# Natural reservoirs

Nature's own stores: snowpack, lakes, glaciers, ocean and ground heat, and the air's pressure differences.

Source page: https://www.materialinsights.org/energy/e_natural_stores/

Storage · Electrical and system · No. 95

- Storage
- Duration: Seasons and longer
 Storage · Electrical and system · Foundation · Energy

Norway keeps over 87 TWh of energy as water in about 1,100 mountain reservoirs, about half of Europe's reservoir storage.

Chart: Illustration: Natural reservoirs

##### Where it comes from

Chart: Map of where it comes from

Nature charges these stores for free: evaporation lifts water onto mountains, and oceans and rock hold heat, but humans can only manage the release.

##### Three things to know

1. A cubic metre of water falling 100 m holds only about 0.28 kWh, so storing 1 GWh needs about 3.6 million m3.
2. Reservoirs emit about 0.8 Gt CO2e a year, mostly methane from rotting plants under water.
3. Only 37% of the world's long rivers still flow freely.

##### The journey

1. 1 **Sun**Evaporates water and heats air and oceans
2. 2 **Rain and snow**Lift water onto high ground
3. 3 **Natural store**Lakes, snowpack, glaciers, ground heat
4. 4 **Managed release**Dams time when water flows
5. 5 **Turbines**Up to 92% of water energy captured

##### Go deeper pick a tab to open it in full

## Other sections

- [Overview](https://www.materialinsights.org/energy/e_natural_stores/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_natural_stores/correlation/index.md)
- [Science and technology](https://www.materialinsights.org/energy/e_natural_stores/sg-sci/index.md)
- [Engineering and performance](https://www.materialinsights.org/energy/e_natural_stores/sg-eng/index.md)
- [Economics](https://www.materialinsights.org/energy/e_natural_stores/sg-econ/index.md)
- [Impact and additionality](https://www.materialinsights.org/energy/e_natural_stores/sg-impact/index.md)
- [What to track](https://www.materialinsights.org/energy/e_natural_stores/tracking/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_natural_stores/links/index.md)