Storage Deals in One Day Span Megawatt Trading Batteries to Seven-Day Compressed Air

Vattenfall signed long-term marketing agreements for four battery energy storage systems in Germany totaling 285 MW, three of them already under construction, that will trade in wholesale and balancing markets. The same day, the first phase of the MESH project was set out as a 300 MW/55.2 GWh compressed-air energy storage plant capable of operating at full power for more than seven days. Vattenfall's portfolio is measured in megawatts for wholesale and balancing-market trading, while MESH is measured in gigawatt-hours for multi-day discharge.

Telecom infrastructure anchored two separate storage commitments. Replus agreed to make 1.5 GWh of dedicated battery energy storage system (BESS) production capacity available over two years to support telecom sites. NTT Anode Energy, JERA Cross and NTT Docomo will begin a demonstration project on October 1 combining solar power plants, grid-connected battery storage and NTT Docomo telecom buildings in western Japan.

On the manufacturing side, General Motors and LG Energy Solution plan to invest USD 1 billion to convert their battery manufacturing facility into the world's first plant dedicated to mass-producing prismatic lithium manganese-rich cells.

For one supplier the shift has already landed in the accounts: energy storage generated 78.3% of Hoymiles' first-half 2026 revenue.

The applications do not share a single duty. A plant built to run for more than seven days at full power serves bulk energy shifting, while a 285 MW portfolio cleared into balancing markets serves fast response. If multi-day capacity on the MESH scale reaches commercial operation, it would compete for a different role than the megawatt batteries now trading power.

If telecom operators standardize on dedicated battery capacity, equipment makers gain a buyer outside the grid and vehicle markets. Replus has committed 1.5 GWh over two years to that single end use, and the western Japan demonstration pairs batteries directly with telecom buildings and solar plants.

The nearest observable marker is the demonstration's start on October 1. Three of Vattenfall's four German systems are already under construction, and the USD 1 billion conversion plan targets the world's first plant dedicated to mass-producing its cell chemistry. A revenue base like the 78.3% share Hoymiles reported for the first half of 2026 ties a manufacturer's results directly to how fast these deployments arrive.