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dullcrisptoday at 4:03 AM3 repliesview on HN

Okay but why not take that slightly larger solar panel and leave it on Earth?

Is the sunlight millions of times brighter beyond the atmosphere? I don’t get it.


Replies

ericdtoday at 4:15 AM

In space, that solar panel is always in the sunlight. No clouds, no night time. Weirdly enough, earth is a more challenging environment in some ways for solar. You need to lay out >3x the number of panels on earth to get the same power production, and you need batteries or a grid interconnection as a buffer.

Also, there's a populist backlash on building datacenters, power transmission infra, and power generation in many areas on earth. Locally, we have a number of people complaining about solar arrays going up on farmland, even though it's the farmers choosing to do it. "It's an eyesore".

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piloto_ciegotoday at 4:09 AM

You have to ask permission to build it somewhere. Nobody is going to stop you in space.

dzhiurgistoday at 4:44 AM

> Okay but why not take that slightly larger solar panel and leave it on Earth?

Because panel cap factor is about 10-20% to begin because day and night exists on earth. Say you wanted to power it on solar + batteries and picked Australia. You pick place that has decent port and most exposure, i.e. Port Hedland. In winter, daily average drops by 20%. Also because atmosphere - 30% less insolation when compared to space. Finally add 10-45% cooling losses.

Which effectively means you need something at least 10-20x more panels + batteries to match space.