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Spotlights against global warming

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It is currently fashionable for farmers to plead "global warming" as an excuse to convert tens of acres of farmland into giant arrays of solar panels.

It is true that these apparati generate electricity without directly burning fossil fuel. In some cases, they may even generate enough to offset the carbon footprint of installing them, and even to exceed the carbon that would have been fixed by the perfectly adequate plants that used to be there.

However, all the electricity they generate ends up as heat sooner or later. Indeed, if solar panels do their job by absorbing almost all the incoming sunlight, they are just lowering the overall albedo of the planet. This could be avoided if the solar panels were white, but then they woudn't work.

The solution, really, is obvious. All the output from solar farms needs to be fed directly to vast arrays of LEDs mounted on parabolic reflectors that send their light out into space. The wavelength can be chosen to be least absorbed by the atmosphere on the way out. In this way, we actually increase the effective albedo of the planet.

This is the ideal use for solar-generated electricity, because it can cope with the hourly, daily and seasonal variation in output from the solar panels without causing any inconvenience.

MaxwellBuchanan, Feb 14 2019


       This could get too popular, and people would end up useing the subsidies to power these spotlights with nucular or coal-fired power stations
pocmloc, Feb 14 2019

       I'm sure there'd be some way to finesse that particular problem.   

       A quick calculation tells me that if we can produce a steady 1 million Gigawatts of light and send it spacewards, we offset 1% of all the solar energy reaching Earth, which ought to cool things down quite a lot. The biggest solar farms at the moment produce about 0.5GW, so a few million of these dotted around the globe would solve the whole problem.
MaxwellBuchanan, Feb 14 2019

       Just to tart it up a bit: There are frequency doubling crystals. Finding one that turns IR into visible, then beaming that into space could be done without the electricity part.   

       Using parabolic mirrors and a smaller crystal would likely be possible, cheaper, and more effective than crystal coated mirrors.   

       There is something called the urban heat island effect, where cities warm up more from (I think) absorption of light. Putting these mirror crystals on city rooftops could beneficially lower city temperatures. Now for somebody to actually do the numbers...   

beanangel, Feb 14 2019

       Nice idea, but which village idiot gets to keep their hand on the albedo dial? Ever notice the hysteresis loop from the thermostat dial competition?
tumblewit, Feb 14 2019

       Well, I think a global vote on "a nice comfortable temperature" ought to produce a consensus, or at least a working average. My guess is that it would come out somewhere about 23-26°C, and we should just site these spotlights to bring everywhere to that temperature. It'd be a bit tough on the polar bears but, you know, fuck 'em.
MaxwellBuchanan, Feb 14 2019

       I think instead of rating solar panels by kilowatts they should be measured by their ability to generate warm fuzzy feelings and government funding.   

       Wonder if a nuclear power promotion program with the slogan "Nuke _____ (insert city name here)!" would get people's attention. The small print would go on to say how many trillions of kilowatt hours have been safely provided for tens of millions of people over the years.   

doctorremulac3, Feb 14 2019

       Instead of a nice comfortable temperature everywhere, what about a gradient so you can pick your favorite city based on the temperature... never mind, I think we have come full circle.
tumblewit, Feb 14 2019

       // frequency doubling crystals. Finding one that turns IR into visible //   

       Frequency doubling crystals only work with extremely low-entropy light. With thermal or blackbody radiation, it simply doesn't work.
mitxela, Feb 14 2019

       // frequency doubling crystals// A massive stretch of the meaning of crystal but those green wavy fractal things, that are being replaced by concrete and tarmac, more than double. They work in bright light but need periodic darkness.
wjt, Feb 16 2019

       Gr. "this apparatus": "apparatus" is generally a non-count noun (like "water"), not used in the plural. And, if you do force it into the plural for your own twisted purposes, I'm pretty sure it's fourth declension, so it doesn't have a plural in -i. Compare "status".
pertinax, Feb 16 2019

       How much of this simply heats up the atmosphere? Keeping the beam narrow, like a powerful laser perhaps, seems like the ticket.   

       While you're beaming that much energy into space, might as well make some use out of it with it as the propulsion of a space elevator.
RayfordSteele, Feb 16 2019

       So, it sounds like the goal of global humanity is to use as much solar energy as possible, in the most complex path, leaking as little heat as possible.   

       A lot of rocket fuel production, might be possible. Possibly pushing against the grain with nuclear physics.
wjt, Feb 16 2019


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