# Solar heat collectors

Collectors that turn sunlight into useful heat for water, buildings, drying, cooking and industry.

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

Capture · Solar · No. 23

- Capture
- Output: Heat
 Capture · Solar · Foundation · Energy

A simple glazed rooftop collector captures about two-thirds of the sunlight striking it as hot water.

Chart: Illustration: Solar heat collectors

##### Where it comes from

Chart: Map of where it comes from

A coated absorber under glass soaks up sunlight and hands the heat to water or antifreeze, which carries it to a storage tank.

##### Three things to know

1. Solar district heating serves 346 towns and cities; Bracht in Germany gets 75-80% of its heat from the Sun.
2. Only about 1,315 industrial solar heat systems existed in 2024, though half of factory heat is needed below 400 C.
3. Evacuated tubes made up about 69% of world collector capacity in 2021.

##### The journey

1. 1 **Sunlight**Falls on a roof or collector field
2. 2 **Absorber**Coated metal under glass or vacuum
3. 3 **Fluid**Water or antifreeze carries the heat
4. 4 **Storage tank**From household tanks to giant pits
5. 5 **Uses**Hot water, heating, drying and factory steam
 Covered in [The laws of energy: conservation, entropy and efficiencyEnergy](https://www.materialinsights.org/learn/energy/laws-of-energy/)[Making electricity: thermal, nuclear, hydro, wind and solarEnergy](https://www.materialinsights.org/learn/energy/making-electricity/)[Power density: why land and space matterEnergy](https://www.materialinsights.org/learn/energy/power-density/)

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

## Other sections

- [Overview](https://www.materialinsights.org/energy/e_solar_heat/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_solar_heat/correlation/index.md)
- [Efficiency](https://www.materialinsights.org/energy/e_solar_heat/efficiency/index.md)
- [Techniques](https://www.materialinsights.org/energy/e_solar_heat/techniques/index.md)
- [Resources and labour](https://www.materialinsights.org/energy/e_solar_heat/resources/index.md)
- [Impact on the biosphere](https://www.materialinsights.org/energy/e_solar_heat/biosphere/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_solar_heat/links/index.md)