# Space-based solar power: Impact on the biosphere

Microwave beams, rocket soot and the space debris problem

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

What this tab covers Effects on human, animal, plant, fungal and microbial life and on whole ecosystems: in the short term (construction and early years), medium term (operating life) and long term (decommissioning and legacy).

Main concerns are microwave beam safety, launch emissions in the upper atmosphere, rectenna land use and space debris. None has been measured at scale, because no system exists.
 Life-cycle emissions, NASA RD1 and RD2 baseline 26.6 and 40.4 g CO2e/kWh^[1](https://www.nasa.gov/wp-content/uploads/2024/01/otps-sbsp-report-final-tagged-approved-1-8-24-tagged-v2.pdf) Share of life-cycle emissions from launch 64% (RD1), 72% (RD2)^[1](https://www.nasa.gov/wp-content/uploads/2024/01/otps-sbsp-report-final-tagged-approved-1-8-24-tagged-v2.pdf) Peak microwave intensity at rectenna centre (ESA study design) 245 W/m2^[2](https://editor.fnc.co.uk/media/fi4pvbgv/space-based-solar-power-final-report.pdf) Rectenna land per system (ESA study) about 50 km2 per 1.44 GW^[2](https://editor.fnc.co.uk/media/fi4pvbgv/space-based-solar-power-final-report.pdf)

#### Effects over time

| Life affected | Short term | Medium term | Long term |
|---|---|---|---|
| **Humans**^[1](https://www.nasa.gov/wp-content/uploads/2024/01/otps-sbsp-report-final-tagged-approved-1-8-24-tagged-v2.pdf)^[2](https://editor.fnc.co.uk/media/fi4pvbgv/space-based-solar-power-final-report.pdf)^[9](https://ntrs.nasa.gov/api/citations/19810011135/downloads/19810011135.pdf) | Launch-site activity for thousands of flights. | Peak beam intensity at the rectenna centre is 245 W/m2 in the ESA study design; a 1980 US assessment kept exposure below 0.1 mW/cm2 (1 W/m2) at the exclusion boundary. | Debris from failed or abandoned satellites; NASA notes the industry both suffers from and adds to debris. |
| **Animals**^[2](https://editor.fnc.co.uk/media/fi4pvbgv/space-based-solar-power-final-report.pdf)^[9](https://ntrs.nasa.gov/api/citations/19810011135/downloads/19810011135.pdf) | Little evidence of effect. | Birds and insects crossing the main beam would be exposed to up to 23 mW/cm2 (230 W/m2) in the 1980 design; the ESA study says effects on fauna need to be better understood. | Little evidence of effect. |
| **Plants**^[9](https://ntrs.nasa.gov/api/citations/19810011135/downloads/19810011135.pdf) | Clearance or shading under rectenna structures. | Plants under the rectenna would receive 0.01 to 1.0 mW/cm2 in the 1980 design. | Little evidence of effect. |
| **Fungi and soil life**^[2](https://editor.fnc.co.uk/media/fi4pvbgv/space-based-solar-power-final-report.pdf) | Little evidence of effect. | Little evidence of effect. | Little evidence of effect. |
| **Ecosystems**^[1](https://www.nasa.gov/wp-content/uploads/2024/01/otps-sbsp-report-final-tagged-approved-1-8-24-tagged-v2.pdf)^[8](https://www.ucl.ac.uk/news/2022/jun/climate-damage-caused-growing-space-tourism-needs-urgent-mitigation) | Rocket soot particles are almost 500 times more efficient at holding heat than soot from all other sources; frequent launches could undermine ozone recovery. | Life-cycle emissions of 27-40 g CO2e/kWh (NASA baseline), 64-72% from launch, excluding upper-atmosphere effects. | Little evidence of effect. |

#### How the effects are reduced

Designers keep beam intensity low and spread over a large rectenna, with exclusion zones where intensity is higher. Rectenna land can be fenced and kept under low vegetation. Reusable launchers and cleaner propellants would cut launch emissions, the largest share of the footprint, and disposal orbits reduce debris. The ESA study stresses that safe beam intensities and effects on flora, fauna and the atmosphere still need agreement and research.

#### Sources

1. [Space-Based Solar Power (Office of Technology, Policy, and Strategy)](https://www.nasa.gov/wp-content/uploads/2024/01/otps-sbsp-report-final-tagged-approved-1-8-24-tagged-v2.pdf) NASA, 2024
2. [Space-Based Solar Power: final report (cost-benefit study for ESA SOLARIS)](https://editor.fnc.co.uk/media/fi4pvbgv/space-based-solar-power-final-report.pdf) Frazer-Nash Consultancy, 2022
3. [Climate damage caused by growing space tourism needs urgent mitigation (Ryan et al., Earth's Future)](https://www.ucl.ac.uk/news/2022/jun/climate-damage-caused-growing-space-tourism-needs-urgent-mitigation) University College London, 2022
4. [Environmental Assessment for the Satellite Power System: Microwave Health and Ecological Effects (DOE/ER/10035-2)](https://ntrs.nasa.gov/api/citations/19810011135/downloads/19810011135.pdf) US Department of Energy / NASA NTRS, 1980

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_space_solar/index.md)
- [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)
- [Relationships](https://www.materialinsights.org/energy/e_space_solar/links/index.md)