Bio-effects
It will be necessary to implement a phase control system that may detect if the uplink pilot beam transmitter at the rectenna is shut off, i.e. the beam will be refocused. This will drop the peak intensity of the beam at the ground level to 0.003 mW/cm2 and the beam width greatly increases.[11] This defocused beam is less than the ambient level of television transmission in an average city (0.01mW/cm2). According to the DOE/NASA 1980 study, preliminary investigations show that no major impairment of avian, animal, or humans or their ecosystems would be sustained outside of the rectenna sites. The site locations should be remote and in sparsely populated areas. Also, a note in the study is made on attempts of terrorists to refocus the beam with malicious intent. To thwart these attempts, in the phasing system of the rectenna, sensors will be employed to detect any large unexpected changes in incident power density. This would cause the transmitting antenna to cease normal operations and/or redirect the beam.[11]
Atmosphere
According to the study referenced above in Bio-Effects, most of the waste heat would be dissipated in space and the amount that is not would be close to the heat produced by suburban developments near large cities. Localized effects would depend on the environmental surroundings and it is unclear what the specific effects would be. Regional weather patterns should not be affected at the rectenna sites and current power generating systems with comparable capacities to our system would have a greater affect than the Space Solar Power system described here.[11] Ozone changes due to excess heat generation globally averaged would have negligible affects.
Aircraft
There will be issues with current communications systems, but these can be mitigated by various techniques. These issues would be most prominent around the area of the collector (within 100km) and in space. Filters and shielding would be required by other satellite systems and ground equipment. Also, high flying aircraft may need additional shielding for their communications electronics.[11]
