Summary

The up to 400 volt DC (VDC) power solutions feeding the power interface of ICT/telecom equipment as defined by the ITU-T L.1200 series, are well adapted to the straightforward use of renewable energy or distributed power sources through new simple direct current (DC) nano or micro grids. Recommendation ITU-T L.1205 defines the coupling of local or remote renewable energy into an up to 400 VDC power system without reducing DC performances defined in Recommendation ITU-T L.1202 mainly for efficiency and reliability. The main advantages are saving of fossil fuel (as a source of primary energy consumption), reduction of greenhouse gas (GHG) emissions and increased resilience. Additional site interconnection by a DC grid can even bring more optimization. One other big benefit is that compared to alternating current (AC), with 400 VDC there is no synchronization required between the various inputs, which keeps the architecture simple.