Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Japan will try to beam solar power from space by 2025

engadget.com

Post reply on HN
Print view View original

91–98 of 98 posts

Re: Japan will try to beam solar power from space by 2025

#91

Post by jvanderbot »

JoeAltmaier wrote: post #90
jvanderbot wrote: post #56

Earlier quoted context omitted.

Every reduction in solar cost makes it more efficient to buy panels on earth. The installation cost for space is so much more than the installation cost for earth. Even at 10x the cost, which is orders of magnitude off, what do we have? We have a system in space at 10 the cost that needs a solar array sized receiving plant (double the cost) and has transmission losses (increase size of space and ground installations…

Those are the numbers that are changing. Transmission losses have become fairly tiny. The 'ludicrous proposition' is similar to the turn-of-the-century folk who yelled 'get a horse!'

Well, I'm open to new numbers. I'll have to re-read TFA and dive deeper at some point. But last time I checked, and last time I asked smarter people than me what they thought, it was quite a ways off.

Re: Japan will try to beam solar power from space by 2025

#92

Post by tommiegannert »

rich_sasha wrote: post #87
tommiegannert wrote: post #84

Is it a good idea to put more solar irradiation onto Earth than we already have? I thought climate change was due to us causing accumulation of solar that would otherwise diffuse into space. Assuming they're not shading Earth, robbing someone else of sun. Are they? Is Mr Burns' solar blackout machine becoming a thing?

I guess depends what wavelengths are used. If it is something not absorbed by the atmosphere then the argument is moot. I think some microwave lengths for the bill.

Why does it have to be absorbed by the atmosphere to be a problem?

If the energy reaches the surface, and is absorbed there, it will eventually become heat as we use it. At that point, we've added heat to a system we're actively trying to cool.

Re: Japan will try to beam solar power from space by 2025

#93

Post by cykros »

35mm wrote: post #15

I’m no rocket scientist but surely it’s cheaper to build more panels and batteries on Earth? Launching stuff into orbit is expensive in cash and emissions.

The other thing that would be cheaper would be building molten salt cooled nuclear reactors, instead of continuing to use the water cooled once that are so prone to hydrogen explosions. I'm not a nuclear engineer, but I suspect you may even be able to re-use a lot of existing infrastructure in the process.

Could even be safer if their system for beaming electricity has the potential to be compressed to a point where it turns it into a lightning gun.

Re: Japan will try to beam solar power from space by 2025

#94

Post by cykros »

JoeAltmaier wrote: post #90
jvanderbot wrote: post #56

Earlier quoted context omitted.

Every reduction in solar cost makes it more efficient to buy panels on earth. The installation cost for space is so much more than the installation cost for earth. Even at 10x the cost, which is orders of magnitude off, what do we have? We have a system in space at 10 the cost that needs a solar array sized receiving plant (double the cost) and has transmission losses (increase size of space and ground installations…

Those are the numbers that are changing. Transmission losses have become fairly tiny. The 'ludicrous proposition' is similar to the turn-of-the-century folk who yelled 'get a horse!'

[flagged]

Re: Japan will try to beam solar power from space by 2025

#95

Post by blueflow »

JoeAltmaier wrote: post #89
blueflow wrote: post #54

Earlier quoted context omitted.

> The costs are all going in the direction to make space-based solar the winning option Citation needed. I'd especially like to see the calculation against the launch costs and the expected lifetimes of solar cells.

Really? We need to cite the worldwide phenomenon of drastically reducing lift costs? Astronomical growth in cheap thin solar panels? Rising real estate prices? No. No I'm not going to dignify this with a 'citation'.

Then do the calculation with energy instead of money. At some point you are better off putting the rocket fuel into a ground power station.

Re: Japan will try to beam solar power from space by 2025

#96

Post by rich_sasha »

tommiegannert wrote: post #92
rich_sasha wrote: post #87

Earlier quoted context omitted.

I guess depends what wavelengths are used. If it is something not absorbed by the atmosphere then the argument is moot. I think some microwave lengths for the bill.

Why does it have to be absorbed by the atmosphere to be a problem? If the energy reaches the surface, and is absorbed there, it will eventually become heat as we use it. At that point, we've added heat to a system we're actively trying to cool.

The idea is that the beam hits some receiver and most of it turns into electricity, not heat.

Of course the elect city eventually turns into heat too...

Re: Japan will try to beam solar power from space by 2025

#97

Post by ricardobeat »

dragontamer wrote: post #73
ricardobeat wrote: post #72

Earlier quoted context omitted.

Do you have an example of a place where that is a significant issue? The upstream flow is the same as it was before a dam is built. You’d imagine this would only become a problem if nearly the entire flow was being consumed, which is unthinkable.

> You’d imagine this would only become a problem if nearly the entire flow was being consumed, which is unthinkable. The Colorado River hasn't touched the ocean in decades man. Its been fully consumed for a long, long time. https://en.wikipedia.org/wiki/Colorado_River_Delta#After_dam... Hoover Dam will probably not be a pumped-hydro plant in our lifetime. Its not about technology, its about politics and water rights…

Whoa. I had no idea that line was crossed long ago.
Post reply on HN