What’s the Best Way to Prevent Costly Solar Power Generation Failures?
A beautiful thing about solar power generation is the relative simplicity; it requires no moving parts or external inputs other than sunlight. Therefore, it’s logical to conclude a problem within the multitudes of PV modules – exposed to stresses like hail, high winds, and snow loads – would be the most common cause of system failures. However, in reality, 60% of all downtime is caused by parts of the DC Distribution system representing less than 5% of the total project cost.
A DC Distribution system consists of a series of components responsible for transferring direct current power generated by each PV module to the inverters that switch it to alternating current for the electrical grid. One interruption in this chain and a portion, or all, of the facility goes down.
Exploring the Problem
The root cause of DC Distribution problems is the sheer number of connections required to build out a commercial or utility scale solar installation. It takes between 1,667 and 2,500 modules to produce just one Megawatt (MW) of electricity. Utility projects can range anywhere from 20 to over 500 MW, resulting in millions of connections. At each termination the proper parts, process, and experience are required to ensure reliability.
It takes up to 2,500 PV modules to produce one MW of electricity.
Real-world challenges make consistent execution more difficult for any project, like supply chain delays, skilled labor shortages, and tight timelines.
Critical safety issues are often caused by adaptations made in the field to keep projects on schedule. Building a DC Distribution system requires a wide range of products including: cable connectors, cable management parts, power lugs, grounding, and labeling. Commonly, these components are referred to as the Electrical Balance of System(EBOS). Each EBOS category represents a small line item on the total budget, yet accounts for a huge number of the total pieces needed to complete the project.
Cable management is a big part of solar EBOS.
Careful procurement of EBOS components ensures crews have the proper product solutions available. It’s not just about avoiding headaches; reducing the need for improvisation improves quality. According to the Solargrade PV Health Report, “Installation issues increase when specified equipment is unavailable.” Sourcing these products through fewer suppliers is a savvy way to simplify the overall project, ensure compatibility, and avoid improvisations.
As with any rapidly growing industry, it can be difficult to find enough skilled labor to build large scale solar installations. Wire management problems are the second most common safety issue, and typically stem from installer error, not defective equipment. Thoughtful equipment choice can proactively improve project quality, either through “process design” to help eliminate errors from undertrained technicians or planning for intentional component cross-compatibility to guarantee proper connections even with last minute substitutions. Acknowledging installation teams will be under pressure and selecting easy to use cable management solutions can pay future dividends through greater system reliability.
Long Term Considerations
While the group building a new solar farm may have limited responsibility to warranty the work, depending on contract arrangements, the expected productive life of 25+ years means that long-term system reliability should be a priority for asset owners.
Selecting components made with materials intended for intense UV, high heat, humidity, and cold applications is critical for reliability, given the environmental exposure experienced by solar arrays. It can be hard to visually differentiate between basic and harsh environment versions of some components, so it’s important to double-check product material spec and warranty information.
Investing in better solutions up front is the smart move, otherwise money saved during construction can be quickly dwarfed by future maintenance costs.
This Nylon 612 Cable Tie looks nearly identical to cheaper options today, but it will be a different story in five years.
Should you plan to purchase or sell an existing project, it’s important to remember Clean Energy Associates advice, “Successful solar project acquisition hinges on evaluating the critical technology and engineering choices that have already been made, that will determine the project’s viability and performance. Making sure that a project was done properly the first time can avoid costly and unexpected issues down the road.”
To learn more about DC Distribution components and solutions connect with a Panduit Renewable Energy expert.
Sources: Solargrade - PV Health Report - The-SolarGrade-PV-Health-Report_First-Edition.pdf
Clean Energy Advocates – Top 10 PV Rooftop Safety Risks - Download CEA's Solar Rooftop Safety Report — Clean Energy Associates
