Bulgaria's Ministry of Economy has ordered the Electricity System Operator, ESO, to stop imposing restrictions on the production of energy by wind farms and photovoltaic plants on a regular basis.

Bulgaria's Ministry of Economy, Energy and Tourism (MIET) requires ESO to justify each restriction by publishing proof on its website, according to reports of Capital daily.

The regular capacity restrictions on renewable energy plants were explained with the imbalance between electricity production and consumption.

The restrictions concerned 40% of the grid-connected renewable capacity.

To defend the step, ESO noted that in Q1, 2013 Bulgaria's electricity exports had decreased by 22. 5 % on the year, while domestic consumption of electricity had fallen by 13.07%.

The restrictions caused the Bulgarian Photovoltaic Association (BPVA) to issue a number of letters of protest, claiming that the measures had been illegal.

"The spate of accusations against green energy seeks to justify the series of wrong political decisions which pushed Bulgaria's energy sector from  deficit in January 2010, when electricity exports were stopped, to overproduction in March-April 2013" the BPVA argued.

Meanwhile, caretaker Energy Minister Asen Vasilev suggested that owners of renewable energy plants had declared that the capacities had functioned 32 hours a day but he refused to name concrete offenders.

Capital Daily argues that the restrictions were "nearly illegal" as Bulgaria is under an obligation to purchase green energy.

Stressing that the ESO never explained why the cap had been set at 40%, the newspaper suggests that the restrictions were imposed not to remedy imbalances but to reduce green energy costs at the expense of other power plants.

Capital Daily points out that a number of owners of renewable energy power plants are suing ESO because the 40% capacity restrictions imposed on a total of 20 days so far, together with the grid access fee, have driven them to bankruptcy.