Looking To Drive Down Costs? Seek More PV Efficiency In 1,500 V Installations


The greatest known energy source is readily available for unbridled consumption. For generations, some of the greatest minds in engineering and the sciences have sought to effectively harness the power of the sun. As advancements in photovoltaics have grown leaps and bounds in the last several years, at Shoals, we have focused on developing the 1,500 V combiner box as one of the next steps toward ensuring peak functionality and lower installation costs.

The move to 1,500 V allows for 50% longer strings, creating a system that requires one-third of the combiner boxes and cable. It also enables inverter manufacturers to increase rated output power significantly; both of these reduce installed cost. The complete adoption of 1,500 V systems by the industry will happen over time, but all signs point to that time being sooner rather than later. Raising the overall voltage of the system lowers costs from a system standpoint. This holistic approach to system design is another key component in the push for lower system cost.
PV installations are adopting 1,500 V products to help push the installation costs lower. At the close of 2014, utility-scale installed costs varied from over $2.00/W to approximately $1.40/W; as early as 2017, industry executives are predicting that installed costs will be below $1.00/W. The long-term road map for continuous improvement of installed costs requires innovation at all levels. The best frontier for advancement is in the balance of systems (BOS) products.

While the majority of investment funding is flowing into micro-inverter, power optimizing and racking technologies, combiner boxes and wire harnessing are being largely ignored. The reasons for this lack of research and investment funding are obvious, but it fails to recognize an essential and immutable component of a PV installation.

Industry analysts estimate that module costs have fallen by over 70% over the last four years. Inverter costs have dropped over 50%. But, electrical BOS costs have fallen by only 10%. Part of the reason for this is obvious: Electrical BOS components have fewer inputs that can be dramatically reduced in cost while maintaining the integrity of the product. The other reasons, however, are less obvious.

The market is slow to adapt to the potential benefits of forward-thinking electrical BOS for fear of revolt from installers. Many subcontracting installers are reticent to concede control of the installation practices due to a fear of the unknown. But slowly, the industry is adapting. The global commodities market makes reducing cabling and combiner costs challenging but nowhere near impossible.

We feel that continued adaptation of one of the essential workings of the field will help to drive costs below that $1.00/W threshold. Already, the 1,500 V combiner box is helping several of our customers globally while continuing to gain traction.

The next couple of years are crucial to the lasting success of the utility-scale PV market. Despite the fact that most analysts and researchers are claiming that rooftop solar is the future of the market, Shoals is steadfast in its support of larger PV installations. With the across-the-board reduction in costs, utility-scale fields will continue to be attractive to both investors and power consumers.
The further improvement in inverter technology and cost, coupled with our innovative electrical BOS, will help lead the way toward long-term sustainability for utility-grade solar. Although we fully support all forms of solar installations, analysts are less bullish than we are on utility-grade solar.

1,500 V is just the next step; continued innovation will help streamline the installation process and reduce the costs of the fields. Component costs are one thing, but viewing the system holistically is crucial for long-term success. Although the individual cost of a 1,500 V combiner box may be slightly higher than the individual cost of a 1,000 V combiner box, it is lower on a cost-per-watt basis.

Cost per watt is the driving force. As installed prices drop, the market will continue to increase the demand for solar. We hope to do our part to help shepherd the industry toward more efficient and cost-effective PV systems.

Peter J. Maros is executive director of Shoals Technologies Group.

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