01 How It Works
Water stored behind a dam contains potential energy. When released through penstocks, gravity accelerates it into turbines, converting kinetic energy into rotational energy, then electricity via generators. Run-of-river plants use natural water flow without large reservoirs. Pumped-storage hydro - the world's largest form of grid energy storage - pumps water uphill when power is cheap and releases it when demand peaks.
02 Pros & Cons
โ Advantages
- Reliable and dispatchable
- Long lifespan (50โ100 yr)
- Pumped storage for grid balance
- Low operating costs
โ ๏ธ Disadvantages
- Ecosystem disruption
- Displaces communities
- Drought vulnerability
- Limited new large sites
03 Future Outlook
While large dam construction has slowed due to environmental concerns, small and micro-hydro is growing in developing regions. Marine hydrokinetic energy (tidal, river current) represents a significant untapped resource. Upgrading existing dams with modern turbines can unlock substantial efficiency gains.
04 Fun Fact
The Three Gorges Dam in China is the world's largest power station of any kind, producing 22,500 MW.