5 ms·

Dumb question but what about mirrors? Couldn’t we redirect sunlight to a fixed point on earth that has solar panels?

biomcgary 4y ago
I like the idea, but there are a few questions I have for the plausibility of this approach. 1. Does mylar (or weight equivalent have enough reflectivity and flatness) to target a ground station? 2. How much light can be concentrated before becoming a risk (e.g., birds above solar panels, human eyes in vicinity)? 3. How fast will the mirror material degrade from solar wind and micrometeorites? I assume someone has considered this scenario previously, but I imagine that SpaceX lift capacity and price might change the economics.
Cthulhu_ 4y ago
Solar panels drop efficiency the warmer they get; focusing more sunlight on a space will heat that up. There's solar heat based power stations, using mirrors that focus light on a point or a pipe to heat up oil; the question there is, would they become more effective if they get more light? 1 square meter of ground currently receives 1370 watts of energy (if my quick google is accurate); if this can be captured, you can do a back of the napkin calculation of how much you need. It's already been posited that filling a relatively small patch of e.g. a desert can fulfil all of europe's energy needs - no space things needed.
TrainedMonkey 4y ago
Possible but highly inefficient for power generation. Need massive amount of mirrors with pointing + stationkeeping. For medium orbits will need a huge amount of receiver sites + beefy prop & pointing systems. For Geo will need a truly staggering amount of mirrors + sophisticated focusing + massive receiver sites on the planet. Anywhere you point the beam will have massive ecology / weather disruptions... Probably not suitable for human habitation in a huge area due to atmosphere dispersing the beam. See https://en.wikipedia.org/wiki/Space_mirror_(climate_engineering) https://en.wikipedia.org/wiki/Space_mirror_(climate_engineer... for more info. One cool thing we could do is slightly boost the amount of sunlight northern latitude cities receive. This will make solar panels there more viable and will make cities far more livable in the winter season. This could also be done seasonally. This is a cool example https://www.theguardian.com/world/2013/nov/06/rjukan-sun-norway-town-mirrors https://www.theguardian.com/world/2013/nov/06/rjukan-sun-nor...
deleted 4y ago
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I like the idea, but there are a few questions I have for the plausibility of this approach. 1. Does mylar (or weight equivalent have enough reflectivity and flatness) to target a ground station? 2. How much light can be concentrated before becoming a risk (e.g., birds above solar panels, human eyes in vicinity)? 3. How fast will the mirror material degrade from solar wind and micrometeorites? I assume someone has considered this scenario previously, but I imagine that SpaceX lift capacity and price might change the economics.

Cthulhu_ 4y ago

Solar panels drop efficiency the warmer they get; focusing more sunlight on a space will heat that up. There's solar heat based power stations, using mirrors that focus light on a point or a pipe to heat up oil; the question there is, would they become more effective if they get more light? 1 square meter of ground currently receives 1370 watts of energy (if my quick google is accurate); if this can be captured, you can do a back of the napkin calculation of how much you need. It's already been posited that filling a relatively small patch of e.g. a desert can fulfil all of europe's energy needs - no space things needed.

TrainedMonkey 4y ago

Possible but highly inefficient for power generation. Need massive amount of mirrors with pointing + stationkeeping. For medium orbits will need a huge amount of receiver sites + beefy prop & pointing systems. For Geo will need a truly staggering amount of mirrors + sophisticated focusing + massive receiver sites on the planet. Anywhere you point the beam will have massive ecology / weather disruptions... Probably not suitable for human habitation in a huge area due to atmosphere dispersing the beam. See https://en.wikipedia.org/wiki/Space_mirror_(climate_engineering) https://en.wikipedia.org/wiki/Space_mirror_(climate_engineer... for more info. One cool thing we could do is slightly boost the amount of sunlight northern latitude cities receive. This will make solar panels there more viable and will make cities far more livable in the winter season. This could also be done seasonally. This is a cool example https://www.theguardian.com/world/2013/nov/06/rjukan-sun-norway-town-mirrors https://www.theguardian.com/world/2013/nov/06/rjukan-sun-nor...

deleted 4y ago

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