Photovoltaic systems with voltage limiting devices
Granted: February 26, 2019
Patent Number:
10218182
A photovoltaic system includes voltage limiting devices that are connected in series. A voltage limiting device clips a corresponding photovoltaic string to limit a voltage of the photovoltaic string. Unclipping of clipped photovoltaic strings is coordinated by a central controller or in a distributed fashion by the voltage limiting devices based on monitored string conditions.
Voltage breakdown device for solar cells
Granted: February 26, 2019
Patent Number:
10217880
Voltage breakdown devices for solar cells are described. For example, a solar cell includes a semiconductor substrate. A plurality of alternating N-type and P-type semiconductor regions is disposed in or above the substrate. A plurality of conductive contacts is coupled to the plurality of alternating N-type and P-type semiconductor regions. A voltage breakdown device is disposed above the substrate. The voltage breakdown device includes one of the plurality of conductive contacts in…
Tri-layer semiconductor stacks for patterning features on solar cells
Granted: February 26, 2019
Patent Number:
10217878
Tri-layer semiconductor stacks for patterning features on solar cells, and the resulting solar cells, are described herein. In an example, a solar cell includes a substrate. A semiconductor structure is disposed above the substrate. The semiconductor structure includes a P-type semiconductor layer disposed directly on a first semiconductor layer. A third semiconductor layer is disposed directly on the P-type semiconductor layer. An outermost edge of the third semiconductor layer is…
Mitigation of arc flash hazard in photovoltaic power plants
Granted: February 19, 2019
Patent Number:
10211625
Arc flash mitigation devices are employed to protect personnel during maintenance of photovoltaic inverters. During normal operation, an alternating current (AC) output of a photovoltaic inverter is coupled to a low voltage winding of a step up transformer through a bus-bar (e.g., an electrically conductive interconnect), which has higher current rating than a fuse. During maintenance, the bus-bar is replaced with the fuse. The fuse may be employed in conjunction with a switch. The…
Solar cell contact formation using laser ablation
Granted: February 19, 2019
Patent Number:
10211349
The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the…
Thick damage buffer for foil-based metallization of solar cells
Granted: February 5, 2019
Patent Number:
10199521
Approaches for the foil-based metallization of solar cells and the resulting solar cells are described. A method involves patterning a first surface of a metal foil to provide a plurality of alternating grooves and ridges in the metal foil. Non-conductive material regions are formed in the grooves in the metal foil. The metal foil is located above a plurality of alternating N-type and P-type semiconductor regions disposed in or above a substrate to provide the non-conductive material…
Sun tracking solar energy collection system with torsion lock
Granted: January 8, 2019
Patent Number:
10174970
A rotation locking device for use in a row-level sun tracking solar energy collection system includes a housing, a first locking member, a second locking member, and an actuator. The housing is configured to be mounted to a pile and configured to permit a torque tube to extend through the housing. The first locking member has a plurality of circumferentially spaced projections attached to and rotatable with the torque tube. The second locking member is connected to the housing and has a…
Snap-on rail assembly
Granted: January 8, 2019
Patent Number:
10177704
A mounting assembly to mount frames on a mounting surface, the mounting assembly having rails that supports the frames, each rail having an internal side adjacent with an internal recess, and an external side opposite to the internal side with lip; and roof mounting assemblies to affix the rails onto the mounting surface. Each mounting assembly having a mounting block that is fixable to the mounting surface, a mounting plate that is fixable to the mounting block, and a pair rail snap…
Bonds for solar cell metallization
Granted: January 8, 2019
Patent Number:
10177270
A solar cell can include a substrate and a semiconductor region disposed in or above the substrate. The solar cell can also include a conductive contact disposed on the semiconductor region with the conductive contact including a conductive foil bonded to the semiconductor region.
Laser foil trim approaches for foil-based metallization for solar cells
Granted: January 8, 2019
Patent Number:
10177260
Laser foil trim approaches for foil-based metallization of solar cells, and the resulting solar cells, are described. For example, a method of fabricating a solar cell includes attaching a metal foil sheet to a surface of a wafer to provide a unified pairing of the metal foil sheet and the wafer, wherein the wafer has a perimeter and the metal foil sheet has a portion overhanging the perimeter. The method also includes laser scribing the metal foil sheet along the perimeter of the wafer…
Photovoltaic module mount
Granted: January 1, 2019
Patent Number:
10171027
Mounting components of photovoltaic (PV) modules and PV module assemblies are described, including PV module couplings and PV module mounting chassis. In an example, a PV module includes a PV module coupling having a toe portion extending from a PV module frame, and a PV module mounting chassis includes a toe slot to receive the toe. The toe and toe slot construction allows for the PV module frame to be assembled to the PV module mounting chassis without using tools, and thus, permits a…
Solar cell having an emitter region with wide bandgap semiconductor material
Granted: January 1, 2019
Patent Number:
10170657
Solar cells having emitter regions composed of wide bandgap semiconductor material are described. In an example, a method includes forming, in a process tool having a controlled atmosphere, a thin dielectric layer on a surface of a semiconductor substrate of the solar cell. The semiconductor substrate has a bandgap. Without removing the semiconductor substrate from the controlled atmosphere of the process tool, a semiconductor layer is formed on the thin dielectric layer. The…
Solar cells with improved lifetime, passivation and/or efficiency
Granted: January 1, 2019
Patent Number:
10170642
A method of fabricating a solar cell can include forming a dielectric region on a silicon substrate. The method can also include forming an emitter region over the dielectric region and forming a dopant region on a surface of the silicon substrate. In an embodiment, the method can include heating the silicon substrate at a temperature above 900 degrees Celsius to getter impurities to the emitter region and drive dopants from the dopant region to a portion of the silicon substrate.
Preventing harmful polarization of solar cells
Granted: December 25, 2018
Patent Number:
10164567
In one embodiment, harmful solar cell polarization is prevented or minimized by providing a conductive path that bleeds charge from a front side of a solar cell to the bulk of a wafer. The conductive path may include patterned holes in a dielectric passivation layer, a conductive anti-reflective coating, or layers of conductive material formed on the top or bottom surface of an anti-reflective coating, for example. Harmful solar cell polarization may also be prevented by biasing a region…
Multi-layer sputtered metal seed for solar cell conductive contact
Granted: December 25, 2018
Patent Number:
10164131
Multi-layer sputtered metal seed for solar cell conductive contacts and methods of forming solar cell conductive contacts are described. In an example, a solar cell includes a substrate. A semiconductor region is disposed in or above the substrate. A conductive contact is disposed on the semiconductor region and includes a seed material stack in contact with the semiconductor region. The seed material stack includes a first aluminum layer having a first crystallinity and disposed on the…
Photovoltaic module clip
Granted: December 18, 2018
Patent Number:
10158323
A photovoltaic (PV) module clip, and methods of fastening a PV module to a structural member using the PV module clip, are described. In an example, a PV module clip includes a toe portion interconnected with several legs by a neck portion. The toe portion may be inserted through several aligned holes of a PV module frame and a mounting assembly strut to an underside of the strut. The neck portion may extend upward from the toe portion through the aligned holes to the legs above the…
Attachment of cylinders in the housing of free-piston stirling machines
Granted: December 18, 2018
Patent Number:
10156204
An improvement to a free-piston Stirling machine having a cylinder mounted within a housing. The cylinder has a flange for mounting the cylinder within the housing to a transition plate with a central opening for receiving the cylinder. An elastic rim bounds and surrounds the opening and extends in an axial direction from the plate to a crest of the rim. The crest of the rim is in contact against a first axially facing side of the cylinder flange. The interior side of the rim is…
Solderable contact regions
Granted: December 11, 2018
Patent Number:
10153384
A contact region for a semiconductor substrate is disclosed. Embodiments can include forming a seed metal layer having an exposed solder pad region on the semiconductor substrate and forming a first metal layer on the seed metal layer. In an embodiment, a solderable material, such as silver, can be formed on the exposed solder pad region prior to forming the first metal layer. Embodiments can include forming a solderable material on the exposed solder pad region after forming the first…
Solar cells having differentiated P-type and N-type architectures
Granted: November 27, 2018
Patent Number:
10141462
Methods of fabricating solar cell emitter regions with differentiated P-type and N-type region architectures, and the resulting solar cells, are described herein. In an example, a solar cell includes an N-type semiconductor substrate having a light-receiving surface and a back surface. A plurality of N-type polycrystalline silicon regions is disposed on a first thin dielectric layer disposed on the back surface of the N-type semiconductor substrate. A plurality of P-type polycrystalline…
Trench process and structure for backside contact solar cells with polysilicon doped regions
Granted: November 13, 2018
Patent Number:
10128395
A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. A trench structure separates the P-type doped region from the N-type doped region. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. The trench structure may include a textured surface for increased solar radiation collection. Among other advantages, the resulting structure increases efficiency by providing isolation between…
