A South African government tender for 2 000 megawatts of emergency power has been challenged in court by one of the companies that lost out, potentially delaying capacity being added to the grid and prolonging an electricity crisis. South Africa's DNG Power wants the High Court to review its disqualification from the tender and prevent the government from signing and implementing agreements with the preferred bidders, court papers seen by Reuters show. The government named the eight preferred bidders last month. Turkey's Karpowership was a major winner, with three of its floating gas power stations among the eight projects chosen…