a surface-polaritonic mode. The PhotoVoltaic cell has a metallic back electrode and includes a semiconductor that absorbs the photons and supports guided photonic modes. The surface-polaritonic mode and the first guided photonic mode resonantly couple at a frequency slightly above the semiconductor bandgap. The system material and geometrical parameters are such that the surface-polaritonic mode and the first guided photonic mode are approximately impedance-matched, so that power is transmitted at frequencies just above the semiconductor bandgap, even for relatively large gap widths, while the power transmitted at other frequencies is relatively small, leading to high system efficiency. Also described the PhotoVoltaic cell's front electrode, which may include highly-doped semiconductor regions, thin conducting oxide or silver films, or graphene layers.

A near-field ThermoPhotoVoltaic system comprises a hot emitter and a cold absorbing PhotoVoltaic cell separated by a small gap. The emitter emits hot photons and includes a polaritonic material that supports a surface-polaritonic mode. The PhotoVoltaic cell has a metallic back electrode and includes a semiconductor that absorbs the photons and supports guided photonic modes. The surface-polaritonic mode and the first guided photonic mode resonantly couple at a frequency slightly above the semiconductor bandgap. The system material and geometrical parameters are such that the surface-polaritonic mode and the first guided photonic mode are approximately impedance-matched, so that power is transmitted at frequencies just above the semiconductor bandgap, even for relatively large gap widths, while the power transmitted at other frequencies is relatively small, leading to high system efficiency. Also described the PhotoVoltaic cell's front electrode, which may include highly-doped semiconductor regions, thin conducting oxide or silver films, or graphene layers.

Systems and methods are disclosed for intelligent circuit control for solar panel systems. In one embodiment, an example method may include determining, by a controller, that a first electrical output of a first solar panel configured to charge a plurality of rechargeable batteries is greater than a second electrical output of a second solar panel configured to charge the plurality of rechargeable batteries, and causing the second solar panel to be disconnected from the plurality of rechargeable batteries. Example methods may include determining that a voltage potential of the plurality of rechargeable batteries is greater than a total output voltage, where the total output voltage is a sum of the first electrical output and the second electrical output, and causing a connection between the plurality of rechargeable batteries to be changed from a series connection to a parallel connection based at least in part on the first electrical output.

Systems and methods are disclosed for intelligent circuit control for solar panel systems. In one embodiment, an example method may include determining, by a controller, that a first electrical output of a first solar panel configured to charge a plurality of rechargeable batteries is greater than a second electrical output of a second solar panel configured to charge the plurality of rechargeable batteries, and causing the second solar panel to be disconnected from the plurality of rechargeable batteries. Example methods may include determining that a voltage potential of the plurality of rechargeable batteries is greater than a total output voltage, where the total output voltage is a sum of the first electrical output and the second electrical output, and causing a connection between the plurality of rechargeable batteries to be changed from a series connection to a parallel connection based at least in part on the first electrical output.

A receiver for solar concentrating systems including a container including at least one transparent wall configured to receive solar rays from a solar concentrator and defining at least one cavity housing, a conversion module configured to convert solar energy taken from the solar rays into thermal and/or electrical energy and housed within part of the cavity close to the wall and separated from the wall by a slot, and transparent optical gel housed within the cavity and configured to completely occupy at least the slot to shield the conversion module.

A receiver for solar concentrating systems including a container including at least one transparent wall configured to receive solar rays from a solar concentrator and defining at least one cavity housing, a conversion module configured to convert solar energy taken from the solar rays into thermal and/or electrical energy and housed within part of the cavity close to the wall and separated from the wall by a slot, and transparent optical gel housed within the cavity and configured to completely occupy at least the slot to shield the conversion module.