Hydropower has long been a cornerstone of renewable energy. However, as energy systems shift toward increased reliance on wind and solar power, the need for flexible, reliable energy sources has never been greater. A new paper from China Institute of Water Resources and Hydropower Research [39.9°N, 116.3°E] into optimising existing hydropower reservoirs presents a transformative strategy: expanding capacity to enhance energy system flexibility without building new infrastructure. This approach offers practical solutions where hydropower already plays a key role in sustainable energy transitions.
Making the Most of Existing Resources
Traditional hydropower systems focus primarily on generating energy, often overlooking their potential to support modern, flexible grids. The research introduces a Capacity Expansion Optimisation Model (CEOM), which explores how to enhance flexibility in hydropower plants by adding turbines to existing reservoirs without constructing new dams.
Key findings include:
- Enhanced Flexibility: Expanding capacity allows plants to quickly adjust energy output, balancing fluctuations from intermittent renewables like wind and solar.
- Improved Efficiency: Each unit of capacity expansion in annually regulated reservoirs provides 0.80 units of upward flexibility, significantly higher than the 0.59 units in daily-regulated systems.
- No Additional Infrastructure Needed: Expansions utilise existing reservoirs, minimising environmental impact and avoiding high construction costs.
How It Works
The CEOM optimises the placement and operation of new turbines by considering factors such as:
- Reservoir Storage: Larger reservoirs with higher initial storage can store more water for energy generation, maximising flexibility.
- Inflow Variability: Annually regulated reservoirs see substantial flexibility improvements with increased water inflow, while daily-regulated reservoirs are more constrained by size.
- Hydraulic Connections: Jointly managing cascaded hydropower systems (upstream and downstream plants) amplifies overall flexibility.
Key Takeaways
- Supporting Renewable Energy Integration
- Hydropower’s ability to balance grid variability is critical for regions with significant wind or solar capacity. For instance, expanding capacity in Canadian or Scandinavian reservoirs could stabilise grids during winter months when energy demand peaks.
- Low-Carbon Energy Security
- By enhancing hydropower’s flexibility, countries reduce reliance on fossil fuel-based backup systems, cutting emissions while ensuring reliable energy supply.
- Economic and Environmental Wins
- Using existing infrastructure avoids the ecological and financial costs of new dams. For Denmark and similar nations, this aligns with sustainability goals while providing a cost-effective energy solution.
Implications for Everyday Life
For individuals and communities, optimising hydropower translates to more stable, affordable, and green electricity. Flexible hydropower systems can store energy during windy or sunny periods and release it when demand is highest—keeping lights on and costs down even in extreme weather.
Looking Ahead
The research underscores the untapped potential of hydropower. By rethinking how existing resources are used, we can accelerate the energy transition and meet climate goals without sacrificing reliability or sustainability.
So, more hydropower is not just about generating green energy; but creating smarter, sufficient, adaptable energy systems for a sustainable, clean future.
Source
Capacity optimization of existing reservoir hydropower expansion and its impact on power system flexibility, Applied Energy, 2025-01-01
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