Photovoltaic-thermal (PVT) module with storage tank and associated methods

A photovoltaic-thermal (PVT) module system, comprising:

• a photovoltaic module including a layer of photovoltaic material, the layer of photovoltaic material having a front side exposed to incident radiation and an opposite back side;
• a thermal unit thermally coupled to the back side of the layer of photovoltaic material, said thermal unit including one or more channels through which a liquid flows, wherein a portion of the incident radiation is converted into electricity by the layer of photovoltaic material and a portion of the incident radiation is simultaneously converted to heat for increasing the temperature of the liquid;
• and
• a ballast beneath the thermal unit for stabilizing the PVT module system in an installed location, said ballast comprising a liquid storage tank connected to the thermal unit and in fluid communication with the one or more channels in the thermal unit for receiving and storing liquid heated by the thermal unit, said liquid storage tank having internal walls in contact with the liquid when the PVT module system is in use;
• wherein the photovoltaic module and the thermal unit are detachably mounted on the liquid storage tank, and wherein the liquid storage tank is openable to receive and store the photovoltaic module and the thermal unit inside the internal walls of the liquid storage tank in place of the liquid when the PVT module system is in a disassembled state.