petroleum products, fuel, electricity and other sources of energy./ "supply of net electricity and selection of a coordinator of a standard balancing group for the sites of ardino municipality, kardzhali district." "supply of net electricity and selection of a coordinator of a balancing group for the needs of the municipality of ardino, kardzhali district" and includes: supply of electricity for all municipal sites in the municipality, including secondary managers, inclusion of sites in a standard balancing group with coordinator the contractor, providing a service for forecasting consumption, preparation and submission of hourly schedules by the coordinator of the balancing group, responsibility for balancing all activities related to participation in the liberalized electricity market of the contracting authority and bear the costs of imbalances .