Grid-Scale Energy Storage Projects Heat Up Globally
Source： eepower
A Texas startup has completed a key test for its long-duration geomechanical energy storage system. Another U.S. company has started shipping its first grid-scale sodium-ion battery systems. Meanwhile, a new project in Europe could transform a decommissioned nuclear plant into a high-capacity battery hub to stabilize renewables in Germany.
These developments follow a year of rapid expansion in the battery storage sector. In 2024, the market grew by 44% and installed 69 GW/161 GWh, with grid-scale systems leading demand. Wood Mackenzie projects that global energy storage will reach 1 TW/3 TWh within the next decade—about seven times today's levels.
Quidnet's geomechanical energy storage design. Image used courtesy of Quidnet Energy
Geomechanical Storage System Passes Long-Duration Test
Texas-based Quidnet Energy verified that its geomechanical energy storage (GES) system held a full 35 MWh charge for six months, and then fully discharged it—demonstrating "no discernible losses." The test was conducted at Quidnet's Houston-area project site, as part of an agreement with local utility CPS Energy.
The system stores energy by pumping water from a surface reservoir into a sealed well drilled into rock formations. The rock acts as a natural pressure vessel, maintaining the water under high pressure. When energy is needed, the well opens to send pressurized water through a turbine to generate electricity.
GES modules range from 1 MW to 10 MW each, with storage durations from tens to hundreds of hours. Quidnet targets applications requiring reliable, dispatchable output, such as data centers’ continuous loads and artificial intelligence.
Germany to Convert Former Nuclear Plant into Huge Battery Hub
EnBW plans to build a 400 MW/800 MWh battery system at the decommissioned Philippsburg nuclear power plant in southern Germany. The project is envisioned as a central storage zone for renewable energy in the region. It will be integrated into the Ultranet high-voltage direct current (HVDC) transmission line, which channels wind power from northern Germany to the southwest.
Once operational, the system could supply the equivalent of one day's electricity demand for 100,000 households, according to EnBW.
The Philippsburg site already hosts a major HVDC substation operated by TransnetBW. Commissioned in November 2024, the substation serves as Ultranet’s southern endpoint and includes a static synchronous compensator to provide reactive power support for grid stability.
EnBW has submitted the project to local authorities and aims for commissioning in late 2027, pending approvals. If built as planned, it would be among Germany's largest battery energy storage installations, marking a significant reuse of existing grid infrastructure for renewable energy integration.
Peak Energy Ships First Sodium-Ion Storage System
Peak Energy has started delivering its GS-1.1 sodium-ion battery system for a large-scale pilot involving nine utilities and independent power producers. The 3.5 MWh system is rated for a four-hour discharge and features a fully passive cooling design.
The Colorado-based company touts its technology as the world's largest battery system using sodium-ion phosphate pyrophosphate chemistry, and the first grid-scale sodium-ion storage deployment in the U.S.
The GS-1.1 offers a 95% DC round-trip efficiency and is designed to operate from -40 to +55°C. According to Peak Energy, GS-1.1's passive cooling architecture can provide annual operational cost savings per gigawatt-hour installed, representing an up to 90% reduction in auxiliary power use. It also reduces battery degradation by 33% over the 20-year lifespan.
Overall, GS-1.1 lowers lifetime costs by around 20% compared to average lithium iron phosphate deployments.