Pressure-equalizing PV assembly and method

• US 6,809,253 B2
• Filed: 03/07/2003
• Issued: 10/26/2004
• Est. Priority Date: 07/10/2001
• Status: Expired due to Term

• Current Assignee: Totalenergies Onetech
• Original Assignee: PowerLight Corp. (Totalenergies Se)
• Inventors: Dinwoodie, Thomas L.
• Primary Examiner(s): DIAMOND, ALAN D
• Application Number:
  US10/384,513
• Publication Number:
  US 20030164187A1
• Time in Patent Office: 599 Days
• Field of Search: 136/251, 136/244, 136/291, 521/733, 438/64, 257/433
• US Class Current: 136/251
• CPC Class Codes: F24S 2025/02 Ballasting means
• CPC Class Codes: F24S 25/10 extending in directions away from a supporting surface
• CPC Class Codes: F24S 25/615 for fixing to protruding parts of buildings, e.g. to corrugations or to standing seams
• CPC Class Codes: F24S 25/65 for coupling adjacent supporting elements, e.g. for connecting profiles together
• CPC Class Codes: F24S 25/67 for coupling adjacent modules or their peripheral frames for fixing modules or their peripheral frames to supporting elements F24S25/63
• CPC Class Codes: F24S 40/85 Arrangements for protecting solar collectors against adverse weather conditions F24S40/10 takes precedence
• CPC Class Codes: H02S 20/24 specially adapted for flat roofs
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02E 10/47 Mountings or tracking
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y10S 136/291 Applications

Abstract

Each PV assembly of an array of PV assemblies comprises a base, a PV module and a support assembly securing the PV module to a position overlying the upper surface of the base. Vents are formed through the base. A pressure equalization path extends from the outer surface of the PV module, past the PV module, to and through at least one of the vents, and to the lower surface of the base to help reduce wind uplift forces on the PV assembly. The PV assemblies may be interengaged, such as by interengaging the bases of adjacent PV assemblies. The base may include a main portion and a cover and the bases of adjacent PV assemblies may be interengaged by securing the covers of adjacent bases together.

Claims

1. An array of pressure-equalizing photovoltaic (PV) assemblies mountable to a support surface, each PV assembly comprising:

a base having an upper surface and a lower surface;

a PV module having an inner surface, an outer surface and a peripheral edge;

a support assembly securing the PV module to a position overlaying the upper surface of the base;

vents formed through the base; and

a pressure equalization path extending from the outer surface of the PV module, past the PV module, to and through at least one of said vents, and to the lower surface of the base, whereby pressure equalization between the outer surface of the PV module and the lower surface of the base is provided to help reduce wind uplift forces on the PV assembly.

2. The array according to claim 1 wherein adjacent ones of said PV assemblies engage one another so wind uplift forces on one of said PV assemblies tend to transfer to adjacent PV assemblies so to help counteract said wind uplift forces.

3. The array according to claim 1 wherein adjacent ones of said PV assemblies engage at at least one of the bases, the PV modules and the support assemblies so wind uplift forces on one of said PV assemblies tend to transfer to adjacent PV assemblies so to help counteract said wind uplift forces.

4. The array according to claim 1 wherein the base comprises an electrical conductor, and further comprising electrical ground connectors between the electrical conductors.

5. The array according to claim 1 wherein the bases of adjacent PV assemblies are interengaged so wind uplift forces on one of said PV assemblies tend to transfer to adjacent PV assemblies so to help counteract said wind uplift forces.

6. The array according to claim 1 wherein said vents have a total cross-sectional area of V and the PV module has a total surface area of P and the percentage of V to P is about 0.02% to 50% thereby aiding the ability to use a 1W assembly having a weight of about 5-25 kg per square m while avoiding the need for attachment of the PV assembly to the support surface.

7. The array according to claim 1 wherein said vents have a total cross-sectional area of V and the PV module bas a total surface area of P and the percentage of V to P is about 0.05% to 5% thereby aiding the ability to use a PV assembly having a weight of about 5-25 kg per square m while avoiding the need for attachment of the PV assembly to the support surface.

8. The array according to claim 1 wherein said vents have a total cross-sectional area of V and the PV module has a total surface area of P and the percentage of V to P is about 0.07% to 2% thereby aiding the ability to use a PV assembly having a weight of about 5-25 kg per square iii while avoiding the need for attachment of the PV assembly to the support surface.

9. The array according to claim 1 wherein said vents have a total cross-sectional area of V and the PV module has a total surface area of P and the percentage of V to P is at least about 0.02% thereby aiding the ability to use a PV assembly having a weight of about 5-25 kg per square m while avoiding the need for attachment of the PV module to the support surface.

10. The array according to claim 1 wherein said vents have a total cross-sectional area of V and the 1W module has a total surface area of P and the percentage of V to P is at least about 0.07% thereby aiding the ability to use a PV assembly having a weight of about 5-25 kg per square m while avoiding the need for attachment of the PV module to the support surface.

11. The array according to claim 1 wherein the inner surface of the PV module is separated from the upper surface of the base.

12. The array according to claim 1 wherein at least one of said vents is positioned generally centrally beneath the PV module.

13. The array according to claim 1 wherein the support assembly is a multi-position support assembly and comprises first and second parts securing the PV module to the base at shipping and inclined-use angles relative to the base, said shipping angle being generally 0 degrees, said inclined-use angle being a first acute angle with the PV module extending away from the base.

14. The array according to claim 13 further comprising:

a deflector, and

a multi-position deflector support securing the deflector to the base at deflector shipping and deflector inclined-use angles relative to the base, said deflector shipping angle being generally 0 degrees, said deflector inclined-use angle being a second acute angle with the deflector extending away from the base.

15. The array according to claim 1 wherein the array of PV modules is circumscribed by a perimeter assembly.

16. The array according to claim 15 wherein the perimeter assembly is a continuous, belting perimeter assembly, and further comprising cross-strapping, extending at least one of above, below or through the array, securing a first position along the perimeter assembly to at least a second position along the perimeter assembly thereby stabilizing the array against wind up-lift forces.

17. A PV system comprising:

a support surface;

an array of pressure-equalizing photovoltaic (PV) assemblies mounted to the support surface, each PV assembly comprising;

a base having an upper surface and a lower surface;

a PV module having an inner surface, an outer surface and a peripheral edge;

a support assembly securing the PV module to a position overlying the upper surface of the base;

vents formed through the base; and

a pressure equalization path extending from the outer surface of the PV module, past the PV module, to and through at least one of said vents, and to the lower surface of the base, whereby pressure equalization between the outer surface of the PV module and the lower surface of the base is provided to help reduce wind uplift forces on the PV assembly; and

the peripheral edges of adjacent PV modules being separated by an average distance of about d.

18. A PV assembly, for use on a support surface, comprising:

a base having an upper surface and a lower surface;

a PV module having an inner surface, an outer surface and a peripheral edge;

a module support assembly securing the PV module to a position overlying the upper surface of the base;

the PV module being oriented at a first angle to the base, the PV module extending away from the base from a first module portion to a second module portion;

a deflector oriented at a second angle to the base by a deflector support, the deflector having first and second deflector portions, the deflector extending away from the base from the first deflector portion to the second deflector portion;

vents formed through the base; and

a pressure equalization path extending from the outer surface of the PV module, past the deflector, to and through at least one of said vents, and to the lower surface of the base, whereby pressure equalization between the outer surface of the PV module and the lower surface of the base is provided to help reduce wind uplift forces on the PV assembly.

19. A PV system comprising:

a support surface comprising alternating ridges and troughs; and

an array of pressure-equalizing photovoltaic (PV) assemblies, each of a plurality of said PV assemblies comprising;

a base having an upper surface and a lower surface;

a PV module having an inner surface, an outer surface, a center and a peripheral edge;

a support assembly securing the PV module to a position overlying the upper surface of the base;

a vent formed through the base between the center of the PV module and the support assembly;

a pressure equalization path extending from the outer surface of the PV module, past the PV module, to and through said vent, and to the lower surface of the base; and

whereby pressure equalization between the outer surface of the PV module and the lower surface of the base is provided to help reduce wind uplift forces on the PV assembly.

20. A method for reducing wind uplift forces on an array of pressure-equalizing photovoltaic (PV) assemblies mountable to a support surface, each PV assembly comprising a base having an upper surface and a lower surface, a PV module having an inner surface, an outer surface and a peripheral edge, and a support assembly securing the PV module to a position overlying the upper surface of the base, the method comprising:

forming vents through the base; and

creating a pressure equalization path extending from the outer surface of the PV module, past the PV module, to and through at least one of said vents, and to the lower surface of the base, whereby pressure equalization between the outer surface of the PV module and the lower surface of the base is provided to help reduce wind uplift forces on the PV assembly.

21. The method according to claim 20 further comprising interengaging adjacent ones of said PV assemblies so wind uplift forces on one of said PV assemblies tend to transfer to adjacent PV assemblies so to help counteract said wind uplift forces.

22. The method according to claim 20 further comprising selecting a base comprising an electrical conductor, and further comprising electrically grounding the electrical conductors of adjacent ones of said PV assemblies.

23. The method according to claim 20 wherein said vents forming step is carried out so said vents for one PV assembly have a total cross-sectional area of V and the PV module has a total surface area of P and the percentage of V to P is about 0.02% to 50% thereby aiding the ability to use a PV assembly having a weight of about 5-25 kg per square m while avoiding the need for attachment of the PV assembly to the support surface.

24. The method according to claim 20 wherein said vents Conning step is carried out so said vents for one PV assembly have a total cross-sectional area of V and the PV module has a total surface area of P and the percentage of V to P is about 0.05% to 5% thereby aiding the ability to use a PV assembly having a weight of about 5-25 kg per square m while avoiding the need for attachment of the PV assembly to the support surface.

25. The method according to claim 20 wherein said vents forming step is carried out so said vents for one PV assembly have a total cross-sectional area of V and the PV module has a total surface area of P and the percentage of V to P is about 0.07% to 2% thereby aiding the ability to use a PV assembly having a weight of about 5-25 kg per square m while avoiding the need for attachment of the PV assembly to the support surface.

26. The method according to claim 20 wherein said vents forming step is carried out so said vents for one PV assembly have a total cross-sectional area of V and the PV module has a total surface area of P and the percentage of V to P is at least about 0.02% thereby aiding the ability to use a PV assembly having a weight of about 5-25 kg per square m while avoiding the need for attachment of the PV assembly to the support surface.

27. The method according to claim 20 wherein said vents forming step is carried out so said vents for one PV assembly have a total cross-sectional area of V and the PV module has a total surface area of P and the percentage of V to P is at least about 0.07% thereby aiding the ability to use a PV assembly having a weight of about 5-25 kg per square m while avoiding the need for attachment of the PV assembly to the support surface.

28. The method according to claim 20 further comprising orienting the PV module at a first angle to the base so that the PV module extends away from the base from a first module portion to a second module portion.

29. The method according to claim 28 further comprising mounting a deflector, having first and second deflector portions, to the base so that the deflector extends away from the base from the first deflector portion to the second deflector portion.

30. The method according to claim 29 further comprising forming a gap between the second module and deflector portions.

31. The method according to claim 30 wherein said gap forming step is carried out so that at least some of said vents are generally vertically aligned or coincident with said gap.

32. The method according to claim 31 wherein said vents and gap forming steps are carried out so the outer surfaces of the PV modules have a total area equal to about m and the total cross-sectional area of said vents that are generally vertically aligned with said gaps is about w, the percentage of w to m being about 0.1% to 50%.

33. The method according to claim 31 wherein said vents and gap forming steps are carried out so the outer surfaces of the PV modules have a total area equal to about m and the total cross-sectional area of said vents that are generally vertically aligned with said gaps is about w, the percentage of w to in being about 0.4% to 5%.

34. The method according to claim 30 wherein the gap forming step comprises providing at least one hollow conduit fluidly coupling the gap and said at least one of said vents.

35. The method according to claim 20 wherein said path creating step creates a constrained leakage path along said unobstructed path portion.

36. A method for reducing wind uplift forces on an array of pressure-equalizing photovoltaic (PV) assemblies mountable to a support surface comprising alternating ridges and troughs, each PV assembly comprising a base having an upper surface and a lower surface, a PV module having an inner surface, an outer surface and a peripheral edge, and a support assembly securing the PV module to a position overlying the upper surface of the base, the method comprising:

forming vents through the base;

creating pressure equalization paths extending from the outer surfaces of the PV modules, past the PV modules, to and through at least one of said vents, and to the lower surface of the base, whereby pressure equalization between the outer surfaces of said PV modules and the lower surface of the base is provided to help reduce wind uplift forces on the PV assembly; and

mounting the array of PV assemblies to the support surface.