Bulgaria& rsquo;s power system has the capacity to hook up only 17 percent of the renewable energy projects announced so far, experts told a hydro energy forum held near the coastal city of Varna last week. Ventsislav Zahov, electricity regimes head at the state-owned system operator ESO, estimated that the network could accommodate up to 1,800 MW of capacities but as many as 11,000 MW in wind and solar parks have been planned so far. Even if only half of this moves from the drawing board into practice, vast backup capacity is needed to secure supplies when winds are low, he explained. Hydro power plants could play the role of filling in for other renewable energy projects but threadbare energy infrastructure is a major obstacle for grid-connection. Before they could go ahead with any grid investments, the national power gird operator NEK and the regional electricity distributors need the nod of the State Energy and Water Regulatory Commission (SEWRC). The watchdog often turns down prop...