Pros and Cons of Pre-Assembled Solutions for Solar Farms

Enhancing an aged electric grid to accommodate 21^st century energy demands is top of mind for many countries’ governments, and the United States is no exception. The U.S. push toward increased domestic manufacturing, energy independence, and the projected massive investments into electrification (including solar) has led to the construction of utility-grade, industrial, and residential solar farms. However, these large-scale solar projects are running into two primary issues affecting job execution: unpredictable weather (rain, hail, wind, snow, and excessive heat) and the lack of skilled labor (Photo 1).

Photo 1. Two main issues (unpredictable weather and lack of skilled labor) affect construction or large-scale solar farms, such as this one located in Joshua Tree, Calif. — **Photo 1.** Two main issues (unpredictable weather and lack of skilled labor) affect construction or large-scale solar farms, such as this one located in Joshua Tree, Calif.

Unfortunately, these workforce challenges have come at an inopportune time, as solar farm projects are becoming larger and more complex, and, as a result, are requiring more skilled labor than ever before. This creates a vicious cycle. When these challenges are significant enough, projects run behind and put electrical contractors at risk of liquidated assets that erode profit margins. So, how can solar developers and contractors mitigate the unpredictability of Mother Nature and staffing shortages, particularly on large-scale solar projects? Consider pre-assembled solutions.

Manual mishaps and a heated labor force

Pretend it’s 115°F outside (if you spent any time in Arizona this summer, you don’t have to imagine). Workers are outside on the job trying to crimp connectors, assemble combiner boxes, and maneuver large cable reels. Cell phones are so hot they are turning off, and powered equipment is overheating. Given the excessive heat, crews working in pairs can only work in 10-minute increments — 10 minutes on and 10 minutes off in the shade to ensure they don’t overheat (Photo 2). Beyond the 50% productivity loss, these conditions also mean mistakes are more likely to be made — e.g., wire is stripped incorrectly to conductors, a wrong reel is pulled, or the high temperature impacts torque settings on wires, which causes an incorrect torque for connectors.

Photo 2. One of the greatest challenges when it comes to solar farm installations is working in the elements. On a large-scale solar farm, such as this one located in the California desert, crews may only work in short increments due to the excessive heat. — **Photo 2.** One of the greatest challenges when it comes to solar farm installations is working in the elements. On a large-scale solar farm, such as this one located in the California desert, crews may only work in short increments due to the excessive heat.

Heat aside, hand tools used in the field are often not being calibrated consistently, and they can wear down quickly. Manual tools also lend themselves to error, such as a torque tool being too tight, breaking a seal, and letting moisture into the cables. Pre-assembled solutions take the time-consuming and highly critical terminations out of the field, helping to reduce the risk of electrical failures.

If those challenges weren’t enough, finding a skilled labor force to do this work in such conditions is a challenge. While the workers on these large-scale solar farm projects can have high earning potential compared to the industry average, these long, hot days in the field are demanding. By contrast, pre-assembled solutions can decrease the number of skilled professionals needed on a job site because the work was already completed in a warehouse — not out in the field — and shipped directly to the site for faster roll-out.

Benefits of work done in warehouses

Bringing labor out of the field and into the controlled environment of a warehouse helps ensure several things:

More time on prep and less time in the field. Utilizing solutions like pre-terminated jumpers and pre-loaded feeder cables helps reduce on-site installation time. This can eliminate potential downtime due to weather and improve the time to completion.

Material quality and meeting manufacturer requirements to limit liability. Most things are going to be incrementally easier to do in a clean and temperature-controlled environment. Using connectors is just one example. In warehouses, workers have high-tech installation equipment to assist with wire pulling, cutting, stripping, terminating, and packaging; that equipment is inspected and calibrated regularly, along with regular quality control checks to help ensure that processes and specific build instructions are being followed, and materials are clear of dust or dirt. In most cases, these are problems that won’t come to light for a few years after the heat cycles back off and expose the failures. One prime example of this would be in the locking of solar connectors. An electric connection can be made, but a physical connection of the equipment is not made if the lock doesn’t make an audible click. In this case, the connection is not seated and is likely to have issues in the future. Another example is solar connector housings that can keep moisture out of the electrical connection. If the housings are not torqued to the manufacturer’s specifications, there is an increased chance of moisture ingress to the connector, which also adds to the potential for failures of that connector in the future. In a facility, wire can be pre-terminated, cut to length, labeled, and then terminated so that it can be an easy plug-and-play solution on site.No temperature limitations. You can’t pull cable when it’s too cold, and when cutting cable, cutting to the exact length is a greater challenge when it is being done on site. Working in a warehouse, there typically isn’t lost productivity due to weather-related breaks, and materials can be stored at specified temperatures when applicable.

In a real-world example, a customer compared two job sites — one that utilized off-site pre-assembly services and the other that conducted a traditional on-site job installation. By leveraging pre-assembled solutions, the customer achieved net savings of 30% and completed the pre-assembled portion of work 60 days ahead of schedule.

Pre-assembled pros and cons

While pre-assembled solutions make sense for several reasons, this approach does take more time upfront. Dialing in engineered final product drawings to match the engineered site plans can require multiple reviews between parties, as well as first articles — all to ensure that pre-assembled solutions meet construction design requirements. While it may be faster to simply order bulk materials, the gain with pre-assembled solutions is in the labor savings and quality of the project. Using pre-assembled solutions, contractors can reduce their labor in the field significantly.

According to a Dodge Data & Analytics SmartMarket report, 90% of contractors say they achieve improved productivity, improved quality, and increased schedule certainty compared with traditional construction methods. Additionally, given the service model of pre-assembled solutions, the costs may be higher upfront, but when factoring in the entire expense of the project with labor included, it can ultimately end up costing less. Operations and maintenance costs can also be reduced.

If your organization is looking to move to pre-assembled solutions, consider engaging with partners early on, and be sure they will stand behind their installations, offer engineering to make the solutions as efficient as possible, communicate about changes along the way, and have a solid QA/QC process in place.

While many of the same physical material components are the same if installed in the field or constructed on pre-assembled solutions, the devil is in the details. This approach is not completely about the products used but rather the process needed to execute a successful project on time and on budget. That element alone can be a distinct competitive advantage.

Sean R. Nacey is senior vice president and general manager, U.S. Construction and Energy Solutions, Wesco.