Multi-tier, foldable photovoltaic roof and method

A photovoltaic, PV, screen to be used to cover a greenhouse, the PV screen comprising:

• a first PV panel including plural PV cells configured to transform solar energy into electrical energy;
• a second PV panel including plural PV cells configured to transform solar energy into electrical energy;
• a connecting mechanism configured to suspend each of the first and second PV panels from a hanging wire, the connecting mechanism including a bracket and first and second fabric layers, the first fabric layer connecting the first PV panel to the bracket and the second fabric layer connecting the second PV panel to the bracket;
• and
• an electrical connection mechanism configured to electrically connect the first PV panel to the second PV panel,
• wherein the electrical connection mechanism includes an electrical cable that extends through each of the first and second fabric layers.

A structure with a multi-tier foldable roof, the structure comprising:

• plural walls that define an enclosure;
• and
• the multi-tier foldable roof that covers the enclosure,
• wherein the multi-tier foldable roof comprises:
• a climate layer configured to close the enclosure and also configured to control temperature and humidity of the enclosure;
• a PV screen having plural PV panels, each PV panel configured to include plural PV cells;
• and
• an outer layer configured to protect the PV screen from soiling,
• wherein the climate layer, the PV screen and the outer layer are spaced apart from each other with a given distance (H), and
• wherein each of the climate layer, the PV screen and the outer layer is configured to independently change from a retracted state to an expanded state.