Bulgaria has begun construction of a 300 MWh battery energy-storage facility in Tvarditsa, marking the first stage of a broader investment programme worth more than €350 million. The programme includes three battery projects with a combined storage capacity of more than 2.3 GWh, aimed at improving the country’s ability to integrate rapidly expanding renewable generation.
The Tvarditsa facility is being developed by Asarel-Trade and Power Profit using Tesla technology. The project will deploy 80 Tesla Megapack 2XL units together with 20 transformers rated at 4.4 MVA. The system is designed to provide approximately five hours of discharge capability, allowing stored electricity to be supplied to the grid when needed.
Battery investment has accelerated across Bulgaria as the rapid growth of solar and wind generation increasingly affects the country’s intraday electricity balance. Large-scale storage can absorb surplus renewable power during periods of high production and release it later when generation falls or electricity demand increases.
The expansion of storage could help reduce balancing requirements and ease some of the increasingly sharp wholesale electricity-price fluctuations associated with higher renewable penetration. Batteries can also provide additional flexibility during periods of rapid changes in supply and demand.
Once all three projects are completed, the programme is expected to provide more than 2,300 MWh of energy storage capacity. This would represent a significant expansion of Bulgaria’s ability to shift electricity across different periods of the day.
At the same time, Bulgaria is evaluating additional battery storage, pumped-storage hydropower and new generation capacity as part of efforts to modernise its electricity system and provide greater flexibility for renewable-energy development.
The emerging battery fleet could also strengthen Bulgaria’s role as an electricity-trading hub in Southeast Europe. This is particularly important during periods when strong solar output produces large daytime surpluses followed by steep increases in demand and declining renewable generation in the evening.
For investors, the rapid development of large-scale batteries signals a broader shift in Bulgaria’s power market, with energy storage increasingly becoming a standalone component of electricity infrastructure, rather than simply a supporting technology for renewable generation.
