Renalfa IPP puts largest battery facility in Bulgaria into operation

Renalfa IPP has started the commercial operation of its first utility-scale battery energy storage system. The 25 MW – 55 MWh facility in the town of Razlog in southwest Bulgaria is colocated with a 33 MW photovoltaic plant.

Just half a year after the announcement of the deal, one of the first larger battery energy storage systems (BESS) in Eastern and Southeastern Europe launched regular operation in early June. Solarpro Technology designed, installed and integrated the facility with the grid for its parent company Renalfa IPP.

The system with 25 MW in operating power and 55 MWh in capacity is colocated with a solar power plant with a peak capacity of 33 MW. The site is next to the town of Razlog in southwest Bulgaria.

The BESS, connected to the transmission grid run by the Electricity System Operator, is the biggest in the country. It stores energy during the daily peak of photovoltaic output and arbitrage on the electricity market.

Rystad Energy has estimated taht the potential profits for electricity arbitrage with battery storage in Bulgaria are the highest in Europe. The activity involves charging batteries when power prices are low and discharging them during peak demand periods.

Renalfa IPP providing grid services with its Razlog BESS

Electricity trader KER Toki Power, Renalfa’s subsidiary, is in charge of operation and optimization in Razlog. Via its aggregator platform, the system participates in the capacity and balancing markets, providing automatic frequency restoration reserve (aFFR) and manual frequency restoration reserve (mFFR) services to the grid, Renalfa IPP said. Hithium and Kehua have supplied the main components.

It is the start of hybridization of the portfolio of renewables in operation and construction of more than 1 GW, spokesperson for Renalfa IPP Nick Antonov stressed.

Renalfa IPP intends to hybridize its 1 GW portfolio

“We are about to introduce similar solutions in the other wind and PV assets in the region, including Hungary and Romania. The main goal is to fully mitigate the PV profile risk of the generators. In the wider context of the energy transition, this facility demonstrates how advancements in technology are making renewable generation far more useful, dispatchable and flexible to supply and demand,” Antonov added.

One of the projects is Tenevo, for a wind-solar hybrid power plant in Bulgaria with a 250 MW – 500 MWh battery system.

Company has 455 MW in operational assets

Vienna-based developer and independent power producer Renalfa IPP is a joint venture between Renalfa Solarpro Group and the French infrastructure fund manager RGreen Invest. The company said it owns and develops photovoltaic, BESS and wind projects with an overall capacity of 2 GW in Bulgaria, Hungary, North Macedonia and Romania

More than 455 MW is already operational and more than 550 MW is under construction, Renalfa IPP revealed.

When the company signed the deal with Hithium in November, they said it was the largest battery energy storage system (BESS) in implementation in Southeast Europe.

Turkey attracting massive investments in renewable electricity plants with BESS

As for notable investments in the rest of the region that Balkan Green Energy News covers, NGEN is developing a 70 MW battery project in Slovenia. The company said the endeavor is worth EUR 70 million.

Plovdiv-based Vineli Re plans to build a wind and solar park, combined with electricity storage near Dobrich in northeast Bulgaria.

In March, the government in Sofia issued public calls for grants for the installation of renewable energy plants with 1.43 GW in total capacity alongside energy storage of 350 MW in overall operating power.

The biggest BESS unit in Romania came online a few months ago within a wind and solar hybrid project. Sweden-based Monsson installed 6 MW in operating power and a capacity of four hours, translating to 24 MWh, in the first phase. It plans to expand the facility to 216 MWh next year. Notably, domestic company Prime Batteries Technology or PBT manufactured the modular lithium ion batteries.

Greece held two auctions for battery subsidies so far.

However, Turkey is still dwarfing all other Balkan countries in the sector, at least in the number and size of pending projects. The Energy Market Regulatory Authority (EMRA or EPDK) gave priority late in 2022 to hybrid power plant projects that include a matching storage facility in terms of operating power. Late last year, it said it prelicensed 439 projects for 25.6 GW within solar and wind facilities.

Their combined value is estimated at USD 35 billion.