Multifunctional photovoltaic skylight with dynamic solar heat gain coefficient and/or methods of making the same
View Patent ↗Improved building-integrated photovoltaic systems according to certain example embodiments may include concentrated photovoltaic skylights or other windows having a cylindrical lens array. The skylight may include an insulated glass unit, which may improve the Solar Heat Gain Coefficient (SHGC). The photovoltaic skylight and lens arrays may be used in combination with strip solar cells. Arrangements that involve lateral displacement tracking systems, or static systems (e.g., that are fixed at one, two, or more predefined positions) are contemplated herein. Such techniques may advantageously help to reduce cost per watt related, in part, to the potentially reduced amount of semiconductor material to be used for such example embodiments. A photovoltaic skylight may permit diffuse daylight to pass through into an interior of a building so as to provide lighting inside the building, while the strip solar cells absorb the direct sunlight and convert it to electricity, providing for SHGC tuning.
1. A skylight, comprising:
first and second glass substrates arranged substantially in parallel and spaced apart from each other;
a first gap between the first and second glass substrates;
an inert gas in the gap;
a lenticular array provided along a common axis, the lenticular array comprising first and second sub-lens arrays, each sub-lens array comprising plano-convex lenses, the first and second sub-lens arrays being laminated to one another via laminating material comprising polyvinyl butyral (PVB) such that the planar sides of the first and second sub-lens arrays are adjacent to one another and contact the laminating material; and
the second glass substrate supporting a plurality of generally elongate solar cell strips,
wherein the lenticular array and the glass substrates are oriented relative to one another such that the skylight has different solar heat gain coefficients (SHGCs) at the same time of day during at least first and second times of the year, respectively, and wherein the lenticular array and the second substrate are movable with respect to one another, as between at least first and second predefined positions, each said predefined position having an associated SHGC.
2. The skylight of claim 1 , wherein the first and second times of the year correspond to summer and winter months respectively, and wherein the SHGC for the first time of the year is lower than the SHGC for the second time of year.
3. The skylight of claim 1 , wherein the skylight is structured such that each season of the year has a different respectively selected SHGC.
4. The skylight of claim 1 , wherein the skylight is structured such that each month of the year has a different respectively selected SHGC.
5. The skylight of claim 1 , wherein the solar cell strips comprise c-Si.
6. The skylight of claim 1 , wherein the different SHGCs are at least partially controlled by designing the skylight such that different amounts of direct sunlight impinge upon the solar cell strips at corresponding times of the year.
7. The skylight of claim 1 , wherein a majority of the light that may pass through the skylight is diffuse light.
8. The skylight of claim 1 , further comprising a motor, wherein the lenticular array and the second substrate are automatically movable with respect to one another in connection with the motor.
9. The skylight of claim 1 , further comprising means for manually moving the lenticular array and the solar cells relative to one another between the different predefined positions.
10. The skylight of claim 1 , being substantially horizontally and/or vertically disposable on a roof.
11. The skylight of claim 1 , being orientable at a tilt selected in dependence on a latitude where the skylight is to be installed.
12. The skylight of claim 1 , further comprising a programmable controller and a motor, the programmable controller being configured to cause the motor to move the lenticular array and the solar cells relative to one another between the different predefined positions based on a date and/or a temperature reading.
13. The skylight of claim 1 , wherein lenses in the lenticular array are provided along a common cylindrical axis that is substantially parallel to the ground.
14. A building integrated photovoltaic (BIPV) product, comprising:
first and second glass substrates arranged substantially in parallel and spaced apart from each other;
a first gap between the first and second substrates;
an inert gas in the first gap;
a lenticular array comprising first and second sub-lens arrays, each sub-lens array comprising plano-convex lenses, the first and second sub-lens arrays being laminated to one another via laminating material comprising polyvinyl butyral (PVB) such that the planar sides of the first and second sub-lens arrays are adjacent to one another and each of the planar sides contacting the laminating material; and
the second substrate supporting a plurality of generally elongate solar cell strips,
wherein the lenticular array and the substrates are oriented relative to one another and configured such that the product has different solar heat gain coefficients (SHGCs) at the same time of day during at least first and second times of the year, respectively, and such that different amounts of direct sunlight impinge upon the solar cell strips at the first and second times of the year, and wherein the lenticular array and the second substrate are movable with respect to one another, as between at least first and second predefined positions, each said predefined position having an associated SHGC.
15. The BIPV product of claim 14 , wherein the BIPV product is structured such that each season and/or month of the year has a different respectively selected SHGC.
16. The BIPV product of claim 14 , further comprising a motor, wherein the lenticular array and the second substrate are automatically movable with respect to one another in connection with the motor.
17. The BIPV product of claim 14 , being substantially horizontally and/or vertically disposable on a roof and/or orientable at a tilt selected in dependence on a latitude where the skylight is to be installed.