Roof mounting bracket for photovoltaic power generation system

Abstract

Multiple brackets are used together to support photovoltaic cells upon a roof. Each bracket includes a mounting rail at an upper side and a bottom rail at a lower side. The bottom rail of one bracket is configured to overlap the mounting rail of another bracket. Lateral joints on each bracket overlap each other to connect adjacent panels of photovoltaic cells. Cell support structures are interposed between the mounting rail and bottom rail to support a photovoltaic stack assembly thereon. Wind clips allow the bottom rail of a higher bracket to be interconnected with a mounting rail of a lower bracket. An undulating end piece allows airflow to enter beneath a lowest bracket and pass up beneath the brackets to provide cooling air for the overall system of photovoltaic cells mounted upon the brackets. Edge flashing precludes water migration laterally at edges of the panels.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 12 / 456,079, filed on Jun. 10, 2009.FIELD OF THE INVENTION[0002]The following invention relates to mounting systems for mounting photovoltaic cells on roofs of buildings. More particularly, this invention relates to mounting brackets and bracketless systems for supporting photovoltaic cells upon roofs in a manner which has a low profile and blends in nicely with adjacent shingles.BACKGROUND OF THE INVENTION[0003]Photovoltaic cells have enjoyed increasing popularity over time as various different technical hurdles associated with the use of photovoltaic cells have been overcome. Photovoltaic cells are generally solid state devices formed of various materials (often silicon) which generate electric current when exposed to photonic radiation, such as solar radiation.[0004]One form of photovoltaic cell is configured so that it can rest upon a bracket which is partic...

AI Technical Summary

Benefits of technology

[0007]With this invention a roof mounting bracket is provided for a photovoltaic power generation system that is particularly configured to allow assemblies of photovoltaic cells to be easily and securely mounted to roofs which have a thin roofing material such as composition roof shingles, slate shingles or other thin planar shingles. The mounting bracket and associated photovoltaic cells are relatively thin and are configured to be sealed in a watertight fashion so that the brackets and assemblies of cells can act effectively as shingles, while also accommodating natural convection air cooling of the brackets and panels to prevent excessive heat from building up and damaging the brackets or panels.

Problems solved by technology

Also, with such a lower profile technical challenges are presented such as how to keep the bracket and cells below temperatures at which damage can occur, and how to secure the bracket and cells to the roof sufficient to resist high wind loads.

Not only does the temperature do damage to the materials forming the bracket, but also thermal forces cause thermal expansion which can lead to distortion or breakage of the cells, or loosening of the mounting system provided by the brackets.

Especially when it is desirable to have the photovoltaic cells blend into the adjacent shingles, such blending tends to block natural convection air circulation cooling, leading to degraded performance.

Such wind loads can be quite extreme in some environments, particularly those which periodically experience hurricanes or other extreme weather phenomena.

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