Some tips and tricks directly from solar mounting and racking manufacturers, including proper waterproofing, residential location, full-package systems and installation plans.
Fixing leaks from residential PV installations costs more than you think.
Jeff Spies, vice president of business development for Quick Mount PV
Waterproofing penetrations for solar mounting is a serious issue. Unfortunately, many underestimate the long term cost impacts of this critical decision.
A solar array on a new roof can last 30 years, but long-term waterproofing is a challenge as mounts flex daily due to wind loads and the difference in expansion/contraction of wood roofing versus the metal PV racking.
Solar waterproofing is a statistical challenge. Solar installations require dozens of penetrations, meaning even a small leak rate can still be a big problem. A “small” 1 percent leak rate after 10 years equates to 30 to 50 percent of your PV installation leaking.
For a 5-kW system, quality flashed solar mounts cost $500 to $1,000 (10 to 20 cents/watt), however, removing/reinstalling the PV system costs $2,500 to $7,500 (50 cents to $1.50/watt) which equates to 25 to 50 percent of the cost of a brand new system, and wood rot or mold damage further increase costs. Fixing leaks will cost most PV owners more than replacing their inverter.
Most customers assume their warranties protect against this risk, but in reality, waterproofing warranties usually last no more than 10 years.
Saving money by economizing on waterproofing could be a costly mistake. In the end, quality solar flashed mounts are cheap insurance.
Most important residential installation concern? Location, location, location.
Russell Eisenman, marketing and social media for Quickscrews International Corp.
The most important consideration for using solar panels is installing them in the proper location and at the correct angle to the sun. Sunlight is important for solar, but even cloudy areas are great for solar energy. What matters more is one’s roof. As long as the roof is free of shade and faces south (east and west are good too, but south is optimal), there will be plenty of sunshine for the panels.
If you live in a place where direct sunlight for continuous periods of time is a challenge, then one may want to consider triple junction laminated panels. This category of panels contains photovoltaic cells which respond to more than one wavelength of light, picking up low-range or indirect light and converting them into electrical energy.
If one’s roof isn’t optimal for solar (faces the wrong direction, made of the wrong materials, etc.), a ground-mounted solar system is a good alternative. People commonly choose ground mounted if there is a lot of space on the property.
As often as possible, go for tabbed solar cells because this will make wiring easier for the installer. It may be a little more expensive, but the convenience is well worth it.
Make sure your racking system for large-scale installations is the full package.
Harman Kaur, marketing manager for RBI Solar
A good solar racking system for large-scale installations should have the following features:
- Fewer Posts — Reduced number of posts leads to faster installation.
- Self-grounded — Utility-scale racking should be ETL classified to UL 2703.
- Built-in Wire Management — This reduces the cost of wire management devices.
- Pre-assembled — Fast on-site installation happens with pre-assembled components.
- String Sizes — A good racking system should accommodate various string sizes.
- Individual Design — Projects should be individually designed to meet local building code requirements.
- Foundation Options — Different foundation options should be available to install the racking.
- Total Cost — Racking cost should include all components including cost of design/complete engineering, posts, racks, mounting hardware, freight to the jobsite and installation of posts/racks.
- Options — Often installation options offered by the racking manufacturer are economical, as they have highly skilled construction crews that install nothing but solar racking.
Figure out a game plan before beginning a job to ensure everything runs smoothly.
Kate Bayard, director of marketing for SolarDock
Visiting the site and developing an installation plan in advance helps the job run smoothly, resulting in less downtime and increased production. Three important things to consider in advance:
- Do the build plans match actual roof conditions? Compare mechanical build plans to as-built roof conditions. Check layout specs to confirm dimensions, location of obstructions, shading or quirky roof features. If anything looks amiss, let the designer know so a solution can be developed before you get on the roof.
- How will equipment be handled and staged? Identify where delivery trucks should unload, how equipment and materials will be lifted to the roof and where they will be staged for maximum efficiency during installation. This avoids confusion on delivery day, helping you get to work sooner.
- Who will do what? Give workers clearly defined jobs that allow them to specialize on a single task. By having only one job, the worker is able to be more efficient and proficient at what they are doing. It also helps the foreman troubleshoot problems because he knows who was responsible for what.