Three key factors behind a successful commercial rooftop solar install

With commercial PV systems being considered as long-term investments of 25 years, it is important to understand how every stage, starting from selection, installation, through operation and maintenance, can impact the longevity and ROI of the system.
Some key considerations in the decision-making process are quality, durability, and reliability.
There are multiple ways in which these three attributes can be designed into all stages of the PV life cycle in order to improve system performance.
During the selection stage, there are two factors in determining system components – namely vendors and products. Vendor selection is as important as product selection. Because the relationship will be a lasting one that stretches over two decades, it is not unlike choosing a lifetime partner.
For this reason, in order to choose wisely, it is important to have specific vendor selection criteria.
Some characteristics that typify a potentially good vendor include: holding a leading market position, a reputation for being trustworthy and reliable, a stable financial model, bankability, a strong and experienced management team, and comprehensive pre- and post-sales services, including ongoing support.
To dive deeper into a few of these characteristics, a bankable company should have a proven track record with numerous banks and financial institutions.
Worthwhile services that should be part of the offering should include: training and tools, project design, LCOE and ROI analysis, PV simulation and comparative system analysis, project design validation, installation validation checklist, remote and on-site installation support, remote commissioning, automatic commissioning reports, and performance monitoring that offers fleet management, pinpointed automatic alerts, site comparisons, fault detection, and executive reporting.
It is also important to take into account service and support, such as a rapid RMA process and technical support centers. These services are key, not only to the success of the relationship, but also to the operation of the PV system.
In addition to screening the vendor, it is important to carefully review and evaluate the products.
One of the most important components when selecting a PV system is the inverter, which influences 30 per cent of the system costs, completely manages system production, and controls O&M expenses.
As such, the inverter, despite accounting for only 10 per cent of the actual system cost, is critical for the long-term financial performance of a PV.
This is where product quality, durability, and reliability are especially important. Some key indicators of a product’s track record are the amount of installations around the world, operational hours, product failure rates, diverse climate record, and RMA rates.
The quality of a product is determined by its design, components, and its manufacturing. A high-quality manufacturer should have component screening and quality assurance procedures in place.
There should be multiple controls throughout the production processes, which include ongoing testing for quality assurance. Full quality control should be performed on all production lines, including accelerated lifetime testing and root cause analysis on all product failures.
These processes help ensure high-quality, long-lasting products. In addition to inquiring about the manufacturing process, third-parties can ensure that products comply with applicable regulatory requirements, such as safety regulations, electromagnetic compatibility standards, and grid compliance codes.
Product reliability refers to a product performing consistently throughout its lifetime.
A reliable product is one that has a reliability process embedded into all stages of its design and production. At the product design stage, there needs to be full review of the mission profile, design requirements, component selection, and design verification with accelerated life tests.
The manufacturing should be automated to decrease human error and should include an audited quality control process. Following manufacturing is the testing stage, in which fully integrated testing of product parameters and functionality should be performed.
Finally, if any failures are registered, a full analysis should be conducted to reveal the root cause. Any information gained from the root cause analysis should be adapted to refine and improve product design and reliability.
While often considered a synonym for product reliability, product durability refers to a product’s capacity to withstand harsh environmental conditions.
Since PV is often installed in tough environments, all equipment should be robust enough to function under tough conditions such as wide temperature ranges, humidity, dust, rain, and ammonia.
Not only are there ratings such as IP65 and IP68, that can indicate a products durability, but longer warranty periods and results of product testing can also reflect this. Dedicated long-term tests running until wear out include, burn-in, thermal cycling, and damp heat testing.
These tests accelerate a product’s lifetime to verify that it meets life expectancy and performance goals.
The next stage, installation, is essential in maximising profits in commercial PV. There are many key parameters that need to be taken into account for correct installation that will improve a systems quality, reliability, and durability.
During site selection, the standard considerations need to be made, such as orientation, inclination, and shading, but possible corrosion is another criterion that needs to be taken into account.
This can refer to both land corrosion or chemical corrosion that may impact equipment functionality. As an example, commercial installations in the agricultural sector are especially susceptible to ammonia corrosion if products are not designed for this kind of environment.
During the design and planning stage of the system, structural load, wind, and grounding, are all important factors to take into consideration. However, one of the most important aspects is the physical installation of the components.
This includes well-planned configurations, securing wiring, correct labeling, sensors, conduit bodies, all the way down to fully closing all connectors. Any missteps in these areas could not only impact a system’s energy production, but also severely damage the system.
For instance, if connectors are not properly closed, then arcs may occur and potentially ignite a fire.
One of the best ways to ensure proper installation is with in-depth training that includes, system basics, technical details, design rules, safety guidelines, and best practices.
Following installation, maintenance is pivotal in ensuring that a PV system continues to produce at its highest possible level, despite aging. Because life is unpredictable, it is important to plan for the unexpected.
A system with a 25-year lifetime will most likely be impacted by aging mismatch, unpredictable environmental and obstruction changes (e.g. antennas being erected), and defective modules. A few ways to prepare for this is at the product selection stage.
Product warranties reflect a company’s confidence in the quality, reliability, and durability of its product. Products that have a longer warranty or easily extendable warranties can help increase the lifetime of a commercial PV system.
A few other considerations such as selecting low-cost hardware replacements for out-of-warranty products and identifying ways to minimise expensive inventory stock, by using forward compatibility equipment that also provide design flexibility.
Preventative maintenance is a significant and expensive part of maintenance activity; however, it is necessary in order to prevent larger losses.
The activities included in preventative maintenance include general site annual inspection, detailed visual inspection, DC & AC electrical testing, thermal imaging, IV curve testing, and mechanical inspections.
However, with strategic PV asset management tools, preventative maintenance can become more cost-effective and time efficient.
Tools that can improve the longevity of PV systems, while also making O&M more efficient, should include online fleet management, automatic module-level alerts on system issues, remote troubleshooting, and performance, consumption, and export monitoring.
By using such PV asset management tools, the quality, durability, and reliability of a PV system can be extended throughout a commercial PV system’s lifetime.
While not directly related, it is important to note how safety issues can impact commercial PV systems.
This is because safety concerns can sometimes prevent commercial PV systems from being implemented. Some of the safety concerns originate from these buildings often having roofing material that is flammable, made of bitumen or expanded polystyrene material.
Intensifying this concern is the fact that commercial buildings are high-value assets and in the event of a fire, property loss and business interruptions can be costly.
Another impediment is that some insurance companies may not extend coverage in the event that PV systems do not provide proper safety for firefighters and the assets themselves.
To address these safety concerns, high-quality systems with enhanced safety features can be installed. Safety requirements vary from region to region so local guidelines should always be followed.
One of the highest safety standards include reducing DC voltage to safe levels in modules and DC string wires when the inverter is turned off, or when the AC breaker is disconnected.
In terms of arcs, high safety standards are met when inverters and panels can be shut down when exposed to extremely high temperatures or electric arcs.
By employing enhanced safety features, commercial PV systems benefit from advanced technology that improve their quality and even longevity.
While it is common to consider quality, durability, and reliability at the early stages of deploying a commercial PV system, these qualities need to be actively designed into every stage of its life cycle.
By considering the impact that each stage has on the longevity of a commercial PV system, the industry can benefit from more profitable systems and from improved positioning in the energy market.
Lior Handelsman founded SolarEdge in 2006 and currently serves as SolarEdge’s Vice President, Marketing and Product Strategy where he is responsible for SolarEdge’s marketing activities, product management and business development.