The racking and mounting system of a solar PV installation normally consist of 10% to 25% of the total cost of the installation. However, the related roof maintenance costs are rarely included in the solar PV financial calculations. All the racking equipment requires roof penetration which can lead to water leaks and also may void the roof warranty. To avoid such costly mistakes the solar PV system should be installed according to municipal code and installation manuals.
Thus, installers and homeowners must be cautious in regards to which roof mounting systems they select.
There are four important measures for selecting a roof mounting system:
- The cost of the system: The lower, the better.
- The life-span and reliability: The mounting system must last for at least 25 years. (which is the normal life span of a solar PV installation)
- Ease of mounting: The installation may take a long time relevant to the rest of the project and can require high attention to detail. These circumstances can increase labor costs and may result in improper installation.
- Code compliance: The use of flashings may be necessary for the system to not cause any water leaks or electricity grounding hazards.
I have conducted some brief research on flashings and mounting solutions available on the market. CivicSolar carries most roof mounting solutions, so you can do your own comparison here. The below table represents a brief comparison of the flashings and attachments.
Because of the variety of styles and additional considerations necessary, I do not take rails and racking equipments into consideration. That is a topic on its own. The items that I compare are the pieces of equipment between the rails and the roofing, where the actual attachment happens.
Quick Mount PV
|Link to products||click here>||click here>||click here>||click here>||click here>||click here>|
|Required Extra Flashing||Flashing for 1/2" - 1-1/8" O.D. shaft||Flashing for 1/2" - 1-1/8" O.D. shaft||Flashing for 1" O.D. shaft||Included||ezFlush-Mount Flashing||Included|
|Required Extra Hardware||Included||Included||Included||Included||Included||5/16" lag screws|
|Ease of Installation||Easy to Moderate||Moderate||Easy to Moderate||Very Easy||Easy||Easy|
|Code Compliance||Compliant with flashing||Compliant with flashing||Compliant with flashing||Compliant||Compliant with flashing||Compliant|
|Product Cost||Low||Low||Lowest||Medium||Low to Medium||Low to Medium|