Wait…. What? Did it fail already? Pardon us for being the doomsayer here but the we always knew that would never work anyway. High frequency string inverters have always been like the brightest student in the classroom, but put them into gym class and 5 times out of ten, they are likely to leave the class howling and bruised.
The Indian rural electrical grid is a whirlpool of problems, most affecting the revenue of the telecom BTS companies. In turn the companies turn to their rusty old servant, the DG Set generator who has stood by them for generations now, but frankly it is a bit too high maintenance for my liking. In hindsight, the problem of reducing the Diesel was never going to be solved by using grid tied String inverters and the Telcos have now finally come to terms with that.
The rationale behind installing Grid tied String inverters was that Energy generation was being affected negatively by using MPPT charge controllers. No power could be exported if the battery was already charged. String inverter arrived on the scene to change all that. No more trouble with exporting power anymore. But err.. did it really provide a robust solution?
The trouble with the grid tied string inverters started with the fact that rural electrical grids supplied the majority of their power during the night time and the daytime power was diverted more towards the industries. The grid was unstable with voltages dipping as low as 110 V on a 230 V line. Problems with the phases, phase rotation, phase dropping, frequency out of range are just some of the problems that the string inverter battled against.
It’s inability to reduce the diesel consumption, ensure maximum generation and general shutting off during adverse grid conditions has made it the Arsene Wenger of Solar inverters. It’s time to seek new pastures now. Fare thee well from the telecom industry.