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Old 09-01-2019, 03:01 PM   #6715 (permalink)
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Originally Posted by sendler View Post
CalTech is working on an orbital space based solar electricity scheme using microwaves to transmit the power back to Earth with banks of millions of these 10 cm tiles. I am surprised to hear that most of the research in the USA and in China is still headed in this direction. Microwave power from orbit requires a 1:10 ratio of antenna diameter. To keep the energy levels on the ground to levels that are comparable with what we are exposed to from the sun (in case the aiming goes astray and starts shining on a city before we can shut it down), 0.75 GigaWatt requires a 1 km diameter assembly of these tiles in orbit, all aimed with micro radian precision, onto a 10 km receiving antenna on the ground. After learning about the scale of the antenna requirements versus the total power they could transmit, I was immediately convinced that transmitting via lasers would be much better and would make any future ground based standard solar panel installations forward compatible with just perhaps the inclusion of adjustable tilt and single axis tracking which are beneficial for maximizing sunlight anyway.

Reminds me of the short story "Reason" by Isaac Asimov. I read that while locked up.

...not sure how orbital solar collection is supposed to be more cost effective than ground based. It solves the predictability problem since there's no weather to contend with, but sending stuff into orbit has got to get a lot cheaper.

I wonder, do you have the solar collectors orbit on the vertical axis to earth, over the poles, so that they never encounter the shadow of earth?

What orbital height is ideal?
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