UL 1741 was revised in September to incorporate Supplement SA, says Intertek. “It is intended to validate compliance with grid interactive functions that are not covered in IEEE 1547-2003. The supplement aims to define the evaluation criteria for utility interactive inverters with grid support functions that are rated and specified as ‘grid support utility interactive inverters.’ This new nomenclature is intended to differentiate these products from utility interactive inverters.”
The UL 1741 SA specifies the test methods needed to build the foundation enabling DG devices to stay online and adapt their output and overall behavior to stabilize the grid during abnormal operation rather than simply disconnecting.
By meeting the advanced inverter requirements, SolarEdge’s optimized inverters enable utilities to build in higher levels of PV solar generation. SolarEdge inverters that meet this requirement will be installed with the label of “Grid Support Utility Interactive Inverter” and will provide smart inverter features to residential PV system owners.
“The SolarEdge single-phase inverters are the first inverters we have confirmed to meet the UL 1741 SA draft requirements,” says Sunny Rai, Vice President of Renewable Energy at Intertek. UL launched testing for the new draft in September.
“Meeting this smart inverter requirement continues our leadership in developing next generation technology and in advancing PV system’s grid interaction to further the implementation and integration of solar energy,” says Handelsman.
SolarEdge’s smart inverters now offer advanced inverter functions to the mainland US Market and have already brought functionality similar to Rule 21 to markets such as Germany, Italy, England, Australia, Hawaii, and Japan.
The State of California has announced that inverters installed in the state will be required to comply with the Rule 21 grid interconnection requirements within one year of publication of the UL 1741 SA. Other states are considering adopting similar installation requirements, especially in areas with high levels of DG and solar penetration.
“With some of the highest PV penetration in the United States, Hawaii is increasingly looking to smart inverters for grid management solutions,” said Research Engineer Andy Hoke of the Energy Department’s National Renewable Energy Laboratory (NREL). “To meet this growing challenge, NREL worked with SolarEdge to test their products as part of Hawaiian Electric’s advanced inverter testing program.”