The European Commission will review a decision of Bulgaria to stop exporting electricity on January 13, an official has said.

The announcement follows Bulgaria's decision to renew exports of electricity as of the small hours of Thursday. 

Exports were halted amid harsh winter conditions in January.

The move to renew them angered some businesses which said it would push up electricity prices on the energy exchange. 

But Florian Ermacora, who heads the European Commission's wholesale energy and gas trade department, says "shutting borders" on the market is not the best solution when power generation is not good enough. 

Bulgarian officials maintain no national energy laws were broken, but the EU Commission indents on checking whether the step violated common rules.

Bulgaria was one of the many countries, including neighbours Greece and Romania, which halted exports to make sure their energy systems would withstand the cold weather. 

"As freezing weather triggered energy shortages across southeast Europe at the start of the year, Bulgaria’s refusal to export power was typical in a region where everyone had to fend for themselves," Bloomberg writes in a fresh report.

"The reaction highlights the European Union’s struggle to break down national barriers for power and gas, integrate markets and bolster energy security as it tries to ease dependence on Russian fuel," it says.