1. Field of the Invention
The present disclosure relates generally to a solar photovoltaic panel, particularly to a building-integrated photovoltaic panel.
2. Background
The efficiency of solar photovoltaic panel is dependent on the angle of the light radiated on the solar cell. For application in building-integrated photovoltaic, to maximize solar access and power output, the orientation and the tilt angle of the arrays are optimized. The orientation and the tilt angle of the arrays can be optimized relative to the geographical location. Demonstrations have shown that a system installed at a tilt angle equivalent to the site latitude produces the greatest amount of electricity on an annual basis. In comparison to a system's performance at latitudes angle, the annual performance losses for vertical façade systems can be as high as 50%, while annual performance losses for façade systems can be as high as 10% for horizontal installation.
Facades offer a large area for solar panels. Besides generating electricity, solar facades can be integrated with window, day lighting, shading schemes to provide multiple benefits. The typical building skin façade is vertical and has a face that faces southwards. However, vertical oriented solar panels mostly have much reduced electricity output compared to panels sloped towards the sun. The reduction in output is greatest in the summer when the sun is high in the sky. Coincidentally, summer is also when electricity is the most valuable. Optimizing solar panel performance in building wall applications will usually require more complex detailing and therefore higher construction costs in order to accommodate optimal orientations to the sun. Currently there are a number of solutions in an attempt to improve efficiency and energy output of solar panel used in building. Some of these solutions attempt to make a sloped wall. The solutions of the prior art generally have drawbacks and reduce the effective floor areas at perimeter of the building. The prior solutions also reduce building area per site area and the solutions increase cost to construct. Other solutions attempt to use a saw tooth configuration or an accordion wall configuration, but these solutions have complex curtain wall constructions, which are hard to manufacture and also potentially has problems, when cleaning. Still other solutions seek to use solar cell blind to track the sun. But this configuration also has performance loss from shading effects. This configuration also has reliability issues.
For installation on a flat roof top, solar panels are tilted at a favorable angle by using mounting structures. The mounting structures cause detrimental issues. These may include a high system cost and a complex installation or a large weight load. Sometimes mounting of the panels may even cause mechanical damage to the roof. Also the shading on a panel from adjacent panels will cause performance loss, as well as reliability issues. To avoid this problem, panels are placed separated from one other by a large distance from each other to avoid shading, which can block the solar cell. As a result, the effective area from the sun to expose the solar panels is reduced. Also for a fixed roof area and a fixed shape, due to the fixed dimension of a solar cell panel, there will be wasted area on the edges. This can result in losses, which can be high due to the large dimension of a solar panel.
For locations with latitude at 0 degrees, most roof tops are constructed to be sloped due to rain and drainage. However, the solar energy efficiency is the highest when the solar cell is horizontal.
It would be desirable to have a solar panel that has less performance dependency on design. More often than not, the strong performance dependency on design makes designers view the solar cell design as a limitation rather than an opportunity to exploit. Many architects and clients feel that solar architecture implies rigid design limitations. These limitations are regarding orientation, placement of windows, sloping roof elements, sun spaces and so on. This is not necessarily true as discovered by the present inventors.
It would be desirable to have a device that generate electricity from solar, which has high efficiency even at a standard vertical building structure, without adding complexity in building design.
It would be desirable to have a solar panel that has high solar efficiency with a standard building construction, which has lower cost, better appearance, standard dimension, and a better design flexibility.
Furthermore, it would also be desirable to have a solar panel that has a high solar efficiency without sacrificing building floor area as compared with a sloped building wall with a conventional solar panel. Building floor area is a precious commodity. In some cases, such as sloped curtain wall, the solar panel configurations reduce the amount of usable perimeter floor area. This is attributed to the fact that the wall effectively ‘cuts back’ on floor area as the building gets taller. Any reduction in usable floor area needs to be considered when evaluating the life-cycle costs of a solar system.
Furthermore, it would be desirable to have a solar panel to form the building structure with accessibility for frequent maintenance and cleaning of the panels from the exterior of the building. It is critical to ensure that panel stays clean or can be cleaned to keep efficiency. Solar panel performance is highly dependent upon its ability to remain clean. Complicated construction designs, such as “saw tooth”, or “accordion”, have issues in that these configurations are difficult to clean. This in turn may affect the provision for cleaning tracks or fasteners in curtain wall systems and may increase operating costs.
Furthermore, it would be desirable to have a solar panel that can be installed on roof top with the panel having optimized energy efficiency without any special mounting system to tilt the panel against the roof top. The present disclosure provides that the solar cell can be tilted to optimum angle while panel is simply mounted on the roof top.
Still further, it would be desirable to have solar panels in a building structure, which would not lose significant energy efficiency from the partial shading from adjacent panel. Even partial shading on the panel will decrease the energy output. Profiled mounting constructions, in particular such as awnings, can produce shade. This shade falls along the edge of the adjacent panel. The shade will result in a loss of efficiency. This also may cause reliability problems. In general, panels need a large distance between the panels. This large distance avoids this shading effect. However, the configuration has some major drawbacks, including that the total area of solar panels is reduced, the configuration has a lower sun angle in spring and fall, there is too much sun exposed through the large distance.
Still further, it would be desirable to have solar panels that are adjustable to optimize heat load. It is desirable to have solar cells with a high angled direct sunlight parameter to reduce heat load.
Still further, it would be desirable to have solar panels that are adjustable to optimize the daylight. The present disclosure may provide that the solar cells preferably shade high angle direct sunlight and allow diffuse light in through the space between solar cells. Diffuse light provides more comfortable lighting.
Still further, it would also be desirable to have a solar panel that has more solar cell area, so the cell can generate more electricity. Standard panel has a solar cell area at panel area minus empty space on panel surface. With angled solar cells inside panels, solar cell area can be larger than the panel area.
Still further, it would also be desirable to have a solar panel using reflector. The reflector may collect sunlight on empty spaces between adjacent solar cells to improve panel efficiency. With angled and spaced solar cells, angled reflectors that are inserted in between adjacent solar cells can guide the sunlight to the surface of solar cells.
Still further, it would be desirable to have a device that can form a curved solar panel to provide the flexibility in architectural design. Still further, it would be desirable to have a curved solar panel with internal solar cells having similar angles of incidence to avoid mismatch. Patterns can be designed to align solar cells. This design may point to the sun at the same angle even when the panel is curved.
Still further, it is desirable to have solar panels that optimize solar cell orientation as well. A vertical saw tooth design is used to obtain good solar performances in certain orientations. However, this design created multiple “corner” windows, which is not favorable. With the present disclosure, a vertical straight curtain wall can be built, and the internal solar cells will form the preferred orientation.
Still further, it is desirable to have reliable solar panel. There was solution to have solar sunscreen within a window to track sun. However, due to the moving parts of the design, this configuration includes reliability issues. The present disclosure includes solar cells, which are fully encapsulated in a panel, and thus there is no reliability concern.
Still further, it is desirable to have solar panel without self shading from an adjacent cell. In a solar sunscreen system, as result of tracking the sun, the shading from the above solar cell strongly limits energy yield. The present disclosure uses fixed designed angles and spaces to eliminate or to minimize the self-shading impact from an above or an upper solar cell. The space between solar cells is used to be transparent, as well as avoiding shading on an adjacent solar cell.
Therefore, there currently exists a need in the industry for a device and associated method that has a number of solar cells that are angled and that are spaced inside the panel.
The present disclosure advantageously fills the aforementioned deficiencies by providing a method to make solar photovoltaic panels with internal angled solar cells. The present disclosure device is unique when compared with other known devices and solutions because the present disclosure provides: a solar cell is strip shaped and rotated along the strip to form an angle with the surface of the solar panel. The solar cell points to sunlight at a favorable angle with a simple construction and solar cells are spaced to minimize shading from an adjacent cell and connectors are patterned to assemble with the angled solar cells. The solar cell may also include a patterned holder, or a front cover, or a back cover, which can be used to support the solar cell. The solar cell may further include an insert unit. The insert unit can be added in the space between solar cells for functions of insulation, lights, or light collection.
According to a first aspect of the present disclosure there is provided a photovoltaic solar cell unit comprising a first cover and a second cover. The second cover is generally parallel to the first cover. The second cover is spaced from the first cover and the first and the second cover have a longitudinal axis. The photovoltaic solar cell unit also includes a solar cell. The solar cell disposed between the first cover and the second cover with the solar cell being disposed at a predetermined angle relative to the longitudinal axis.
According to another aspect of the present disclosure there is provided a photovoltaic solar cell unit comprising a first cover having a longitudinal axis and a solar cell disposed at a predetermined angle relative to the longitudinal axis.
According to yet another aspect of the present disclosure there is provided a photovoltaic solar cell unit comprising a first cover and a second cover being generally parallel to the first cover. The second cover is spaced from the first cover and the first and the second cover have a longitudinal axis. The second cover is adapted to be supported on an inclined surface and a solar cell is disposed between the first cover and the second cover. The solar cell is disposed at a predetermined angle relative to the inclined surface. The solar cell is generally horizontal notwithstanding the inclined surface.
In another embodiment there is provided a photovoltaic solar cell unit comprising a first cover and a second cover being generally parallel to the first cover. The second cover is spaced from the first cover and the first and the second cover having a longitudinal axis and a solar cell is disposed between the first cover and the second cover and the solar cell is supported on a curved surface.
In another embodiment there is provided a photovoltaic solar cell unit comprising a first cover and a second cover being generally parallel to the first cover with the second cover being spaced from the first cover and the first and the second cover have a longitudinal axis. The photovoltaic solar cell unit has a solar cell disposed between the first cover and the second cover with the solar cell being disposed at a predetermined angle relative to the longitudinal axis. The photovoltaic solar cell unit also has a holder between the first cover and the second cover for supporting the solar cell.
The present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, which are intended to be read in conjunction with both this summary, the detailed description and any preferred and/or particular embodiments specifically discussed or otherwise disclosed. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of illustration only and so that this disclosure will be thorough, complete and will fully convey the full scope of the disclosure to those skilled in the art.
The present disclosure is directed to a method to make a solar panel, particularly for building integrated photovoltaic panel. The present disclosure is directed to a solar panel with an internal angled and spaced number of solar cells, which is made up of the following components, but not limited to: a) at least one solar cell, b) connector, c) a front cover, d) a back cover and e) encapsulant. The processes to make the solar panel include a) a process to design angles of solar cells, b) a process to design the width of solar cell, c) a process to design the space between solar cells, d) a process to assemble solar cells and e) a process to form a solar panel.
Examples related to the disclosure are disclosed. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, to one having ordinary skill in the art, it will be apparent that the specific detail need not be employed to practice the present disclosure. Well-known methods related to the implementation are not described in detail in order to obscuring the present disclosure.
Furthermore, the method associated with the present disclosure may also include a process for producing a curved solar panel.
Another embodiment of the present disclosure includes a solar panel with pattern 807 on a front cover or a back cover to support solar cells. As an example, the patterned glass can be used as a front cover or a back cover. The pattern supports solar cells.
Furthermore, the subject matter of the present disclosure is a process for producing a solar panel. The process makes available a body comprising a number of solar cell units with the solar cell units being parallel to each other, while cell surface is tilted to the panel surface at an angle. The solar cell is preferred to be strips and the solar cell can be rotated along the strip. There are different options within the scope of the present disclosure. One example is that crystalline Si solar cell is sliced into a number of strips. Another example is that the present disclosure may include a number of flat thin film solar cell is sliced into strips. Another example is that the present disclosure may include a thin film solar cell being directly formed on strips.
In additional to changing tilted angle, the present disclosure may include a differently configured solar cell orientation as well. The current vertical saw tooth design is preferably used to obtain an improved solar performance in certain orientations. However, this design created multiple “corner” windows, which is not favorable. With the present disclosure, the vertical straight curtain wall can be built, while internal solar cells form a preferred orientation.
Another embodiment of the present disclosure includes a pattern on the front side of the front cover. Pattern preferably is intended to reduce the reflective light loss at the panel surface. Due to the refractive index mismatch between air and glass, a portion of the sunlight is reflective back to air at the interface of the air and the glass. The ratio of reflection increases with a decrease of the angle between the light and the interface. For a standard solar glass, the reflection percentage is 4.0% at 90°, 5.77% at 50°, and 8.9% at 60°. With the pattern on the panel surface, the glass interface is tilted toward the sun. This reduces the incidence angle by the tilted angle of the pattern.
Solar cells are separated from each other by a space having a predetermined distance. The space preferably avoids the shading from an adjacent cell. When the panel is translucent, such as glass-on-glass, the space provides for daylight control and heat load control. The amount of sunlight may be controlled and the solar panel may receive more diffused light, and less direct light, or more light in the summer, or more light in morning and afternoon, and less night at noon. Heat load may also be controlled. For example, more heat load in winter, or less heat load in summer, or more heat load in morning and afternoon, and less heat load at noon.
Furthermore, the method associated with the present disclosure may also include inserting a unit 1005 into the space between solar cells to provide functionality. The insert unit 1005 can be different types, such as insulator, bypass diode, LED diode, or light reflector or any other unit 1005 that provides functionality.
Furthermore, the method may also include a process for producing a thin film solar cell on a patterned front cover or a back cover. The benefit is higher energy output and efficiency. This results in a larger solar access of the solar cell and an improved sun incident angle and improved thin film solar cell area.
Furthermore, the method associated with the present disclosure may also include a process to direct light in a space formed in the solar cell so that same electricity generation can be realized by fewer solar cells.
While the present disclosure has been described above in terms of specific embodiments, it is to be understood that the disclosure is not limited to these disclosed embodiments. Many modifications and other embodiments of the disclosure will come to mind of those skilled in the art to which this disclosure pertains, and which are intended to be and are covered by both this disclosure and the appended claims. It is indeed intended that the scope of the disclosure should be determined by proper interpretation and construction of the appended claims and their legal equivalents, as understood by those of skill in the art relying upon the disclosure in this specification and the attached drawings.
The instant patent application claims priority to U.S. Provisional Patent Application No. 61/276,386 to Luo et al. filed on Sep. 12, 2009, and which is herein incorporated by reference in its entirety and claims priority to U.S. Provisional Patent Application No. 61/276,387 to Luo et al., which has common inventors and filed on Sep. 12, 2009, and which is also herein incorporated by reference in its entirety.
Number | Date | Country | |
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61276386 | Sep 2009 | US | |
61276387 | Sep 2009 | US |