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EnigoMontoya t1_je0mila wrote

Reply to comment by larsschellhas in Is Space-Based Solar Power An Option to Solve Humanity's Energy Hunger After All? by larsschellhas

Bunch of questions here, but starting with a couple...

What's your assumption on the cost of the distributed ground based plants accepting SBSP on a $/MW basis?

What's the breakdown of percent loss from SBSP for the transmission down to ground and conversion into usable AC?

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larsschellhas OP t1_je0yd9s wrote

It's around 50% at the moment, but has no physical limit really. The advantage of microwaves (like Radar) is that they are much less impacted by clouds and weather than visible light.

The receiver stations are also simple antennas which can be manufactured much cheaper than solar PV, therefore making up only a small share of the total CAPEX. I don't have the number off the top of my head, but they can be found in the Roland Berger and Frazer Nash studies.

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EnigoMontoya t1_je11jm3 wrote

Right so the conversion is 50% but the transmission over distance is a distinct loss correct? Yes, microwaves can penetrate the atmosphere, but there is still a cost.

https://ars.els-cdn.com/content/image/1-s2.0-S2352484720317273-gr9.jpg

This diagram from a 2021 study touting a 45% conversion efficiency but notes a huge drop from the transmission... 400 KW -> 10 KW over just 10 KM.

When you consider geosynchronous orbit is all the way out at 35,000 KM. This seems like a major issue. What am I missing?

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larsschellhas OP t1_je11s3v wrote

That there are only around 10-50 km of atmosphere is the way and that accuracy is the primary driver of losses. :)

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larsschellhas OP t1_je1rz1o wrote

Or rather, according to EMROD, the main loss driver is the conversion to microwaves. Reconversion and transmission appear to be relatively efficient.

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