Space solar power

Taylor Dinerman in The Space Review:

Solar power from both the Moon and from satellites would provide energy for operations in space and could be beamed down to Earth using either lasers or microwaves. The great advantage of beamed power is that it does not have to be transmitted across the giant transcontinental grids as it done today. Multiple solar power satellites, along with a large set of arrays on the Moon, would be the basis of a system that would be far more robust and reliable than our current one, which suffers from occasional blackouts such as the one suffered along the US East Coast in August 2003, or the terrorist campaign that is being carried out today against the Iraqi electricity grid.

Distributed receiver antennas (rectennas) would receive power directly from space and would be easier to isolate from a large grid than is the case with today’s large power plants. It is also the case that it would be fairly easy to replace one beam with another in case a satellite or lunar array went down.

More here.

Comments

[beajerry]

Sounds great, let's do it!

[eldarnell]

What happens if there's a malfunction and that beam of concentrated energy sweeps over a city? What about birds and aircraft? Just curious.

[Brian]

Y for y'all - I love seeing this topic come up in what passes for the mainstream.

Sounds great, let's do it!

I agree.

The real trick is that it's expensive to get stuff to orbit. While it's hard to quantify exactly how much it costs per pound - a great deal depends on which government sponsored program you use, what altitude you attain, the vehicle used, etc - the generally cited figure is $10,000 per pound.

At that rate SPS is not going to be able to compete with terrestrial power solutions no matter how nifty it is.

People are working on that - Elon Musk, Burt Rutan at Scaled Composites, etc. Even my own employer, LiftPort (space elevators!) has a long-term solutions for the cost of getting to orbit problem.

What happens if there's a malfunction and that beam of concentrated energy sweeps over a city? What about birds and aircraft? Just curious.

It's a good question. Two answers;

1) the beam is diffuse - don't think microwave ovens cooking a chicken but short radio waves. You could stand under it and not get a suntan.

Note that we've been using short radio waves for decades now for telecom transmission. So this isn't a new technology so much as a new application of an existing technology.

Still - airplane operators might prefer to not drive through the beam. Fine - declare a no fly zone around the beam.

2) A limit switch on the power-beaming widget to kill the beam if it wanders off target.

This is not so much to prevent roasting cities but to avoid lawsuits over the perception that beam wander can roast cities. Also - and this is the compelling reason - it's not economical to miss the target.

[Pete Chapman]

The part I don't get is the bit about doing it on the Moon. I can see the value in getting material from the Moon; maybe even some fairly sophisticated parts manufacturing could be done there but on the whole I'm not sure that the expenses balance out.
To be effective a series of solar arrays would have to ring the lunar equator. Either in a continuous band or an overlapping series of tracking arrays. This is a lot of real estate. There are folks, otherwise well educated who walk around with the notion that the Moon has a dark and a light side. It has an unseen side (relative to the Earth) but it has no permanently Sunward facing side.
Then there's the distance. A quarter million miles can really eat into the amount of power that you finally deliver.
My vote would go for an initial series of orbital solar arrays; getting the parts up there is a pain but nothing compared to the effort of setting up a manufacturing base on the Moon.
Of course I'm just looking at it from an off-the-shelf tech approach. Energy from space is a tempting idea when you think about the huge amount of light the Sun kicks out that literally goes nowhere.

[Brian]

The part I don't get is the bit about doing it on the Moon.

Hedging bets against which one will be more economical to operate? Anticipating power demands from non-terrestrial users? I'm not sure myself.