June 1, 2020
By Michael Shulman, Principal Engineer, Lighting
Whether you’re interested in reducing your carbon footprint, saving money or embracing newer technologies, there’s a place in your life or at your facility for solar panels, batteries and LED luminaires. Now, you can have them all together in one safety-certified package.
UL has just published a new Outline of Investigation to guide the evaluation of lighting systems that include photovoltaic (PV) modules for gathering energy, batteries for storing that energy and LED luminaires to illuminate nearby pathways, parks, parking areas and roadways. This is a case of converging technologies in which items that were previously for novelty use (primarily limited to decorative pathway stake lights) now provide viable and practical lighting systems suitable for a wide variety of applications.
For remote locations far from an existing electrical utility connection, these systems provide an opportunity to illuminate areas with very little infrastructure or maintenance cost. And where a utility connection is available, they are able to tap into that only as needed to supplement solar energy when light harvesting during the day or battery storage capacity is limited. The reliability and longevity of PV modules and LED technology, both of which have reached a useful stage of maturity, suggest that only periodic battery replacement is likely to be needed for a well-designed system.
PV-powered luminaire systems of this size and power capacity warrant assessment for safety risks, both at the design stage and for production purposes. Since the basic requirements for the key system components are well-established, the focus of UL 8801 is on bringing these components together in a way that helps ensure the power flow between them aligns with their individual known capabilities, system-level cumulative risks (such as heat generation) are properly evaluated, and individual component failure modes are adequately managed by the system control features.
In addition, UL 8801 includes an optional performance annex that establishes minimum benchmarks for sustaining light output over a period of time and to verify manufacturers’ claims for such performance. This performance annex is mostly targeted towards PV-powered luminaire systems intended for street, park and parking applications where certain minimum lighting levels may be required for safety or security purposes.
A key challenge to certifying these systems is scaling the investigation program to match the level of hazard. Because the batteries have many hours during daylight to charge, they do not require high levels of current flow. So appropriately sized PV modules will typically be smaller than the standard 65-by-39 inch (2 x 1.2 m) PV panels used for rooftop installations or solar arrays intended to generate electricity for general use. At present, few of these smaller panels have been certified as compliant with IEC/UL 61730, the Standard for PV Module Safety Qualification. UL is developing a streamlined investigation program for UL 8801 applications, maintaining the principles of UL 61730 while proportionately reducing the time and cost burdens to match the needs for these systems.
As an Outline of Investigation, UL 8801 reflects the requirements for UL’s newly launched certification program for PV-powered luminaire systems (certification category code IFPV). Over the course of the next year, as investigation experiences accumulate and feedback is received from interested parties, UL expects to issue a new edition of the outline with updates and revisions. From there, it will likely move along the path towards an ANSI standard in which the technical content will be managed through the consensus-development process employing a diverse group of stakeholders.
UL is excited to offer this new outline and certification program to a world looking for new ways to address the challenges of climate change and thirsty for innovative solutions that are efficient to install and operate. The safe and widespread utilization of solar energy can have widespread positive impacts on many parts of globe, including bringing benefits of electrical illumination to remote and underdeveloped areas. UL 8801 is an important step to encourage the safe and effective deployment of these technologies.