Problem Statement: The solar industry struggles with fire. Historically underreported by the U.S. Fire Administration, fires at solar installations rose 36% from 2017 to 2018, with residential installations representing the majority of fires. Every year, arcing faults are responsible for 30,000 fires in the US, killing and injuring hundreds of people, and causing over $750 million in property damage. It is anticipated that by 2025, 64 photovoltaic (PV) system fires will occur in California alone, resulting in injury and costs projected to exceed $18 million.
PV systems being installed today have no built-in autonomous protection from fires, human injuries, and death caused by DC electrical faults. The PV industry is in dire need of an inexpensive and reliable arc-fault detector that is sensitive enough to pre-detect arc-faults before a fire occurs and robust enough to limit unwanted tripping due random variations in voltage or current.
The Solar Guardian PV Connector (SG) innovatively disconnects electricity by opening the circuit with a spring-actuated slider that activates when the operating temperature of the connector rises above the thermal rating (85-95°C). When the SG detects heat above 85-95°C, it will disconnect the electricity flowing through that panel and take only the connected string of panels offline, protecting the investment, and leaving the remainder of the array to continue producing clean energy.
This product is built on reasonable assumptions formed through a valid technical foundation when Sandia National Laboratories (SNL) contracted us to assist in solving the problem of electrical fires in PV systems.
Unique Value Proposition: The SG is the first connector that pre-detects arcing-faults by opening the circuit and preventing a DC electrical arc-fault from occurring, without nuisance tripping. The eventual cost of $6.25 per SG is affordable, yet profitable, offering an alternative for installers to retrofit current systems and original-equipment-manufacturers to include in new installations.
According to 2021 market research published by the Solar Energy Industries Association , over 270 million PV connectors have been installed, averaging more than 100 connectors/array , which represents a sustainable market with paying customers.
The patented SG outperforms competitors by detecting circumstances that could lead to a fire at the module-level. Competitor solutions detect an arc after it has sparked and damage has occurred, resulting in shutdown of the entire array and lost power generation.
The SG is the first connector to comply with the National Electric Code (NEC) Article 690.11, that requires detection and interruption of arcing faults. We have additional technology and intellectual property with features for automatic notification using wired or wireless applications for installers, homeowners, fire fighters, and maintainers.
Prototype: The SG prototype has evolved into a self-contained electrical connector that monitors for heat above 85-95°C using a spring and a dielectric. A dozen iterations of low-fidelity prototypes have been tested, and critical material failures and thermal trigger points were addressed. We resolved this by working with material suppliers and by adding a retainer that releases at the desired maximum temperature unaffected by diurnal cycling, forcing the electrical connection open.