The Mobility House to optimize 2.5 GWh of colocated battery storage in Bulgaria

Electrohold Trade, the electricity trading division of Bulgaria’s energy and insurance group Eurohold, will use aggregation and trading software from Germany’s The Mobility House to optimize its portfolio of colocated battery energy storage systems (BESS).

The 2.5 GWh portfolio comprises assets with a two-hour storage duration, spread across a 100 km area. The projects are at various stages of development. According to The Mobility House, the battery projects are in advanced development, with full commercialization expected from Q4 2025. Further ramp-up is planned for early 2026.

All BESS installations are hybridized with onsite solar PV, sharing the same grid connection. This colocated configuration demands more sophisticated optimization algorithms than standalone systems.

“This is far more complex than basic intraday arbitrage — which is often the sole revenue stream for standalone storage systems,” Marcus Fendt, managing director at The Mobility House, told ESS News. “In a colocated setup, we must factor in variables like solar generation forecasts, grid imbalance levels, and trading opportunities.”

Fendt added that The Mobility House has been an early pioneer in stacking multiple applications for BESS, beginning in 2018. The company began optimizing colocated assets last year, which helped it secure Electrohold’s tender.

“For the Bulgarian fleet, we’ll combine intraday continuous trading, MFRR (manual frequency restoration reserve), imbalance market participation, and benchmark our performance against an index,” Fendt said. “Our algorithms also account for battery aging, ensuring optimal usage while protecting asset longevity.”

The Mobility House currently manages 120 MW of operational BESS assets, with another 180 MW in development across Germany, France, and the Netherlands. The addition of the Bulgarian portfolio will significantly expand its optimization business.

“Bulgaria offers a unique market compared to Germany,” said Fendt. “Without a subsidy scheme, PV projects are typically deployed with integrated storage. This trend is accelerated by the declining cost of utility-scale BESS, now under $100/kWh in Europe.”

Bulgaria is rapidly emerging as a key market for energy storage in Europe. The country recently announced the results of its first standalone energy storage tender, awarding 10 GWh — far exceeding the original 3 GWh target. In November 2024, authorities allocated 1.17 GW of storage capacity in the country’s first renewable energy auction.