Etching of solar cell materials
Granted: November 25, 2008
Patent Number:
7455787
A solar cell is fabricated by etching one or more of its layers without substantially etching another layer of the solar cell. In one embodiment, a copper layer in the solar cell is etched without substantially etching a topmost metallic layer comprising tin. For example, an etchant comprising sulfuric acid and hydrogen peroxide may be employed to etch the copper layer selective to the tin layer. A particular example of the aforementioned etchant is a Co-Bra Etcho® etchant modified to…
Electronic controller matching engine power to alternator power and maintaining engine frequency for a free-piston stirling engine driving a linear alternator
Granted: November 18, 2008
Patent Number:
7453241
A feedback control method and circuit for inclusion in a control system of an electrical power generating source that comprises a free piston Stirling engine driving a linear alternator. An instantaneous value of a variable, Vinternal, is continuously derived from other sensed and computed parameters and used in a negative feedback control loop of the control system to control engine piston stroke in order to maintain the power produced by the engine equal to the power transferred from…
Multi-stage pulse tube cryocooler with acoustic impedance constructed to reduce transient cool down time and thermal loss
Granted: October 21, 2008
Patent Number:
7437878
The cool down time for a multi-stage, pulse tube cryocooler is reduced by configuring at least a portion of the acoustic impedance of a selected stage, higher than the first stage, so that it surrounds the cold head of the selected stage. The surrounding acoustic impedance of the selected stage is mounted in thermally conductive connection to the warm region of the selected stage for cooling the acoustic impedance and is fabricated of a high thermal diffusivity, low thermal radiation…
Pulse tube cooler having ¼ wavelength resonator tube instead of reservoir
Granted: October 14, 2008
Patent Number:
7434409
An improved pulse tube cooler having a resonator tube connected in place of a compliance volume or reservoir. The resonator tube has a length substantially equal to an integer multiple of ¼ wavelength of an acoustic wave in the working gas within the resonator tube at its operating frequency, temperature and pressure. Preferably, the resonator tube is formed integrally with the inertance tube as a single, integral tube with a length approximately ½ of that wavelength. Also preferably,…
Photovoltaic module mounting clip with integral grounding
Granted: October 14, 2008
Patent Number:
7435134
An electrically conductive mounting/grounding clip, for use with a photovoltaic assembly of the type having an electrically conductive frame, comprises an electrically conductive body. The body has a central portion and first and second spaced-apart arms extending generally perpendicular to the central portion. Each arm has an outer portion with each outer portion having an outer end. At least one frame surface-disrupting element is at each outer end. The central portion defines a plane…
Dual mode compressor with automatic compression ratio adjustment for adapting to multiple operating conditions
Granted: August 12, 2008
Patent Number:
7409833
An apparatus and method for compressing gas refrigerant using two different compressors operated alternatively in a series or parallel mode for obtaining two different compression ratios and thereby provide efficient operation for both a relatively lower suction pressure and a relatively higher suction pressure. This system avoids an unbalanced mass flow rate when the compressors are operated in series by unloading a downstream one of the compressors. When operated in the series mode,…
Interconnection of solar cells in a solar cell module
Granted: June 24, 2008
Patent Number:
7390961
In one embodiment, a solar cell module comprises a plurality of solar cells interconnected as a solar cell array. An interconnect assembly electrically connects the backsides of two adjacent solar cells. The interconnect assembly may have an interconnect that electrically connects a contact point on a backside of a solar cell to a contact point on a backside of another solar cell. The interconnect assembly may further include an interconnect shield placed between the solar cells and the…
Metal contact structure for solar cell and method of manufacture
Granted: June 17, 2008
Patent Number:
7388147
In a solar cell having p doped regions and n doped regions alternately formed in a surface of a semiconductor wafer in offset levels through use of masking and etching techniques, metal contacts are made to the p regions and n regions by first forming a base layer contacting the p doped regions and n doped regions which functions as an antireflection layer, and then forming a barrier layer, such as titanium tungsten or chromium, and a conductive layer such as copper over the barrier…
Detection of the instantaneous position of a linearly reciprocating member using high frequency injection
Granted: May 13, 2008
Patent Number:
7372255
A piston position sensing circuit for sensing the instantaneous position of a piston of a free piston Stirling machine or a compressor mechanically connected to a reciprocating member of a linear electric motor or alternator. A source of a high frequency, alternating, electrical signal applies a high frequency signal to the winding circuit of the linear alternator or motor. A filter circuit is connected to the winding circuit and passes electrical signals at the frequency of the high…
Tracking solar collector assembly
Granted: April 1, 2008
Patent Number:
D565505
Support base for solar collector assembly
Granted: March 25, 2008
Patent Number:
D564958
Solar cell and method of manufacture
Granted: March 4, 2008
Patent Number:
7339110
A solar cell that is readily manufactured using processing techniques which are less expensive than microelectronic circuit processing. In preferred embodiments, printing techniques are utilized in selectively forming masks for use in etching of silicon oxide and diffusing dopants and in forming metal contacts to diffused regions. In a preferred embodiment, p-doped regions and n-doped regions are alternately formed in a surface of the wafer in offset levels through use of masking and…
Support base for solar collector assembly
Granted: February 19, 2008
Patent Number:
D562225
Shingle system
Granted: February 12, 2008
Patent Number:
7328534
A barrier, such as a PV module, is secured to a base by a support to create a shingle assembly with a venting region defined between the barrier and base for temperature regulation. Water resistant junctions may be formed between the bases of adjacent shingle assemblies of an array of shingle assemblies. The base may include an insulation layer underlying a water barrier. The base may also include a waterproofing element; the width and height of the barrier may be shorter than the width…
Compact micro-concentrator for photovoltaic cells
Granted: November 20, 2007
Patent Number:
7297865
A reflector array comprises a plurality of partial parabolic reflectors arranged in rows and columns with each reflector directing radiation to a receiver or from a transmitter located at the focus of the reflector. In a compact photovoltaic cell arrangement, each cell is shielded from direct radiation by the adjacent reflector. The reflectors can be formed as one unit with reflective material or with the reflecting surfaces coated with aluminum, silver, or other suitable reflecting…
Ventilated photovoltaic module frame
Granted: November 20, 2007
Patent Number:
7297866
In one embodiment, a photovoltaic frame assembly comprises a photovoltaic module and a frame having a plurality of air vents. The air vents allow air to flow into the frame and thereby cool the photovoltaic module. The frame may be installed in-line with another such frame to allow air flow between frames. The air vents may be located within a perimeter of the frame to allow for structural integrity while remaining aesthetically pleasing. The frame may include an inner lip, an outer lip,…
Temperature control for free-piston cryocooler with gas bearings
Granted: September 11, 2007
Patent Number:
7266947
A cryocooler having two operating modes so that its operating range is broadened, its gas bearing system is maintained in an operable state and it can utilize piston stroke modulation for energy efficiency. A piston stroke modulator modulates the piston stroke when the commanded piston stroke exceeds the minimum stroke and maintains the minimum stroke when the commanded stroke is less than the minimum stroke. A heater applies heater power to the thermal load when the commanded piston…
Energy efficient, inexpensive extraction of oxygen from ambient air for portable and home use
Granted: May 1, 2007
Patent Number:
7210312
Apparatus and method for separating oxygen directly from air, operating at substantially atmospheric pressure and recuperating energy used for cooling incoming air. An ambient air input leads from the atmosphere to a vessel for confining gases. A cryocooler has a cooled surface in the vessel for directly condensing oxygen from the air at substantially atmospheric pressure. The cryocooler cools the cold surface to a temperature greater than the boiling point temperature of nitrogen and…
Substrate carrier for electroplating solar cells
Granted: February 6, 2007
Patent Number:
7172184
A carrier for use in processing of a plurality of wafers or other substrates includes a support frame on which the wafers are mounted and in one embodiment at least one auxiliary frame for holding the substrates on the support frame. A plurality of clips extend from the auxiliary frame and engage the substrates in pressure engagement, and fasteners retain the auxiliary frame in position with respect to the support frame. In one embodiment two auxiliary frames can be employed for holding…
Rotor supporting structure of windmill for power generation
Granted: December 5, 2006
Patent Number:
7144214
A windmill 10 includes a frame 11 and a rotor 12 provided rotatively around the vertical shaft center. The rotor includes bosses 23, 24 located above and below, plural transversal blades 25 extending radially from the bosses, longitudinal blades 26 held by the front edges of the transversal blades 25 of both above and below bosses. The frame includes bearing 19, 20 supporting the bosses 23, 24 of the rotor rotatively around the vertical shaft center, spokes 17 provided radially…
