Bulgaria's gross electricity production rose by 4.2% year-on-year in August, while electricity supply decreased by an annual 3.4%, the National Statistical Institute (NSI) said on Tuesday. On a monthly comparison basis, Bulgaria's power output grew by 4.8% to 3,953 GWh in August, the NSI said in a statement. Electricity supply added 1.9% month-on-month in August, reaching 2,579 GWh.