Europe's Largest Battery: The 4 GWh German Giga-Project
Germany will host Europe\u2019s largest battery: a 1 GW/4 GWh BESS in J\u00e4nschwalde. Here\u2019s what it means for grid stability, markets, and the Energiewende.
Key takeaways
- Germany will host Europe’s largest battery energy storage system (BESS): a 1 GW / 4 GWh project in Jänschwalde.
- Developed by LEAG with technology from Fluence, the system will help steady the grid, support energy trading, and speed up the Energiewende.
- 4 GWh equals about four hours of power at 1 GW. That is a step change for clean energy reliability in Europe.
- Target completion is 2027–2028, according to Energy-Storage.news.
- Location matters: Jänschwalde sits in a former coal region (Lusatia), showing how clean tech can create a new energy hub.
Get the quick facts (PDF): Download the project fact sheet.
What changed?
On November 7, 2025, LEAG Clean Power GmbH and Fluence announced Europe’s largest battery storage project: a 1 GW / 4 GWh system in Jänschwalde, Germany. Reports from GlobeNewswire, POWER Magazine, Yahoo Finance, and Electrek confirm the scope, partners, and goals.
How big is 4 GWh?
Think simple: 4 GWh means the battery can push out 1 GW for four hours. It’s like a big bank for energy. During windy or sunny hours, it stores extra power. Later, it sends that power back when people need it most.
For scale, one outlet-friendly comparison from InsideEVs says a system like this can power about 100 million LED lights. That shows how large this project really is.
Key project facts
| Feature | Details |
|---|---|
| Capacity | 1 GW power / 4 GWh energy (four-hour duration) |
| Location | Jänschwalde, Germany (Lusatia) |
| Developer / Owner | LEAG Clean Power GmbH |
| Technology provider | Fluence Energy GmbH; solution: Smartstack |
| Primary roles | Grid services, energy trading, system stability, energy security (POWER Magazine) |
| Timeline | Target completion 2027–2028 (Energy-Storage.news) |
Why this matters for Germany
Germany is moving fast on the Energiewende: a shift from coal and gas to clean power. Solar and wind are growing. But they are not steady all day. This battery fills the gaps.
It helps keep the lights on, adds backup for price spikes, and cuts the need for fossil peaker plants. It also helps turn a former coal area into a clean energy center, which supports local jobs and skills.
BESS technology, in simple terms
- Store excess energy: When wind and solar make more power than needed, the battery charges.
- Support the grid: It responds in seconds to keep frequency steady. These are called grid services.
- Shift energy in time: The battery sells power later, when demand and prices are higher. This is energy trading.
- Scale fast: Unlike big dams, batteries can be built and expanded in months to a few years. For context, Germany’s Goldisthal pumped hydro is 1 GW / 8 GWh, but it took decades to plan and build (Energy-Storage.news).
How this compares in Europe
| Project | Size | Location | Status / Notes |
|---|---|---|---|
| GigaBattery Jänschwalde 1000 | 1 GW / 4 GWh | Germany | Europe’s largest announced BESS (GlobeNewswire) |
| ENGIE / Sungrow UK BESS | 200 MW / 800 MWh | United Kingdom | Prior top system benchmark (InsideEvs) |
| ENGIE Vilvoorde BESS | 200 MW / 800 MWh (phased) | Belgium | First 400 MWh commissioned (Strategic Energy) |
| Goldisthal (PHES) | 1 GW / 8 GWh | Germany | Pumped hydro (not a battery), long build time (Energy-Storage.news) |
Why this project is a game-changer for Europe’s grid
- Scale: A 1 GW / 4 GWh BESS can cover short peaks without firing up fossil plants.
- Speed: Batteries react in seconds, keeping the grid stable and lowering costs.
- Market impact: More storage can smooth prices, support more wind and solar, and cut curtailment.
- Strategic value: In a time of energy shocks, storage boosts security and resilience.
Business and policy takeaways
- Policy signal: German leaders have highlighted storage to build a more affordable, secure power system (POWER Magazine).
- ROI insight: Multi-hour BESS taps several revenues at once: fast grid services, capacity, and energy arbitrage. Those stacked values can shorten payback as markets mature.
- Implementation tip: Stage the build in blocks. Connect early segments to start earning services while the rest is built. Pick proven hardware and software (e.g., Fluence Smartstack) to reduce risk.
Printable fact sheet
- Name: GigaBattery Jänschwalde 1000
- Size: 1 GW / 4 GWh (four-hour duration)
- Location: Jänschwalde, Lusatia, Germany
- Developer: LEAG Clean Power GmbH
- Technology: Fluence, Smartstack platform
- Target completion: 2027–2028
- Core uses: Grid stability, energy trading, security support
- Context links: Announcement, Coverage, Timeline
FAQ
What is the largest BESS in Europe in 2025?
The 1 GW / 4 GWh GigaBattery in Jänschwalde is the largest announced battery storage project in Europe (Electrek, POWER Magazine).
Who is building it?
LEAG Clean Power with Fluence Energy providing technology and software (GlobeNewswire).
When will it be ready?
The project targets 2027–2028 for completion (Energy-Storage.news).
How does it help the grid?
It stores extra solar and wind, supports frequency, and shifts power to high-demand hours. That reduces curtailment and lowers the need for fossil backup.
How is it different from pumped hydro?
Both store energy, but batteries build faster and respond in seconds. Pumped hydro is larger for very long storage but takes longer to develop.
Marcus helps organizations implement sustainable practices and evaluates emerging green technologies. Former renewable energy engineer with 15+ years in clean tech industry.
