Croatian energy regulatory agency Hera has issued its first licenses for energy aggregation services to the companies IE Energy and Nano Energies Hrvatska, its public relations officer Blazenka Kostic Curic told Montel last week.

Rijeka-based IE Energy will aggregate around 10 MW of distributed prosumer capacity through its virtual power plant platform with the goal of reaching 100 MW over the coming years, according to its director Zeljko Smitran.

Smitran told Montel in a telephone interview on Friday that the company is constructing a battery energy storage system with 22 MWh of capacity in the coastal city of Sibenik and that it should be operational in Q1 2023.

“When this investment is completed, we will be able to offer balancing services to the TSO Hops,” he added.

Virtual power plants or aggregators, as they are defined in Croatia’s electricity market law, provide a new mode of system balancing that connects decentralised power sources, consumers and storage systems, offering end-users the opportunity to participate in the power market.

Hops currently procures a balancing capacity through public tenders for manual frequency restoration reserves (mFRR), and it will soon launch tendering procedures for automatic frequency restoration reserves (aFRR), said Smitran.

The Czech-owned Nano Energies Hrvatska has not provided any information about the capacity it will aggregate. Its country manager, Dominik Maricevic, told Montel that the plan is to build a reliable portfolio of producers, consumers and electricity storage facilities that will primarily contribute to the stability of the power system, but also provide users with additional income.

It is worth mentioning that Croatia already has an independent aggregator, Koer, which signed a balancing service agreement with the TSO in February and will now ask Hera for an energy aggregation licence.

Koer’s director Marko Lasic told Montel on Friday that the company’s existing contracts with flexible power consumers represented over 1% of the Croatian electric power system’s overall consumption. Among these clients is the Holcim cement plant in the Istrian town of Koromacno, which signed a contract with Koer in June, although no information about the capacity being offered has been disclosed.

When Hops signed the balancing agreement with Koer, it told Montel that Koer’s engagement had enlarged the power system’s overall reserve level and the consumption of aggregated grid users could be reduced at Hops' request.

Given that the number of rooftop solar installations is expected to increase in the future, aggregators will become important market players as they can interconnect small producers, energy expert Neven Duic told Montel in an e-mailed statement on Wednesday.

Duic also said that currently there is an opportunity to turn a profit by buying surplus power from prosumers and selling it on the energy exchange, although acknowledging that the available amounts are not yet that significant.