Apparatuses and Methods to Reduce Safety Risks Associated with Photovoltaic Systems

Abstract

Apparatuses and methods to reduce safety risks associated with photovoltaic systems by providing a safety switch on a photovoltaic panel. In one embodiment, a photovoltaic panel includes: at least one photovoltaic cell; a connector to output energy from the photovoltaic panel; and a switch coupled between the at least one photovoltaic cell and the connector. The switch is configured to disconnect the at least one photovoltaic cell from the connector during installation of the photovoltaic panel, and to connect the at least one photovoltaic cell with the connector after installation of the photovoltaic panel.

What is claimed is: 
     
         1 . A photovoltaic panel, comprising:
 a plurality of photovoltaic cells;   at least one connection terminal configured on the photovoltaic panel to output electricity from the photovoltaic panel;   a voltage module to adjust an output of the plurality of photovoltaic cells;   a circuit configured to detect a watchdog signal from a controller; and   a switch coupled between the voltage module and the connection terminal to selectively provide the output through the switch to the connection terminal, the switch configured to disconnect the output in absence of the watchdog signal.   
     
     
         2 . The photovoltaic panel of  claim 1 , further comprising:
 a further circuit configured to detect a load from an inverter, the switch configured to disconnect the output in absence of the load detected by the further circuit.   
     
     
         3 . The photovoltaic panel of  claim 2 , further comprising:
 a junction box to host the connector, wherein the switch is integrated in the junction box.   
     
     
         4 . The photovoltaic panel of  claim 1 , wherein the switch comprises a semiconductor switch. 
     
     
         5 . The photovoltaic panel of  claim 4 , wherein the semiconductor switch comprises a Field-Effect Transistor (FET). 
     
     
         6 . The photovoltaic panel of  claim 1 , wherein the switch comprises a relay. 
     
     
         7 . The photovoltaic panel of  claim 1 , wherein the switch comprises an optical sensor to control a state of the switch. 
     
     
         8 . The photovoltaic panel of  claim 1 , wherein the switch comprises a reed switch. 
     
     
         9 . The photovoltaic panel of  claim 1 , wherein the voltage module outputs an alternating current (AC) output. 
     
     
         10 . A photovoltaic panel, comprising:
 at least one photovoltaic cell;   a connector to output energy generated by the at least one photovoltaic cell of the photovoltaic panel; and   a switch coupled between the at least one photovoltaic cell and the connector, the switch controlled via a periodic signal from a remote unit;   wherein when the periodic signal is present, the switch connects the at least one photovoltaic cell to the connector; and   wherein when the periodic signal is timed-out, the switch disconnects the at least one photovoltaic cell from the connector.   
     
     
         11 . The photovoltaic panel of  claim 10 , further comprising:
 a further circuit configured to detect a load from an inverter;   wherein the switch is further configured to disconnect the at least one photovoltaic cell from the connector in absence of the load detected by the further circuit.   
     
     
         12 . The photovoltaic panel of  claim 10 , further comprising:
 a watchdog circuit to control the switch; and   a junction box to host the connector, the switch and the watchdog circuit.   
     
     
         13 . The photovoltaic panel of  claim 10 , further comprising:
 a controller unit to control the switch; and   a voltage module to adjust an output of at least one photovoltaic cell.   
     
     
         14 . The photovoltaic panel of  claim 10 , wherein the signal is connected to the photovoltaic panel via a wire from a location remote from the photovoltaic panel. 
     
     
         15 . A photovoltaic panel, comprising:
 a plurality of photovoltaic cells;   at least one connection terminal configured on the photovoltaic panel to output electricity from the photovoltaic panel;   a voltage module to adjust an output of the plurality of photovoltaic cells;   a circuit to monitor a signal transmitted from a location remote from the photovoltaic panel; and   a switch coupled between the voltage module and the connection terminal to selectively provide the output through the switch to the connection terminal, the switch configured to disconnect the output based on a result of the circuit monitoring the signal.   
     
     
         16 . The photovoltaic panel of  claim 15 , wherein the signal is connected to the photovoltaic panel via wires from the location remote from the photovoltaic panel. 
     
     
         17 . The photovoltaic panel of  claim 15 , wherein the switch is configured to disconnect the output when the signal is timed-out or absent. 
     
     
         18 . The photovoltaic panel of  claim 17 , wherein the signal is a periodic signal. 
     
     
         19 . The photovoltaic panel of  claim 15 , further comprising:
 a further circuit configured to detect a load from an inverter, the switch configured to disconnect the output in absence of the load detected by the further circuit.   
     
     
         20 . The photovoltaic panel of  claim 15 , further comprising:
 a junction box to host the connection terminal, the switch and the circuit.