Monthly Archives: April 2011

UL Approval for Micro Inverters

Enecsys solar PV micro inverter becomes the world’s first without electrolytic capacitors to gain U. S. certification to UL1741 standard

Cambridge, U. K., January 8, 2011: Enecsys Limited, a solar PV micro inverter company, has announced UL1741 certification for its products. The patented design of the Enecsys micro inverter uses a rugged topology that eliminates electrolytic capacitors and opto-couplers, components that limit operating life and compromise reliability. Enecsys 240W micro inverters are the first micro inverters without electrolytic capacitors to achieve UL1741 certification. The same product is also certified for use in Europe, making Enecsys is the first company to introduce a truly global solar PV micro inverter. The inverter has an operating life expectancy of greater than 25 years, matching that of solar PV modules. This transforms the economic model of solar PV systems through greatly enhanced system reliability, energy harvest, ease of installation and improved system safety.

Solar PV systems based on micro inverters harvest from 5 to 20% more energy over the life of the system, compared to traditional string inverter based systems. In a micro-inverter based system Maximum Power Point Tracking (MPPT) is performed on each solar module and thus maximizing energy harvest even under partial shading, module mismatch or obstructions from leaves or debris. Systems are simpler to design and install and are safer because the high-voltage DC present in conventional solar PV installations is not present. No string inverter is needed because the DC output of each solar module is converted to AC using a micro-inverter mounted on the rack behind each module. This eliminates the central point-of-failure and the primary failure mechanism found in traditional inverters systems and micro inverters currently available in the market.

The reliability of Enecsys micro inverters has been verified using HALT, HASS and accelerated life tests to IEC61215, the same methodology used to test solar PV modules. The micro-inverters maintain full performance from -40 degrees C to +85 degrees C, ensuring efficient operation in real-world conditions. The Enecsys Wireless Monitoring System provides real time performance information for each solar module in order to maintain the high performance of the solar PV system throughout the operating lifetime.

The Enecsys micro inverter is designed to operate in both North American (60Hz) and European (50Hz) electricity grid systems. The micro inverters are safety and EMC evaluated to EN 62109, UL1741, TUV and CE. Country-specific requirements, including VDE V 0126-1: 2006 compliance, are achieved through the use of specific Enecsys installation products.