Bulgaria's power export capacity stands at 1,700 megawatts (MW) but exports rarely exceeded 1,350 MW in the past months, the country's Electricity System Operator (ESO) said.
It provided no other figures.
Power exports have dropped due to lower electricity consumption in southeastern Europe and larger amounts of power produced by hydropower plants compared with 2011, ESO said in a statement.
Bulgaria's electricity output balance allows maintaining exports at last year's levels, it added.
In June, ESO, as cited by state-run Bulgarian News Agency, announced it suffered 27 million levs ($17.2 million/13.8 million euro) losses for the first four months of the year due to reduced electricity exports.