Hydropower is a small but stable contributor to the UK’s renewable energy mix. Compared with wind and solar, hydro plays a much smaller role because the UK’s geography offers limited sites suitable for large dams. However, it remains valuable for reliable, dispatchable electricity and energy storage.
Types of Hydropower in the UK
1. Conventional Hydropower (Run-of-river & reservoir)
- Mostly located in Scotland, Wales, and northern England.
- Many plants were built mid-20th century and continue operating with upgrades.
- Provides steady baseload renewable power.
2. Pumped Storage Hydropower (PSH)
This is the UK’s most important hydropower asset, used for grid balancing and energy storage.
Major sites include:
- Dinorwig (Electric Mountain), Wales – one of the largest PSH plants in Europe.
- Ffestiniog, Wales
- Cruachan, Scotland (also called the “Hollow Mountain”)
These facilities:
- Store excess electricity by pumping water uphill
- Release it during demand peaks
- Provide fast response, helping stabilize the grid
3. Micro and Small Hydropower
- Hundreds of small schemes across rivers and old mill sites.
- Often community-owned or privately operated.
- Useful in rural areas but small overall capacity.
Role in the UK Energy Mix
- Hydropower contributes only a few percent of the UK’s renewable electricity.
- Pumped storage doesn’t generate new energy, but it is critical for grid stability, especially with increasing wind/solar.
Future Development
Growth potential is limited because:
- Most viable sites are already developed.
- Environmental protections restrict new large dams.
However:
- Upgrading existing facilities can improve capacity.
- More pumped storage is being proposed to support renewable expansion.
- Innovative small-scale hydro technologies may add local generation.