Based on their experience with the Richmond PV project, Eastwood’s engineers, realizing that a better flat-roof mounting system than ones currently available was both possible and needed, initiated design studies. The primary objectives were:

• Adaptability of the system to different roof types and to uneven roof surfaces
• Easy installation
• Easy roof access for maintenance/cleaning
• Provision for varied module tilt angles to maximize energy production at different latitudes
• Multiple options for securing the system to the roof including self-ballasting
• Compatibility with all major brand modules
• Free air circulation to keep the modules cool.

The result of Eastwood’s design studies is the architecture shown below.
The basic building block is a 4 x 1 “row”. Three rows linked “fore and aft” (usually north-south to face the sun) comprise a 12-module electrical string.

The primary structural elements of the 4 x 1 row are the “spars” – two long aluminum pieces attached to the north and south sides of the modules and spanning over 90% of their combined length.

Each 4 x 1 row is supported (attached to the roof) by four tilt brackets which perform both a positioning and structural function.

As shown in the figure below, differential sizing of tilt brackets makes possible differential spacing of module rows to avoid sun shading and allow routine maintenance access to the roof as well as to any module. The interfaces between tilt brackets and the links that connect them are rigid enough to add structural strength to the system while compliant enough to allow the system to follow uneven roof surfaces.

The system allows modules to be arrayed flat, i.e parallel to the roof plane, or to be tilted toward the sun at one of the following angles: 5°, 10°, 15°, or 20°. The greater the tilt angle, the greater the spacing required to avoid sun shading.

Even at the 5° tilt angle, there is sufficient space (about 7 1/2 inches between rows) to allow easy access to all parts of the roof. To further facilitate roof cleaning/maintenance, each 4 x 1 row can be tilted up to vertical by simply removing two fasteners (bolts).