The world's first ultra high-voltage DC transmission system (UHVDC) has completed its final testing. It is the first transformer for the new 800 kilovolt (kv) HVDC. HVDC transmission systems normally operate at a standard transmission voltage of 500kv. Siemens has decided to deliver 10 high performance transformers for the Yunnan Guangdong HVDC system, which from mid-2010 onwards will be transmitting 5,000 megawatts of power over a distance of 1,400 km. HVDC solutions form part of siemens environmental portfolio, which generated euro 17 billion in sales for the company last year. To achieve this 60 per cent increase in peak voltage capacity, siemens had to develop a range of entirely new technical solutions for the new 800 kv HVDC transmission system. Siemens has also got order for 10 more HVDC system from Xiangjiaba hydroelectric power plant in southwestern china and shanghai, which will transmit 6,400 MW over a distance of more than 2,000 km.