The power management in the capital has changed hands many times. The Delhi State Electricity Board (DSEB) set up in 1951 was succeeded by the Delhi Electric Supply Undertaking (DESU) in 1958. The Delhi Vidyut Board (DVB) took over power management in 1997 which is now in the hands of Reliance Energy Limited (REL) and Delhi Electricity Regulatory Commission (DERC) which regulates the tariff structure and other regulatory issues.