Generally, to fabricate various silicon devices, there has been widely used CZ silicon wafers which is manufactured by pulling up a silicon single crystal ingot from a silicon melt within a quartz crucible by a CZ method.In such a CZ wafer, excessive oxygen atoms eluted from the quartz crucible are interstitially caught in the silicon single crystal ingot, and the higher concentration of such interstitial oxygen atoms leads to, for example, oxygen precipitation from the silicon wafer, deterioration of a gate oxide film in a semiconductor integrated circuit, and an increase of a p-n junction leakage current. As such, upon forming semiconductor integrated circuits on the principal plane of the CZ wafer, there are reduced oxygen precipitations near the surface of the wafer by lowering the oxygen concentration of the silicon wafer supplier .

To this end, in the first aspect of the present invention, a silicon wafer is free of vacancy agglomerates and interstitial agglomerates, wherein the silicon wafer has a defect density of an oxide film of 0.1 piece/cm  2  or less, when the oxide film having a thickness of 5 to 25 nm is formed on the surface of the wafer and a DC voltage of 10 MV/cm is applied via the oxide film for 100 seconds, and wherein the silicon wafer manufacturer has an in-plane dispersion of 20% or less of a p-n junction leakage current in a p-n junction area of 1 mm  2  or more of a p-n junction portion when the p-n junction portions are formed on the surface of the wafer.

 

source:livejournal chinasun-solar

The generation of electricity from photovoltaic cells has been a reality for many years, but it does not yet contribute a significant fraction of overall electricity generation. A reason for this is that electricity generated by photovoltaic cells is more expensive than conventionally generated electricity, mainly because the cost of individual photovoltaic cells is still high. There are two approaches that can be used to reduce costs. One option is to manufacture the cells from cheaper materials, but this generally leads to a lower conversion efficiency. Alternatively, cell efficiency may be increased. High efficiency cells can be used in solar concentrators where light from the sun is collected over a large area and concentrated onto a smaller area photovoltaic cell , or in thermophotovoltaic systems where the cells are illuminated by high intensity light generated from a hot source such is as created by the combustion of fuel.

Photovoltaic cells work on the atomic level, operating by the physical principle of the photoelectric effect, which the semiconductors perform. Each photon, or particle of light, has certain energy, which the PV cell absorbs and converts to electricity.For every photon of light that strikes the semiconductor of a PV cell , one electron is released. When the semiconductor is attached to a circuit, the release of electrons forms an electric current in direct current (DC) form. The silicon material of the cell absorbs the photon and releases the electron to the attached circuit.

Photovoltaic cells are used in solar panels, to convert light energy to electricity when other sources of electricity are not readily available. Satellites, space shuttles and the International Space Station all utilize photovoltaic cells in solar panels.Solar energy is popular because it is a form of renewable energy and does not rely on fossil fuels, which makes it more environmentally friendly. Presently, it is still more expensive than other common sources of electricity, but the semiconducting materials are readily available and the course of technological development has made it gradually more cost-effective. Solar-powered calculators and other common devices use photovoltaic cells supplier today.

 

source:blogigo chinasun-solar

A photovoltaic system includes a photovoltaic device that includes lower photovoltaic cells fabricated from semiconductor material having a first bandgap, and having first electrical contacts for extraction of current from the lower cell; an electrically insulating layer monolithically fabricated on the lower photovoltaic cell; and an upper photovoltaic cell monolithically fabricated on the electrically insulating layer from semiconductor material having a second bandgap larger than the first bandgap, and having second electrical contacts for extraction of current from the upper cell.

The photovoltaic system also includes one or more first photon sources operable to supply photons to the photovoltaic device, the photons having wavelengths in a first wavelength range associated primarily with the first bandgap. The photovoltaic system further includes one or more second photon sources operable to supply photons to the photovoltaic device, the photons having wavelengths in a second wavelength range primarily associated with the second bandgap.

A photovoltaic cell converts light into electricity. To perform this function, cells use special substances that are treated to be especially effective in transferring light energy to electrical current. The substances are particularly stable, which allows them to safely and effectively transfer the energy from light into electricity. These substances are called semiconductors.Photovoltaic cells use special materials known as semiconductors to absorb the energy of light and convert it into electricity. The most common substance used in PV cells is silicon. Semiconductors used in PV cells must be stable enough to absorb the energy of the light without reflecting it or converting it to heat. The silicon in semiconductors is passed through a special process of polarization, which makes one end positively charged and one end negatively charged. When a circuit is attached to connect the ends to each other, the current can be gathered from the energy the semiconductor collects.

 

source:blogigo chinasun-solar 

To this end, in the first aspect of the present invention, a silicon wafer is free of vacancy agglomerates and interstitial agglomerates, wherein the silicon wafer has a defect density of an oxide film of 0.1 piece/cm 2 or less, when the oxide film having a thickness of 5 to 25 nm is formed on the surface of the wafer and a DC voltage of 10 MV/cm is applied via the oxide film for 100 seconds, and wherein the silicon wafer manufacturer has an in-plane dispersion of 20% or less of a p-n junction leakage current in a p-n junction area of 1 mm 2 or more of a p-n junction portion when the p-n junction portions are formed on the surface of the wafer.

Further, in the second aspect of the present invention, a silicon wafer is free of vacancy agglomerates and interstitial agglomerates, wherein the silicon wafer china has a defect density of an oxide film of 0.1 piece/cm 2 or less, when the oxide film having a thickness of 5 to 25 nm is formed on the surface of the wafer and a DC voltage of 10 MV/cm is applied via the oxide film for 100 seconds, and wherein the silicon wafer has in-plane dispersions of 20% or less of both of: a recombination lifetime by a photo conductive decay method; and a generation lifetime measured by a MOS C-t method by forming a MOS capacitor.

The present silicon wafers according to the first and second aspects satisfy these characteristics, to thereby guarantee characteristics of various semiconductor devices with higher reliability. Further, the absence of an epitaxial layer leads to the retention of the gettering ability.

 

Source:news chinasun-solar

The wafer is then put through further processing to ensure its purity. It is inserted into an acid mixture that removes any abrasion caused by previous processes, then heated to a specific temperature to remove any impurities that might have been accidentally created when the crystal was formed. The wafer is then polished using highly sensitive equipment and cleaned in a solution of purified water and light cleansing agents.

The silicon wafers may be completed, but that does not mean it passed through all of its production processes undamaged. To make sure the wafer is pure enough and strong enough to be used for circuit boards, it is inspected to make sure that there are no flaws, that the flatness of the wafer is sufficient and that it has the proper resistance qualities.

It is therefore an object of the present invention to provide a silicon wafer capable of achieving a higher performance, higher yield and uniformity of characteristics of semiconductor devices comparable to a wafer provided with a pure epitaxial layer, without deteriorating the gettering ability of the silicon wafer.

 

Source:news chinasun-solar

The present invention provides silicon wafers free of vacancy agglomerates and interstitial agglomerate; wherein the silicon wafer has a defect density of an oxide film of 0.1 piece/cm2 or less, when the oxide film having a thickness of 5 to 25 nm is formed on the surface of the wafer and a DC voltage of 10 MV/cm is applied via the oxide film for 100 seconds, and wherein the silicon wafer has an in-plane dispersion of 20% or less of a p-n junction leakage current in a p-n junction area of 1 mm2 or more of a p-n junction portion when the p-n junction portion is formed on the surface of the wafer. The present silicon wafer is capable of achieving a higher performance, higher yield and uniformity of characteristics of semiconductor devices comparable to a wafer provided with a pure epitaxial layer, without deteriorating the gettering ability of the silicon wafer.

Silicon is a naturally occurring substance that can be mined from the earth in mineral form, but for the precise circuit board chips that silicon wafers are used to make, silicon wafer manufacturers need a purified crystalline form. They can create these pure crystals by melting down the mined poly-crystal silicon in a vacuum. The melted silicon is then carefully reassembled into crystalline ingot, the size and purity of which is determined by what kind of wafers the ingot will be used to create.Not all silicon is made pure, though. Some silicon wafers, such as those used in photovoltaic cells, are combined with other substances to give them different conduction qualities. There are many different variants to these hybrid silicon wafers, and the process to create these hybrids may differ depending on the manufacturer and the material's purpose.

A silicon wafer free of vacancy agglomerates and interstitial agglomerates, wherein said china silicon wafer has a defect density of an oxide film of 0.1 piece/cm2 or less, when the oxide film having a thickness of 5 to 25 nm is formed on the surface of the wafer and a DC voltage of 10 MV/cm is applied via the oxide film for 100 seconds, and wherein said silicon wafer has an in-plane dispersion of 20% or less of a p-n junction leakage current in a p-n junction area of 1 mm2 or more of a p-n junction portion when said p-n junction portion is formed on the surface of said wafer.

Next, the ingot is then ground into a cylinder with a very specific length and diameter. A mark is usually added to the cylinder to show which way the crystalline structure is oriented, knowledge vital when the cylinder is being prepared for slicing. In the slicing phase, a machine equipped with a moving diamond blade cuts through the cylinder, dividing it into thin wafers.

While the diamond-bladed machine is very accurate, it is not accurate enough to create the precise silicon wafers supplier that manufacturers require, so the wafer disks are then sent on to be ground down to the proper size (depending on their use) and rounded into a more perfect circular shape. The surface of the wafers is then lapped by machines that can pare the size of the wafers down by thousandths of an inch, based on how thin they need to be.

 

Source:news chinasun-solar

As a wafer with a device such as a semiconductor integrated circuit, silicon wafers by the Czochralski method (CZ method) is mainly used to produce grown. If the crystal defects in the monocrystalline silicon wafer failure pattern occurs when a semiconductor device is produced. Above all, the breadth of the product structure highly integrated in recent years, a fine of 0.3 meters or less. Thus, even small defects in crystals up to 0.1 m as can abnormalities, such as the breakdown of the device and can significantly reduce the performance and features of the device. Therefore, the size and density of crystalline defects in monocrystalline silicon wafers are as low as possible.

Recently it was reported that the crystal defects are the defects is known to develop in adults in the crystal growing Incorporated in the silicon crystal by the CZ method. The main reason for the formation of crystal defects is considered as has a group of nuclear bodies in the production of single crystal or a precipitate of oxide, which is a cluster of atoms of oxygen entering a quartz crucible. When these crystalline defects are present in the portion of the surface on which the device is manufactured, reached harmful defects degrade device properties. It is therefore suitable for producing a silicon wafer with the Kill Zone (DZ) with sufficient depth to the surface and reduces the errors in the glass, for example.

 

 

 

It is known that the density is raised to the above-mentioned problem can be reduced by treatment at high temperature for a silicon wafer in a vacuum. But the adoption of this method for a conventional silicon wafers , which are grown by CZ method, it is a problem that some defects are always present in an internal region of the surface of the wafer about 0.3 m deep and more, and a bare zone depth is shallow. Accordingly, a conventional wafer with little flexibility in the manufacture of a device.
 To solve the above problem, the present invention on a silicon wafer through the conversion of monocrystalline silicon ingots by the Czochralski technique, in which defects in silicon wafers, empty street, and / or empty defects within the plate shaped plaque. As described above, when a single crystal silicon ingot is by CZ method, defects in the grown ingot in the form of stem and formed / or the shape of plates. Consequently, the relative share of the region the size of the defects is higher than that of the octahedral defects, and if the heat treatment is conducted, deficiencies are reduced to a deeper region.
In addition, the shape of the product bar defects, Knowledge and / or the form of plates, as in this sense is not that, as octahedral defects as clear spherical or confinement in a conventional plate.  monocrystalline silicon wafers are one of the main types of wafers for the manufacture of silicon solar cells, the building block of solar panels.
Silicon wafers, monocrystalline wafers, solar cells convert sunlight into electricity.A enable complex process, the production of monocrystalline silicon wafers, which represents the growth of monocrystalline silicon, reports the Florida Solar Energy Center. Extremely thin slices of glass cut and then doped with chemicals to treat its ability to convert sunlight into electricity increase.

monocrystalline solar cells with the most effective are to be home-based solar cells used frequently, Sun Power free. to convert an average 15-18 percent monocrystalline panels to more efficiency.In are to increase efficiency, monocrystalline solar cells based on smaller, so that they are installed in a variety of parameters. Creates the economies more energy efficient than costs.Due the manufacturing process of complex monocrystalline wafers and solar cells are more expensive than mono or polycrystalline thin-film solar cells. Like all solar technologies, monocrystalline wafer is doing his best in environments with high sunlight.SolarPowerFast. com reports that the windows should have a monocrystalline average life expectancy of at least 25 years consume use, provided that the panels could be injured.

 

source:GEMEI news|silicon wafers

FIG. 1 is a vertical sectional view showing a clearance lamp to which a first embodiment of the present invention is applied;
FIG. 2 is a partly cut away perspective view of a lamp body of the clearance lamp shown in FIG. 1;
FIGS. 3A, 3B, 3C and 3D are views for explaining steps of unitarily attaching a gasket to a seal leg;
FIG. 4 is a vertical sectional view showing a clearance lamp to which a second embodiment of the present invention is applied;
FIG. 5 is a sectional view showing a conventional automotive leds ; and
FIG. 6 is a sectional view of an essential part of another conventional automotive lamp.

FIG. 5 is a vertical sectional view showing a conventional automotive lamp of the type as disclosed, for example, in Unexamined Japanese Patent Publication No. Hei. 3-15748. The conventional automotive lamp shown in FIG. 5 includes a lamp body 1 which is formed on a back wall thereof with a seal leg 2 projecting therefrom for surrounding a bulb insertion hole 2 and a gasket 8 disposed between the seal leg 2 and an automobile body panel 6. Both a front and a rear side of the gasket 8 have a respective high adhesive surface so that the gasket 8 sticks both to the seal leg 2 and the automobile body panel 6. In the figure, reference numeral 3 designates a front lens and a reference numeral 4 designates lamp bulb.

FIG. 6 is a sectional view of an essential part of another conventional automotive lamps . As shown in FIG. 6, a gasket 8A is formed like an endless web a cross section of which is U-shaped. An adhesive agent is applied, if desirable, to a tip end of the seal leg 2 so that the gasket 8A sticks to the seal leg 2.

According to the conventional gasket 8 as described above and shown in FIG. 5, however, since the gasket 8 is formed by cutting out a seat-like material to have a frame-shape to fit to the configuration of the tip end of the seal leg 2, the yield rate of the material is very unsatisfactory which raises manufacturing cost.

Further, the high adhesive surfaces of the gasket 8 shown in FIG. 5 are actually made from a double-sided adhesive tape. More specifically, the double-sided adhesive tape with a peel-off sheet on each side is attached to each the front and rear surfaces of the gasket 8. Accordingly, during assembly of the conventional automotive lamp, when the lamp is coupled to the automobile body, the gasket 8 is disposed between the seal leg 2 and the automobile body panel 6, the peel-off sheet on one side of the gasket 8 is peeled off to expose the adhesive surface, and then the adhesive surface is pressed against the seal leg 2 so that the gasket 8 sticks integrally to the seal leg 2. Next, the peel-off sheet of the other side of the gasket 8 is peeled off, and then the lamp is coupled to the automobile body, so that the adhesive surface of the gasket 8 sticks to the automobile body panel 6. Thus, the conventional automotive lamps manufacturer requires complicated steps during assembly, which steps take a relatively long time. That is a problem because it raises the manufacturing cost.

On the other hand, according to the secondary conventional gasket 8A shown in FIG. 6, the gasket 8A is formed by the injection molding operation, and the cost for the mold die apparatus or the like is very high. In addition, the gasket 8A must be attached to the seal leg 2 prior to coupling the lamp to the automobile body. This is intricate. Further, in a case where no adhesive agent is applied to the tip end of the seal leg 2, the gasket 8A may sometimes drop off the seal leg 2.

As described above, according to the automotive lamp of the present invention, a gasket can be molded integrally with a seal leg merely by inserting the seal leg into a foamed gasket material injected into a molding groove. Therefore, the present invention greatly improves the yield rate of the gasket material, and reduces the cost for the gasket, which in turn reduces, the cost for the lamp.

Further, because the gasket is securely integrated with the seal leg, and because the gasket automatically becomes press-fitted between the seal leg and the automobile body panel at the same time the lamp is coupled to the automobile body, the workability is much improved.

The gasket tightly contacts to the seal leg and the automobile body panel when the automotive lamp china is coupled to the automobile body. Therefore, the sufficient sealability of the gasket can be maintained compared with the conventional gasket.

Incidentally, when the gasket is molded integrally with the tip end part of the seal leg, some of the molding steps can be readily automated. If some steps are automated, mass-production of the lamps can be achieved while excessively reducing the manual works.

In addition, if the seal leg is subjected to the surface active treatment, the gasket would hardly detach from the seal leg because of the high adhesibility of the foamed gasket to the seal leg. As a result, easy treatment of the lamp with which the gasket is integrated, improved operation for coupling the lamp to the automobile body, and good workability when the gasket is fitted, can be accomplished.

It should be understood that the form of the invention herein shown and described is to be taken as a preferred example of the invention and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

 

 

from:freepatentsonline

The general purpose of the present invention, which will be discussed subsequently in greater detail, is to provide a solar hot water heater that has all of the advantages of the prior art solar hot water heaters and none of the disadvantages. To attain this, the present invention provides for an insulated box in which one or more water storage tanks may be positioned, such insulated box having a lid portion which may be selectively opened or closed to expose the water storage tanks contained within the box. A heat actuated control unit is provided on an exterior surface of the box, such control unit having a single pole double throw thermostat associated therewith, whereby an electric winch gear motor may be selectively operated to either open or close the lid of the box. Inasmuch as the interior and lid portions of the box are coated with a highly reflective material, at such times that the lid is in an open position, the sun's rays may be caused to reflect off of the reflective surfaces so as to effectively heat the water contained within the one or more water storage tanks.

FIG. 1 is a perspective view of the solar hot water heater forming the present invention.
FIG. 2 is another perspective view illustrating a plurality of the solar water heater forming the present invention being in position to operably receive energy from the sun.
FIG. 3 is a top plan view of the present invention with the lid associated therewith in an open position.
FIG. 4 is a transverse plan view, partly in cross section, illustrating the constructional details of the present invention, as viewed along line 4--4 of FIG. 3.
FIG. 5 is a top plan view of the heat actuated control unit forming a part of the present invention and having its cover portion removed.
FIG. 6 is a transverse cross-sectional view of the heat actuated control unit taken along the line 6--6 of FIG. 5.
FIG. 7 is a top cross-sectional view of the heat actuated control unit taken along the line 7--7 of FIG. 6.
FIG. 8 is an enlarged detail view, partly in cross section, illustrating the use of a drain line proximate to a topmost edge of the box forming a part of the present invention.

With reference now to the drawings and in particular to FIG. 1 thereof, a solar hot water heater embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described. Specifically, it can be seen that the solar panel manufacturer 10 includes an insulated box 12 having a lid 14 hingedly attached thereto, and further having a heat actuated control unit 16 operably mounted on a front wall 18 forming a part thereof. Additionally, a support beam 20 is positioned behind the box 12, such support beam having an electric winch gear motor 22 operably attached to a topmost portion thereof and further having an adjustable lid stop arm 24 fixedly secured proximate to the electric winch gear motor. As illustrated, the electric winch gear motor 22 is operably attached to the lid 14 by means of a cable 26 fixedly secured to the lid by conventional attachment means, such as a screw 28, or the like, and further being rotatably positioned around a gear motor pulley 30 operably associated with the electric winch gear motor 22.

While the solar hot water heater 10 forming the present invention has been illustrated in FIG. 1 with its lid 14 in a closed position, FIG. 2 illustrates a plurality of the solar hot water heaters 10 forming the present invention, each of which has its lid 14 in an open position whereby the sun's rays may be directed into an interior portion thereof. Specifically, it can be seen that a lid 14 is normally hingedly attached to a box 12 through the use of a plurality of conventional hinges 38 connected between the respective lid and box. Additionally, FIG. 2 serves to illustrate the fact that a winding of the cable 26 upon the gear motor pulley 30 will effect the desired lifting of a lid 14 into an open position. Further clearly illustrated in FIG. 2 is the fact that the lid stop 24 is adjustably mounted to the support beam 20 through the use of a longitudinally extending slot 40 positioned within the lid stop 24, such slot serving to facilitate the attachment of the lid stop to the beam through the fixed securing of one or more screws 42 through the slot and into the structure of the beam per se. Further, it can be seen that the lid 14 is limited in its movement into an open position by coming into contact with an extending end of the lid stop 24, whereby the switch 34 is brought into an abutting contact with the lid. In this regard, the switch 34 serves to cut off the electric power to the electric winch gear motor 22 so as to cause a cessation in the winding of the cable 26 about the gear motor pulley 30, thereby to prevent any further opening of the lid. Also partially evident in FIG. 2 is the fact that the respective solar hot water heaters 10 have hollow interior portions which are substantially sealed from an external environment through the use of sheets of glass 44, or some similar transparent material. If desired, a cross extending support member 46 may be utilized to give added support to the panes of glass 44 positioned over a topmost portion of the box 12, while a switch 48 may be operably positioned on an edge portion of the box, such switch serving to turn off the electric power to the electric winch gear motor 22 once the lid 14 has moved into a closed position.

With respect to the operation of the solar hot water heater 10, it can be appreciated that the same may be fluidly connected within an existing water supply system associated with a dwelling or the like and further should be positioned in a location having maximum exposure to the sun's rays. With particular reference to FIG. 1 of the drawings, wherein the solar hot water heater 10 is illustrated with its lid 14 in a closed position, it can be seen that an exposure of solar panel manufacturer radiation will cause a rise in temperature to be experienced by the heat actuated control unit 16. This rise in temperature, of course, causes the single pole double throw thermostatic switch 32 to activate the electric winch gear motor 22 so as to cause the cable 26 to lift the lid 14 into an open position. With reference to FIG. 4 of the drawings, it will be noted that the lid 14 will open until such time as it comes into contact with the switch 34 as positioned on the end of the adjustable lid stop 24, such switch serving to turn off the electric winch gear motor 22.

 

 

source:freepatentsonline

A solar hot water heater includes an insulated box having one or more hot water storage tanks contained inside and further having a lid which may be opened to permit solar radiation to heat a supply of water contained within the one or more hot water storage tanks. A heat-actuated control unit is mounted on an external portion of the box, such control unit having a single pole double throw thermostat which selectively activates an electric winch gear motor to either open or close the box lid. The control unit operates to open the lid to a predetermined position when exposed to the sun's rays, and further operates to immediately close the lid in response to any sudden drop in temperature, such as might occur during a rainstorm, clouds moving in front of the sun, or the like.

Here is a way to get hot water for free using energy from the sun. Don't pay for a pricy unit when you can make one for yourself. The uses for a portable solar hot water heaters are endless, scale up and you have free hot water in your home.
Take your copper tubing and roll it into a coil. The copper piping can't overlap itself in any way. Any easy way to d this is cap off the ends with it full of water. This insures and even bend without kinks. Leave two tales on the piping like the picture below.

The present invention relates generally to solar hot water heaters and more particularly pertains to a new and improved solar hot water heaer that will selectively expose a supply of water to the sun's rays in response to a sensed temperature and which will further insulate the water supply from heat loss during such periods of time that a temperature drop is being experienced.
It is well known that the sun's energy can be harnessed through a variety of techniques and for many different purposes. In this respect, the use of the sun's energy to heat hot water is a developing art, and there is a continuing need for new and improved devices which both efficiently and reliably capture the energy of the sun. Typically, these devices have proven to be quite unwieldy and very expensive to install, as well as being very inefficient due to excessive heat loss experienced when a transfer of solar heat from a collector to a removed storage chamber is effected. In this regard, prior art solar water heater heating systems have not been capable of being easily installed proximate to or in existing building structures and have not been devised to cooperate as an auxiliary heating unit with the conventional water heating systems commonly found in building structures.

Make your box big enough for your copper coil to fit into this can be done out of scrap 2x4's ripped on center or any scrap lumber you have cut to fit. Two holes need to be drilled on the side of your box allowing for the copper tales to exit the box.
Fit a scrap piece of plywood to the back of your box and insert the piece of polystyrene backer board. Paint the box using flat black spray paint.
Using Plexiglas, lexan glass, or old picture frame glass and a glass cutter cut to fit the top of the box. You can later assemble this glass to the top with clear silicone.

With respect to the particular structural arrangement of a typical solar hot water heating system, reference is made to U.S. Pat. No. 4,059,226, issued to Atkinson on Nov. 22, 1977, wherein there is disclosed a heat collector and storage chamber which utilizes a solar panel manufacturer protected by a door positionable over the solar collector elements associated therewith. In this respect, the Atkinson device refers to the door as being electrically operated to open and close the same and further, it is noted therein that the door may have reflective surfaces and be positionable at a desired angle whereby the sun's rays may be reflected onto the solar collecting elements. However, while the concept disclosed in the Atkinson patent is particularly interesting, the means and manner of so positioning the door are not disclosed.

As such, it can be appreciated that there exists a continuing need for new and improved solar hot water heating devices, such as the type disclosed in the patent to Atkinson, and in this regard, it would be particularly useful to have a solar hot water heating apparatus which would automatically expose a supply of water to be heated to the sun's rays when available and which would further protectively insulate the water supply in the event of a temperature drop, such as might occur during a sudden rainstorm, the sun being shaded by clouds, etc. In this respect, the present invention substantially fulfills this need.

Using a camp stove heat the copper pipe until it begins to carbon black. Carbon blacking the pipe is more effective than spray painting the pipe, it allows more heat to be absorbed.
At this point you can use your solar water heater . If you wish cut 4 equal pieces of steel/tin flashing. The pieces should be the same size as the top of your box. drill holes in the flashing and pop rivet brass hinges to them. Screw the hinges into the sides of your collector box.

Before choosing a hot water heater for your home or business there are three energy types to consider: electric, gas and solar. A gas water heater will require natural gas or propane. If the building is not hooked up to natural gas, a propane tank will need to be installed on the property in order to operate a gas heater. If you would like to consider a solar water heater , you will need to determine if there is sufficient sunshine and room for the equipment prior to installation.

1.Confirm the heat-generating supply you want to use is available. An electric water heater usually requires a 220-volt dedicated service. Do not choose a gas heater if gas or propane is not available.

2.Determine what size water heater you require. An average size residential home will require a 50 gallon water heater to handle normal hot water needs. A solar water heater is usually a larger unit, because it needs to circulate more through the solar panels.

3.Check the area or space where the water heater will be located. Make sure there is enough height and width space. Water heaters come in different heights. They are typically between 4 and 5 feet high. The shorter water heater is larger in diameter in order to accommodate the same number of gallons.

4.Consider the instant, on-demand water heaters. These typically do not have a tank, and they heat water instantly, as needed. They tend to be more expensive, yet save in energy usage.

5.Make sure the inlet and outlet water line fittings are compatible with the water lines feeding the water heater and returning the water to the home.

Solar water heaters comprising: a water tank for holding water; a solar heating compartment for heating water having a top surface, a bottom surface, and at least one side surface wherein the top surface and side surface are constructed from transparent materials, said heating compartment further containing water tubing in communication with water in the water tank, a hot water outlet extending fully through the side surface of the heating compartment whereby water which has been heated within the water tubing may be released from the heating compartment, and at least one parabolic reflector positioned to reflect incident sunlight which has entered the heating compartment upon the water tubing for absorption thereupon, said heating compartment being sealed from the atmosphere to prevent the escape of heat into the atmosphere; and an air pump in communication with the water tubing within the solar heating compartment which may be selectively activated to create a partial vacuum within the water tubing, thereby causing water to continuously flow from the water tank through the water tubing and out from the hot water outlet by the siphoning effect.

The solar hot water heater as recited in claim 1, wherein the solar heating compartment comprises a plurality of parabolic reflectors and wherein the water tubing is convoluted, thereby resulting in a larger surface area of water tubing upon which light reflected from the parabolic reflectors may be absorbed.

The solar water heater as recited in claim 2, wherein both the water tank and the solar heating compartment are substantially cylindrical, both having a flat, circular top surface, a flat, circular bottom surface and a curved side surface, wherein the bottom surface of the heating compartment substantially overlaps the top surface of the water tank.
The solar water heater as recited in claim 3, wherein the bottom surface of the heating compartment is constructed from an insulator material, for effectively insulating against heat loss from the water tank to the atmosphere.
The solar water heater as recited in claim 4, wherein the water tubing within the solar panel manufacturer which is of wider diameter and tubing which is of narrower diameter, wherein the tubing of wider diameter comprises a water reservoir, which is substantially centrally located at a position at a focal point of the parabola at which maximal absorption of light reflected upon it by the parabolic reflector will occur.
The solar water heater as recited in claim 5, wherein the parabolic reflector is constructed from highly reflective stainless steel.

A method of using a solar water heater for heating water by a user, said solar water heater comprising a water tank for holding water, and a solar heating compartment for heating water having a top surface, a bottom surface, and at least one side surface wherein the top surface and side surface are constructed from transparent materials, said heating compartment further containing water tubing having a surface and in communication with water in the water tank, a hot water outlet whereby water which has been heated within the water tubing may be released from the heating compartment, and at least one parabolic reflector positioned to reflect incident sunlight which has entered the heating compartment upon the surface of the water tubing for absorption thereupon,
 said solar panels further comprising an air pump in communication with the water tubing within the solar heating compartment which may be selectively activated to create a partial vacuum within the water tubing, thereby causing water to continuously flow from the water tank through the water tubing and out from the hot water outlet by the siphoning effect, comprising the steps of: a) positioning the solar water heater at a location where sunlight directly shines upon the at least one parabolic reflector in the solar heating compartment; b) filling the water tank by adding water via the water tank inlet connection; c) filling the water tubing with water by selectively activating the air pump until water fills the water tubing; d) heating the water in the water tubing by absorption by the surface of the water tubing of reflected sunlight from the parabolic reflector; e) opening the hot water outlet of the solar heating compartment, and thereby releasing hot water; and f) emptying the water from the water tank when the solar water heater is no longer being deployed by opening the water tank drain.

The method of using solar water heaters as recited in claim 7, wherein the water tubing within the solar heating compartment comprises tubing which is of wider diameter and tubing which is of narrower diameter, wherein the tubing of wider diameter comprises a water reservoir, which is substantially centrally located at a position at which maximal absorption of light reflected upon it by the parabolic reflector will occur, and wherein the step of heating the water in the water tubing comprises heating the water within the water reservoir.

The idea of heating water with the power of the sun is as old as … the Earth! But capturing that energy to efficiently heat water for domestic use is a more recent innovation. You can purchase and install manufactured solar hot water systems or build one yourself. Beginning in 2010, all new-house construction in Hawaii will be required to have solar water heaters.

Rather than a whole-house system, you can erect a simple outdoor, solar-heated shower.

MOTHER EARTH NEWS readers have been inventing ways to produce solar water heater for decades. Have you built a solar water heater? If so, in the comments section below, tell us about it and how well it performed.
The state of Hawaii just passed a new law requiring all new homes to have solar water heaters installed starting in 2010. The bill, signed by Republican Governor Linda Lingle, will not allow building permits to be issued for homes that do not have solar water heaters.

Hawaii is the first state to require such a law and Hawaiian Electric Co. estimates that about 85, 000 households, or roughly 20 percent, already have solar water heaters installed. The law is a big move for a state that relies heavily on imported fossil fuels for 90 percent of its supply.

A traditional water heater is the most electricity-consuming appliance in a home and it accounts for about 40 percent of all home energy use, according to an article from the Associated Press. Solar water heaters reduce energy use by about 30-35 percent and with those savings the initial expense of the water heater can be paid off in three to four years, says MSNBC. Solar water heaters cost about $7000 on top of already sky-high Hawaiian mortgage costs, but supporters are confident that the benefits to the environment and foreign energy independence will be worth it.

Similar to a wind-powered town in Missouri, Hawaii’s new law takes the initiative in having its citizens partake in renewable energy practices, rather than just giving them the option. In January, Lingle announced the Hawaii Clean Energy Initiative, which seeks to have at least 70 percent of Hawaii’s energy come from renewable sources by 2030.

In the year of 2007, China solar water heater market grew at a pace of around 30%, with the annual output reaching 23.4 million square meters. Up till now, China’s total Solar Hot Water Heater have covered approximately 108 million square meters. In 2007, China’s total sales of solar water heater stood at around CNY32 billion. China had more than twenty solar water heater producers with each having an annual output value exceed CNY100 million in the year, including Shandong Huangming Solar Energy Group Co., Ltd, Shandong Linuo Group Co. Ltd., Jiangsu Sunrain New Energy Group, Shandong Sangle Solar Energy Co., Ltd, Beijing Tsinghua Solar Co., Ltd., Jiangsu Huayang Solar Water Heater Co., Ltd, Jiangsu Huaiyin Huihuang Solar Energy Co., Ltd, Jiangsu Sunshore Solar Energy Industry Co., Ltd and Tianpu Solar Energy Co., Ltd.

   Let’s look at the global market. In the period 2005 to 2006, the total capacity of solar-powered water heater/ heating system, not including solar-powered heating system in open-air swimming pools, rose 19.3% year on year to 128 GWth from 88GWth. It is estimated that in 2007, the capacity of solar water heater/heating system would be 128 GWth, up 15.7% year on year. When the discarded or eliminated heating systems were included, the year of 2006 would have a total increment of 18GWth in capacity globally. Meanwhile, China’s addition of newly installed capacity rose 75.3%, ranking the first in the world in terms of newly installed capacity. China’s export of solar water heaters , boosted by international market, also had a rise. In 2007, China’s export value of solar water heater rose 28% year on year to US$65 million. The companies with big export value included Jiangsu Sunrain New Energy Group, Shandong Linuo Solar Energy Group and Beijing Tsinghua Solar Co., Ltd. Jiangsu Sunrain New Energy Group has set up companies in South Korea and Spain.

     From the perspective of some Chinese solar water heater producers’ performance in 2008, sales volume of Jiangsu Sunshore Solar Energy Industry Co. in the first quarter jumped 76% year on year, while sales revenue of Shandong Sangle Solar Energy Co., Ltd. Increased by 56% and skyrocketed in April, 2.58 times the figure in the same period of a year ago. Jiangsu Sunrain New Energy Group’s sales revenue in March of 2008 grew 66% year on year. The growth of market sales was, to a great extent, attributed to more efforts made in market promotion. The rising cost of raw materials has put pressure on solar water heater producers to raise prices of their products, already the most expensive one among the three types of water heaters. However, energy prices still have room to rise in the future, which will bring more potential consumption demands to solar water heater . Although China still has such problems that it doesn’t have the policies like some other countries do for compulsory installation of solar products or subsidy granting, its solar energy producers are not equal in strength and its consumer-satisfaction degree is still not high, China’s solar water heater as the best applied product in renewable energy market in China will still have a bright future. Industry competition will intensify, but China’s solar water heater industry will become healthier after another round of reshuffle in the future.

 

 

from:chinafanyi

A solar updraft tower (also known as a solar chimney or solar tower) consists of a large greenhouse that funnels into a central tower. As sunlight shines on the greenhouse, the air inside is heated, and expands. The expanding air flows toward the central tower, where a turbine converts the air flow into electricity. A 50 kW prototype was constructed in Ciudad Real, Spain and operated for eight years before decommissioning in 1989.

Thermoelectric, or "thermovoltaic" devices convert a temperature difference between dissimilar materials into an electric current. First proposed as a method to store solar energy by solar pioneer Mouchout in the 1800s, thermoelectrics reemerged in the Soviet Union during the 1930s. Under the direction of Soviet scientist Abram Ioffe a concentrating system was used to thermoelectrically generate power for a 1 hp engine. Thermogenerators were later used in the US space program as an energy conversion technology for powering deep space missions such as Cassini, Galileo and Viking. Research in this area is focused on raising the efficiency of these devices from 7–8% to 15–20%.

Beginning with the surge in coal use which accompanied the Industrial Revolution, energy consumption has steadily transitioned from wood and biomass to fossil fuels. The early development of solar technologies starting in the 1860s was driven by an expectation that coal would soon become scarce. However development of solar technologies stagnated in the early 20th century in the face of the increasing availability, economy, and utility of coal and petroleum.

The 1973 oil embargo and 1979 energy crisis caused a reorganization of energy policies around the world and brought renewed attention to developing solar technologies. Deployment strategies focused on incentive programs such as the Federal Photovoltaic Utilization Program in the US and the Sunshine Program in Japan. Other efforts included the formation of research facilities in the US (SERI, now NREL), Japan (NEDO), and Germany (Fraunhofer Institute for Solar Energy Systems ISE).

Between 1970 and 1983 photovoltaic installations grew rapidly, but falling oil prices in the early 1980s moderated the growth of PV from 1984 to 1996. Photovoltaic production growth has averaged 40% per year since 2000 and installed capacity reached 10.6 GW at the end of 2007, and 14.73 GW in 2008. Since 2006 it has been economical for investors to install photovoltaics for free in return for a long term power purchase agreement. 50% of commercial systems were installed in this manner in 2007 and it is expected that 90% will by 2009. Nellis Air Force Base is receiving photoelectric power for about 2.2 ¢/kWh and grid power for 9 ¢/kWh.

Commercial concentrating solar water heater plants were first developed in the 1980s. CSP plants such as SEGS project in the United States have a levelized energy cost (LEC) of 12–14 ¢/kWh. The 11 MW PS10 power tower in Spain, completed in late 2005, is Europe's first commercial CSP system, and a total capacity of 300 MW is expected to be installed in the same area by 2013.

In August 2009, First Solar announced plans to build a 2 GW photovoltaic system in Ordos City, Inner Mongolia, China in four phases consisting of 30 MW in 2010, 970 MW in 2014, and another 1000 MW by 2019. As of June 9, 2009, there is a new solar thermal power station being built in the Banaskantha district in North Gujarat. Once completed, it will be the world's largest.

 

World's largest concentrating solar thermal power stations

Capacity (MW)	Technology type	Name	Country	Location	Notes
354	parabolic trough	Solar Energy Generating Systems	USA	Mojave desert California	Collection of 9 units
75	parabolic trough[60]	Martin Next Generation Solar Energy Center [61]	USA	near Indiantown, Florida	Expected Late 2010
64	parabolic trough	Nevada Solar One	USA	Las Vegas, Nevada
50	parabolic trough	Andasol 1	Spain	Granada	Completed November 2008
20	solar power tower	PS20 solar power tower	Spain	Seville	Completed April 2009
11	solar power tower	PS10 solar power tower	Spain	Seville	Europe's first commercial solar tower

 

Solar panel manufacturer in recent years have also begun to expand into residential areas, with governments offering incentive programs to make "green" energy a more economically viable option. In Canada the RESOP (Renewable Energy Standard Offer Program), introduced in 2006, and updated in 2009 with the passage of the Green Energy Act, allows residential homeowners in Ontario with solar panel installations to sell the energy they produce back to the grid (i.e., the government) at 42¢/kWh, while drawing power from the grid at an average rate of 6¢/kWh (see feed-in tariff). The program is designed to help promote the government's green agenda and lower the strain often placed on the energy grid at peak hours. In March, 2009 the proposed FIT was increased to 80¢/kWh for small, roof-top systems (≤10 kW).

 

from:wiki

A solar cell, or photovoltaic cell (PV), is a device that converts light into electric current using the photoelectric effect. This is based on the discovery by Alexandre-Edmond Becquerel who noticed that some materials release electrons when hit with rays of photons from light, which produces an electrical current. The first solar cell was constructed by Charles Fritts in the 1880s. Although the prototype selenium cells converted less than 1% of incident light into electricity, both Ernst Werner von Siemens and James Clerk Maxwell recognized the importance of this discovery. Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin created the silicon solar cell in 1954. These early solar cells cost 286 USD/watt and reached efficiencies of 4.5–6%.

Solar power has great potential, but in 2008 supplied less than 0.02% of the world's total energy supply. There are many competing technologies, including fourteen types of photovoltaic cells, such as thin film, monocrystalline silicon, polycrystalline silicon, and amorphous cells, as well as multiple types of concentrating solar power. It is too early to know which technology will become dominant.

The earliest significant application of solar cells was as a back-up power source to the Vanguard I satellite in 1958, which allowed it to continue transmitting for over a year after its chemical battery was exhausted. The successful operation of solar cells on this mission was duplicated in many other Soviet and American satellites, and by the late 1960s, PV had become the established source of power for them. After the successful application of solar panels on the Vanguard satellite it still was not until the energy crisis, in the 1970s, that photovoltaic solar panels gained use outside of back up power suppliers on spacecraft. Photovoltaics went on to play an essential part in the success of early commercial satellites such as Telstar, and they remain vital to the telecommunications infrastructure today.

The high cost of solar cells limited terrestrial uses throughout the 1960s. This changed in the early 1970s when prices reached levels that made PV generation competitive in remote areas without grid access. Early terrestrial uses included powering telecommunication stations, offshore oil rigs, navigational buoys and railroad crossings. These off-grid applications accounted for over half of worldwide installed capacity until 2004.

The 1973 oil crisis stimulated a rapid rise in the production of PV during the 1970s and early 1980s. Economies of scale which resulted from increasing production along with improvements in system performance brought the price of PV down from 100 USD/watt in 1971 to 7 USD/watt in 1985. Steadily falling oil prices during the early 1980s led to a reduction in funding for photovoltaic R&D and a discontinuation of the tax credits associated with the Energy Tax Act of 1978. These factors moderated growth to approximately 15% per year from 1984 through 1996.

Since the mid-1990s, leadership in the solar water heater has shifted from the US to Japan and Europe. Between 1992 and 1994 Japan increased R&D funding, established net metering guidelines, and introduced a subsidy program to encourage the installation of residential PV systems. As a result, PV installations in the country climbed from 31.2 MW in 1994 to 318 MW in 1999, and worldwide production growth increased to 30% in the late 1990s.

Germany became the leading PV market worldwide since revising its feed-in tariffs as part of the Renewable Energy Sources Act. Installed PV capacity in Germany has risen from 100 MW in 2000 to approximately 4,150 MW at the end of 2007. After 2007, Spain became the largest PV market after adopting a similar feed-in tariff structure in 2004, installing almost half of the photovoltaics (45%) in the world, in 2008, while France, Italy, South Korea and the U.S. have seen rapid growth recently due to various incentive programs and local market conditions. The power output of domestic photovoltaic devices is usually described in kilowatt-peak (kWp) units, as most are from 1 to 10 kW.

Concentrating photovoltaics (CVP) are another new method of electricity generation from the sun. CPV systems employ sunlight concentrated onto photovoltaic surfaces for the purpose of electrical power production. solar water heater of all varieties may be used, which are often mounted on a solar tracker in order to keep the focal point upon the cell as the sun moves across the sky. Tracking can increase flat panel photovoltaic output by 20% in winter, and by 50% in summer.

 

from:wiki

A legend claims that Archimedes used polished shields to concentrate sunlight on the invading Roman fleet and repel them from Syracuse. Auguste Mouchout used a parabolic trough to produce steam for the first solar steam engine in 1866.

Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. The concentrated heat is then used as a heat source for a conventional power plant. A wide range of concentrating technologies exists; the most developed are the parabolic trough, the concentrating linear fresnel reflector, the Stirling dish and the solar power tower. Various techniques are used to track the Sun and focus light. In all of these systems a working fluid is heated by the concentrated sunlight, and is then used for power generation or energy storage.

A parabolic trough consists of a linear parabolic reflector that concentrates light onto a receiver positioned along the reflector's focal line. The receiver is a tube positioned right above the middle of the parabolic mirror and is filled with a working fluid. The reflector is made to follow the Sun during the daylight hours by tracking along a single axis. Parabolic trough systems provide the best land-use factor of any solar technology. The SEGS plants in California and Acciona's Nevada Solar One near Boulder City, Nevada are representatives of this technology.  The Suntrof-Mulk parabolic trough, developed by Melvin Prueitt, uses a technique inspired by Archimedes' principle to rotate the mirrors.

Concentrating Linear Fresnel Reflectors are CSP-plants which use many thin mirror strips instead of parabolic mirrors to concentrate sunlight onto two tubes with working fluid. This has the advantage that flat mirrors can be used which are much cheaper than parabolic mirrors, and that more reflectors can be placed in the same amount of space, allowing more of the available sunlight to be used. Concentrating linear fresnel reflectors can be used in either large or more compact plants.

A Stirling solar dish, or dish engine system, consists of a stand-alone parabolic reflector that concentrates light onto a receiver positioned at the reflector's focal point. The reflector tracks the Sun along two axes. Parabolic dish systems give the highest efficiency among CSP technologies. The 50 kW Big Dish in Canberra, Australia is an example of this technology. The Stirling solar dish combines a parabolic concentrating dish with a Stirling heat engine which normally drives an electric generator. The advantages of Stirling solar over photovoltaic cells are higher efficiency of converting sunlight into electricity and longer lifetime. A solar water heater uses an array of tracking reflectors (heliostats) to concentrate light on a central receiver atop a tower. Power towers are more cost effective, offer higher efficiency and better energy storage capability among CSP technologies. The Solar Two in Barstow, California and the Planta Solar 10 in Sanlucar la Mayor, Spain are representatives of this technology.

A solar bowl is a spherical dish mirror that is fixed in place. The receiver follows the line focus created by the dish (as opposed to a point focus with tracking parabolic mirrors).
Solar energy is not available at night, making energy storage an important issue in order to provide the continuous availability of energy. Both wind power and solar power are intermittent energy sources, meaning that all available output must be taken when it is available and either stored for when it can be used, or transported, over transmission lines, to where it can be used. Wind power and solar power can be complementary, in locations that experience more wind in the winter and more sun in the summer, but on days with no sun and no wind the difference needs to be made up in some manner.

The Solar Two used this method of energy storage, allowing it to store enough heat in its 68 m³ storage tank to provide full output of 10 MWe for about 40 minutes, with an efficiency of about 99%. Salts are an effective storage medium because they are low-cost, have a high specific heat capacity and can deliver heat at temperatures compatible with conventional power systems, have the potential to eliminate the intermittency of solar power, by storing spare solar power in the form of heat; and using this heat overnight or during periods that solar panel manufacturer is not available to produce electricity. This technology has the potential to make solar power dispatchable, as the heat source can be used to generate electricity at will. Solar power installations are normally supplemented by storage or another energy source, for example with wind power and hydropower.

Off-grid PV systems have traditionally used rechargeable batteries to store excess electricity. With grid-tied systems, excess electricity can be sent to the transmission grid. Net metering programs give these systems a credit for the electricity they deliver to the grid. This credit offsets electricity provided from the grid when the system cannot meet demand, effectively using the grid as a storage mechanism. Credits are normally rolled over month to month and any remaining surplus settled annually.

Pumped-storage hydroelectricity stores energy in the form of water pumped when surplus electricity is available, from a lower elevation reservoir to a higher elevation one. The energy is recovered when demand is high by releasing the water: the pump becomes a turbine, and the motor a hydroelectric power generator.

Combining power sources in a power plant may also address storage issues. The Institute for Solar Energy Supply Technology of the University of Kassel pilot-tested a combined power plant linking solar, wind, biogas and hydrostorage to provide load-following power around the clock, entirely from renewable sources.

 

from:wiki