# Space-based solar power

Collectors in orbit that would beam energy down to Earth; experimental.

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

Capture · Emerging · No. 49

- Capture
- Output: Electricity (experimental)
 Capture · Emerging · Foundation · Energy

A satellite 35,786 km up could catch sunlight 99.7% of the time and beam it to Earth as microwaves.

Chart: Illustration: Space-based solar power

##### Where it comes from

Chart: Map of where it comes from

In geostationary orbit the Sun almost never sets. Mirrors concentrate sunlight onto panels, and a phased array beams the power down at 2.45 GHz to a ground antenna.

##### Three things to know

1. Caltech's MAPLE satellite, launched in January 2023, beamed power to receivers about a foot away in orbit.
2. A 2 GW reflector design would need about 11.5 km² of solar panels in orbit and a ground antenna 6 km across.
3. Rocket soot holds heat almost 500 times better than soot from other sources, so thousands of launches raise atmospheric worries.

##### The journey

1. 1 **Sunlight in orbit**Almost no night or cloud
2. 2 **Solar panels**Mirrors focus light; cells make DC
3. 3 **Transmitter**Phased array forms a microwave beam
4. 4 **Beam**Crosses 36,000 km and the atmosphere
5. 5 **Rectenna**Kilometre-wide antenna turns microwaves into DC
6. 6 **Grid**Power fed to users

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

## Other sections

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