Nuclear fusion reaction releases almost twice the energy put in

throwaway389430@lemmy.cafe to News@lemmy.world – 629 points –
Nuclear fusion reaction releases almost twice the energy put in
newscientist.com
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There is a very efficient way to beam solar power from space. It is called light.

It's not efficient, a huge amount of it gets diffused or absorbed

It doesn't need to be efficient. Capture all the light that hits earth for 5 minutes and that's the world energy demand for a year.

It’s not efficient, a huge amount of it gets diffused or absorbed

The amount that's left over though is more than enough, especially with today panels which only convert a very small percentage of that remaining energy.

As the panels improve even more they'll be a very large energy surplus, even with how much solar light actually gets through the atmosphere.

Wow, you're right! We should just build a Dyson sphere around the sun. 100% efficiency achieved. What could possibly go wrong?

Did you understand the person you respond to as saying its inefficient because the sun shines in other directions than the array proposed?
I'm pretty sure the person talked specifically about the beam from the array to earth being inefficient.

I was joking, but apparently nobody picked up on my snarky sarcasm. Disregard.

The nice thing about space is that there isn't any weather up there to make the solar panels dirty etc. There's also a lot of space, which solar panels need a lot of.

How would you move the power down to earth?

Microwave transmission is what's usually said, then someone says anything in the beam's path will get zapped, then it's pointed out the energy density isn't that high. Just wanted to shortcut that for ya

But what if I want to zap anything in the beam's path?

Then a meddlesome British agent will interfere.

Well at least I still have my cat.

And my moon laser

How would you move the power down to earth?

Last time I read up on it it was via converting the energy into microwaves and beaming it down.

I think masers (microwave lasers) are the new theory for achieving this, previously it was beaming microwave down much like your microwave oven beams your food.

It’s not that new. Sim City 2000 included a power plant that was just a receiving dish for a maser

Funny thing is, no matter how you arrange to do that it becomes a de-facto death ray. Stick a terawatt of solar panels in space, use the power to shine a laser/maser down to earth, then build a station to turn the laser power back to electricity? Great, until some hacker figures out how to control where the laser is pointed. Then you get Dr. Evil holding the world for ransom.

Nah it's not really bad at all:

The use of microwave transmission of power has been the most controversial issue in considering any SPS design. At the Earth's surface, a suggested microwave beam would have a maximum intensity at its center, of 23 mW/cm2 (less than 1/4 the solar irradiation constant), and an intensity of less than 1 mW/cm2 outside the rectenna fenceline (the receiver's perimeter). These compare with current United States Occupational Safety and Health Act (OSHA) workplace exposure limits for microwaves, which are 10 mW/cm2,[original research?] - the limit itself being expressed in voluntary terms and ruled unenforceable for Federal OSHA enforcement purposes.[citation needed] A beam of this intensity is therefore at its center, of a similar magnitude to current safe workplace levels, even for long term or indefinite exposure.

https://en.wikipedia.org/wiki/Space-based_solar_power?wprov=sfla1

The nice thing about space is that there isn’t any weather up there to make the solar panels dirty etc.

There's a lot of junk though can that can damage those panels.

Space Lane cleaner was going to become a thing at some point anyway...

And we can position a bunch over the poles to help stave off climate change.

The poles aren’t really the place that need that the most.

You wouldn't think so but them staying super cold helps stabilize a large chunk of our climate. Also throwing shade on arable land isn't great for food production.

We dont need to collect it in space, just direct more of it to certain ground based collectors?