NTT Facilities Inc announced that its 1.682MW solar power plant in Tsuchiura City, Ibaraki Prefecture, started power generation Feb 28, 2014.
The power generation system at the plant deals with 1,000V direct-current electricity, contributing to reducing installation cost, increasing the amount of electricity generated and improving the efficiency of the entire system. Compared with the company's 600V direct-current system, the new system enables to reduce the number of strings (series circuits of solar panels) by up to 40% (and, thus, the number of connecting boxes).
Also, the 1,000V direct-current system allows to use larger-capacity PV inverters. For example, in the case of a 2MW solar power plant, it is possible to eliminate one PV inverter by using larger-capacity PV inverters.
Furthermore, the high voltage reduces loss caused by circuits and improves the conversion efficiency of PV inverters. As a result, the overall efficiency of a large-scale solar power generation system possibly increases from about 70% up to 90%, NTT Facilities said.