# Natural reservoirs: Overview

Nature's own batteries: snow, lakes, oceans and hot rock

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

Nature's own batteries: snow, lakes, oceans and hot rock What this tile covers Nature's own stores: snowpack, lakes, glaciers, ocean and ground heat, and the air's pressure differences. Share of use 6.7% share of world stored energy (2021)

Share of the world's stored energy (energy capacity held, TWh, latest year 2019 to 2026) across the forms with figures, about 22,551 TWh; fuel stocks dominate. Battery and other stores count capacity, not state of charge (calculated) Hydropower reservoirs worldwide can hold about 1,500 TWh of electricity over a full cycle (IEA, 2021), of 22,551 TWh. Snowpack, ocean and ground heat are left out because they are not drawn on as stores. Source: [Dams, 'water batteries' in the mountains (reporting the IEA Hydropower Special Market Report 2021)](https://www.renewablematter.eu/en/dams-water-batteries-in-the-mountains), Renewable Matter.

#### Key facts

| **Duration** | Seasons and longer |
|---|---|

#### Included from the reference tables

- Reservoirs, lakes, snowpack, glaciers
- Ocean and geothermal heat
- Atmospheric pressure and temperature gradients

#### Also in Electrical and system
[SC Capacitors and supercapacitors](https://www.materialinsights.org/energy/e_supercaps/)[SMES Superconducting magnetic storage](https://www.materialinsights.org/energy/e_smes/)[V2G Demand response and vehicle-to-grid](https://www.materialinsights.org/energy/e_demand_flex/)

Explore paths from here
 More on this tile in the tabs above: science and technology, engineering and performance, economics, impact and additionality, what to track.

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_natural_stores/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)