PatentsALERT VII

a hologram can effectively illuminate the of the solar photovoltaic cell and variably interior of a building or room with sunlight. regulate the supplied power from the solar This invention can reduce both lighting costs photovoltaic cell while comparing required and the cooling costs associated with power of the air conditioner with the supplied generating artificial light. power from the solar photovoltaic cell.

5492142 5493204

POLYCRYSTALLINE SILICON PHOTOVOLTAIC DEVICE

NEGATIVE IMPEDANCE PEAK POWER TRACKER

Sano Keiichi Osaka, JAPAN assigned to Sanyo Electric Co Ltd

Caldwell David Hermosa Beach, CA, UNITED STATES assigned to The Aerospace Corporation

A polycrystalline silicon film is prepared by forming an amorphous silicon film containing hydrogen and having an intensity ratio TA/TO of at least 0.5 of TA peak intensity to TO peak intensity in a Raman spectrum, and then heat treating the amorphous silicon film for converting the same to a polycrystalline silicon film. The polycrystalline silicon film has improved characteristics as a photoelectric conversion layer in a photovoltaic device.

5493155

ELECTRIC POWER SUPPLY SYSTEM

Okamoto Mitsuo; Kodama Hirokazu; Takebayashi Tsukasa; Minamino Kouji; Tsuyuguchi Yoshikazu; Ohmori Shigeru Yamatotakada, JAPAN assigned to Sharp Kabushiki Kaisha; The Kansai Electric Power Co Inc

This electric power supply system includes an air conditioner serving as load, a solar photovoltaic cell for supplying power to the air conditioner, and a system power control circuit and further including a commercial power source for use in combination with the solar photovoltaic cell for supplying additional power when insufficient, power is supplied from the solar photovoltaic cell to the air conditioner. In an operation state of the air conditioner, the system power control circuit operates to regulate an operating point

A peak power tracker apparatus is used for controlling the negative impedance of converter for transferring maximum power from a solar array source to a battery and load typically used in space vehicles, by capacitive differentiation sensing the solar array source voltage for sensing the peak power point at which the source voltage first begins to become unstable and collapses, and then providing a step down control signal which controls a current mode pulse width modulator to control the converter to vary the negative impedance into the solar array then reserving back to a stable point at which the tracker then provide a linear ramp signal to the modulator to control the converter to drive the source voltage again to the peak power point, so as to alternate the feedback loop and source voltage between a stable point and the peak power point so as to transfer maximum power while preventing the source voltage to pass through an unstable point for discontinuous but stable operation at peak power transfer which is independent of array performance and is adaptable to a wide range of power sources.

5494407

WIND TURBINE WITH SAVONIUS-TYPE ROTOR

Benesh Alvin Pierre, SD, 57501, UNITED STATES

VIII PatentsALERT

A Savonius rotor assembly includes two blades. Each of the blades has an outer edge and an inner edge with the outer edges of the blades lying on a circle which define the diameter of the rotor. Each of the blades has a linear portion adjacent to the inner edge and a first curved portion which is substantially an arc of a circle tangent to the linear portion and tangent to the circle defining the rotor diameter. A second curved portion is substantially coincident to the circle defining the rotor diameter.

5494832

METHOD FOR MANUFACTURING A SOLAR CELL FROM A

SUBSTRATE WAFER

Lehmann Volke; Willer Josef; Hoenlein Wolfgang Munich, GERMANY assigned to Siemens Aktiengesellschaft

Through-holes are formed in a substrate wafer by electrochemical etching, so that a perforated, self-supporting layer of n-doped, monocrystalline silicon arises. An n-doped region and a p-doped region that form a pn-junction and that both adjoin a first principal face of the self-supporting layer are produced in the self-supporting layer. A contact to the n-doped region and a contact to the p-doped region are formed on the first principal face, so that the pn-junction can be interconnected as solar cell into which the light incidence can occur via a second principal face lying opposite the first.

5495128

WIND POWERED GENERATOR

Brammeier Fred L UNITED STATES

Wilton, IA, 52778,

An electrical power generating system that uses wind power to drive hydraulic pumps or motors that in turn drive electrical generators. The system uses a plurality of squirrel-cage type fans or turbines arranged with their axes in different intersecting planes to more efficiently utilize the wind. The wind turbines are mounted on a partially enclosed supporting structure that directs the wind for the most efficient use of the turbines, and the entire unit is rotatable about a pivot support so that the unit can swing through a full circle to orient itself to the wind direction.

5533865

WIND TURBINE

Dassen Antonius G M; Hagg Franklin Vollenhove NETHERLANDS assigned to Stork Product Engineering B.V.

In order to reduce the noice nuisance caused during operation by rotor blades of a rotor of a wind turbine the rear edge of each blade is irregularly formed. In particular the saw- tooth form with a top angle smaller than about 150 degrees and preferably 10 degrees is found to produce a considerable noise reduction.