Energy storage is key to optimal use of renewable energy in Local Energy Communities (LEGs). It enables storing excess energy and retrieving it when needed – making LEGs more independent and efficient.
In this comprehensive guide, you'll learn everything about various storage technologies for LEGs, their advantages and disadvantages, as well as economics and integration.
Why Energy Storage for LEGs?
Main Benefits
1. Optimization of Self-Consumption Rate:
- Store excess solar energy
- Use at night/winter
- Typical increase: 60-80% self-consumption → 80-95%
2. Stabilization of Supply:
- Balance production fluctuations
- Secure supply
- Reduced grid dependence
3. Economics:
- Higher self-consumption rate = more savings
- Reduced grid purchases
- Additional revenue possible
Storage Technology 1: Battery Storage
Lithium-Ion Batteries
How It Works:
- Electrochemical storage
- Fast charge/discharge cycles
- High efficiency (85-95%)
Properties:
- Capacity: 5-100 kWh (typical)
- Lifespan: 5,000-10,000 cycles
- Costs: 800-1,200 CHF/kWh
- Efficiency: 85-95%
Advantages:
- ✅ Fast response
- ✅ High efficiency
- ✅ Compact
- ✅ Low maintenance
Disadvantages:
- ⚠️ Limited lifespan
- ⚠️ Higher costs
- ⚠️ Environmental aspects
Redox-Flow Batteries
Properties:
- Capacity: 20-500 kWh
- Lifespan: 10,000+ cycles
- Costs: 1,000-1,500 CHF/kWh
- Efficiency: 70-85%
Lead-Acid Batteries
Properties:
- Capacity: 10-200 kWh
- Lifespan: 1,500-3,000 cycles
- Costs: 400-600 CHF/kWh
- Efficiency: 70-85%
Storage Technology 2: Hydrogen
Hydrogen Storage
How It Works:
- Electrolysis (water → H2)
- Storage under pressure
- Power generation (fuel cell)
Properties:
- Capacity: 100-10,000 kWh
- Lifespan: 20+ years
- Costs: 2,000-5,000 CHF/kWh
- Efficiency: 40-60% (round trip)
Advantages:
- ✅ Very large capacity
- ✅ Long-term storage (months)
- ✅ No self-discharge
Disadvantages:
- ⚠️ Low efficiency
- ⚠️ High costs
- ⚠️ Complex technology
Storage Technology 3: Pumped Storage
Pumped Storage Power Plants
Properties:
- Capacity: 1,000-100,000 kWh
- Lifespan: 50+ years
- Costs: 500-1,000 CHF/kWh
- Efficiency: 70-85%
Advantages:
- ✅ Very large capacity
- ✅ Very long lifespan
- ✅ High power
Disadvantages:
- ⚠️ Geographic requirements
- ⚠️ High investments
Economics of Energy Storage
Cost Comparison
| Technology | Cost/kWh | Lifespan | Efficiency | Suitable for |
|---|---|---|---|---|
| Lithium-Ion | 800-1,200 CHF | 5,000-10,000 cycles | 85-95% | Daily balancing |
| Redox-Flow | 1,000-1,500 CHF | 10,000+ cycles | 70-85% | Medium storage |
| Hydrogen | 2,000-5,000 CHF | 20+ years | 40-60% | Seasonal storage |
| Pumped Storage | 500-1,000 CHF | 50+ years | 70-85% | Large capacities |
Integration into LEGs
Technical Integration
1. Connection:
- Connection with solar panels
- Smart Grid Integration
- Control system
2. Control:
- Intelligent charge/discharge strategies
- Optimization based on forecasts
- Load management
Frequently Asked Questions (FAQ)
Which storage technology is best?
Depends on:
- Need (short-/long-term)
- Budget
- Available space
- Geographic conditions
Usually: Lithium-ion for daily balancing.
Is storage financially worth it?
Often yes, if:
- High own production
- Good grants
- Rising electricity prices
- Optimized use
How large should storage be?
Typically:
- 1-2 kWh per kWp solar capacity
- For daily balancing
- Larger for longer storage
Next Steps
Interested in energy storage?
- Analyze needs: Review your production
- Choose technology: Evaluate options
- Check grants: Use available grants
- Contact Upgrid: Get advice
Energy storage makes LEGs even more efficient!
Related Articles:
- Solar Panels in LEG: Planning, Installation, Integration
- Smart Grid Technology for Energy Communities
- LEG Digitization: Platforms, Apps and Management Systems
- Winter Preparation: Ensuring Energy Supply
About Upgrid: Upgrid supports you in integrating energy storage into LEGs. Visit Upgrid.ch for more information.