Beijing has approved the planning permit for a power tunnel supporting the Fengtai 500kV transmission and substation project, with construction slated to begin in December and finish in 2028.

The Fengtai 500kV substation, located in the southeastern part of the Lize Financial Business District, will cover about 1.88 hectares with a total floor area exceeding 16,000 square meters. The project involves a total investment of 4.97 billion yuan and will be equipped with two 1,200 MVA transformers, adding 2,400 MVA of substation capacity.

The approved tunnel, serving as supporting infrastructure for the substation's incoming and outgoing lines, will span 8.7 km with 500kV cable lines stretching 35.25 km, making it the world's longest 500kV land cable upon completion.

The project will mark the first demonstration application of domestically produced core materials for 500kV cable insulation and shielding, breaking through key material bottlenecks for ultra-high-voltage cables and achieving technological breakthroughs in ultra-long-distance, high-capacity cable transmission.