Space Solar Power -- How Much More Power Can Be Collected?

[Saghost]

I think we'll see solar power in space with transmission to earth around the same time as we have an operative space elevator. Solar power on earth is just too cheap, relative to the cost of launching things into space for the forseeable future.

I saw a theoretical study someone put together for a space elevator. You need a material that is at least four times the strength of carbon nanotubes for it to be possible at all, and if it ever fails or gets damaged it has the potential to wipe out all life on the planet as it wraps itself around the equator with far more force than an asteroid impact.

I agree the core points if both your post and the one above it - space based solar can deliver massively greater amounts of per unit area (which is what the OP asked,) but we would need a much cheaper way of getting it to orbit for that to make any kind of sense.

At this point, we don't need that kind of power, anyway - current generation solar panels located in and near habitable areas could easily meet our total demand annually - though we'd need a whole lot of storage and/or a lot more transmission capacity to make it practical.
Walter

 

[Yggdrasill]

I saw a theoretical study someone put together for a space elevator. You need a material that is at least four times the strength of carbon nanotubes for it to be possible at all, and if it ever fails or gets damaged it has the potential to wipe out all life on the planet as it wraps itself around the equator with far more force than an asteroid impact.

I agree the core points if both your post and the one above it - space based solar can deliver massively greater amounts of per unit area (which is what the OP asked,) but we would need a much cheaper way of getting it to orbit for that to make any kind of sense.

At this point, we don't need that kind of power, anyway - current generation solar panels located in and near habitable areas could easily meet our total demand annually - though we'd need a whole lot of storage and/or a lot more transmission capacity to make it practical.
Walter

There is certainly some FUD involved when it comes to space elevators. A space elevator is theoretically feasible with the most advanced carbon nanotubes found in labs. And the mass of a space elevator tether would be something like 1000 tons over 60k miles where everything above the break point would be ejected into space, so it wouldn't do massive damage in the event of a disaster. It wouldn't surprise me if we have an operational space elevator in 30 years, but it requires a *lot* of research into mass production of carbon nanotubes.

But it is very possible solar energy will be so cheap in 30 years that putting it into space would make no sense, even if the cost of launching into space was close to zero.

 

[jerry33]

The main advantages "solar in space" has is that it can work 24 hours a day and isn't hampered by trees or buildings.

 

[Yggdrasill]

The main advantages "solar in space" has is that it can work 24 hours a day and isn't hampered by trees or buildings.

True, but this challange can also be solved with for instance a global UHVDC grid. The sun is always shining somewhere, so we just need to build power lines from where the sun is shining to where it isn't shining. This is something we can do with current tech at a cost of a few hundred billion dollars.

 

[mackgoo]

I didn't read through all so sorry if someone else raised this obvious question. What does it matter how much can be collected? How do you get what ever is collected to earth?

 

[Yggdrasill]

I didn't read through all so sorry if someone else raised this obvious question. What does it matter how much can be collected? How do you get what ever is collected to earth?

The most common proposed solution is to use a huge microwave antenna. But other solutions exist, like conductive transmission though a nanotube tether.

 

[jerry33]

True, but this challange can also be solved with for instance a global UHVDC grid. The sun is always shining somewhere, so we just need to build power lines from where the sun is shining to where it isn't shining. This is something we can do with current tech at a cost of a few hundred billion dollars.

That's certainly true as long as you can get every nation with a decent amount of land area to agree. Might be harder than the "solar in space" solution though.

 

[Robert.Boston]

True, but this challange can also be solved with for instance a global UHVDC grid. The sun is always shining somewhere, so we just need to build power lines from where the sun is shining to where it isn't shining. This is something we can do with current tech at a cost of a few hundred billion dollars.

The geopolitical implications boggle the mind. I don't think China will be comfortable relying on solar arrays in North America for its nighttime power, or vice versa. Terrorist attacks on the cables alone represents an unacceptable threat level.

Even n an engineering basis, I think the Pacific Ocean creates a serious problem. There's about 7 time zones there with very little land mass.