Japan proposes orbital solar farm by 2020.

[Rondon]

Its unpractical right now but if reusable rockets (via space-x for example) reduce costs significantly, it could start to become practical.

A typical 1 meter squared panel costs about $800 and weighs, conventionally 15kgs.

The benefit is that as well as getting power all day, its 44% more efficient due to not being in the atmosphere so the it provides roughly 3 times more power (2.88)

If you sent of that meter solar cells, via a space x Falcon 9 it would cost $4000 per kilogram. So, just no.

But if they manage to save the first and second stage then the cost is a tenth of the previous which out at $6000 for transport. 8.5 times the cost for 3 times the power, which is still uneconomical but this is for a conventional solar panel, a specially designed or at the very least light model combined with a light weight film for concentrating power on the cell, it could make it feasible at this stage.

And of course, if space-x ever manages to make them fully reusable and reduce the cost to one hundredth of the current price, then you're just laughing really.

[Red Iron Crown]

I really don't think recovering the first and second stage would reduce launch costs by 90%. I don't think even SpaceX's projections are that optimistic.

[Nibb31]

I think SpaceX is aiming for a 50% reduction in launch prices. I think that is highly optimistic. However, launch cost is only 20% of an average space project, so the global economy for customers will not exceed 10%. Even if it works, it will hardly be a Star Trek breakthrough.

Edited May 10, 2014 by Nibb31

[Rondon]

I really don't think recovering the first and second stage would reduce launch costs by 90%. I don't think even SpaceX's projections are that optimistic.

No, correct me if me if you have a better quote but I'm pretty sure they are:

"SpaceX has publicly indicated that if they are successful with developing the reusable technology, launch prices in the US$5 to 7 million range for the reusable Falcon 9 are possible"

http://www.parabolicarc.com/2014/01/14/shotwell/

[lajoswinkler]

People seem to live 15 years in the past regarding photovoltaic technology. A photovoltaic plant nowadays is cheaper than a nuclear plant of the same power, and they are only getting better. There are issues, like solar insolation not being constant but that's a workable technological issue, the point is that PV are competitive today in places with good insolation.

Sorry guys, you'll all have to give up your dream of a nuclear powered future (and your fusion fart unicorn if you're hoping in one too) solar power is clean and safe, and is coming to stay.

LOL

You clearly have little or no knowledge about these things. Energy sources can't be compared only by their power outputs. PV can't be used for base load power in a economically viable and reliable way. It's either coal, fission or hydroelectric.

I guess PVs grow on trees. I thought they were made in China, burping insane amounts of pollutants into the environment during the process.

[Red Iron Crown]

No, correct me if me if you have a better quote but I'm pretty sure they are:

"SpaceX has publicly indicated that if they are successful with developing the reusable technology, launch prices in the US$5 to 7 million range for the reusable Falcon 9 are possible"

http://www.parabolicarc.com/2014/01/14/shotwell/

That's quite a claim, here's hoping they can achieve something close to it. It also ignores the reduced payload of the reusable F9R, so while an individual launch may be 1/10th the cost, the price per kg to orbit would be reduced by a lesser percentage. Still great if they can achieve it, but I consider it unlikely.

[Nibb31]

No, correct me if me if you have a better quote but I'm pretty sure they are:

"SpaceX has publicly indicated that if they are successful with developing the reusable technology, launch prices in the US$5 to 7 million range for the reusable Falcon 9 are possible"

http://www.parabolicarc.com/2014/01/14/shotwell/

What a PR person claims and reality are often different things. It may be possible in a few century or two with a fully reusable launcher, totally different technology, and much higher launch rates, but the F-9R as we know it is incapable of reducing launch costs by 90%, unless constructing the 1st stage hardware represents more than 90% of the cost of launching the rocket. Hint: it doesn't.

On the other hand, reusable hardware means less units to produce which means higher cost per unit. It means less workers are needed for the actual production work, but it doesn't cut any of the other costs for recovering, handling, sourcing, testing, processing, integrating the hardware. It also does nothing to reduce development, administration and facility support costs.

The only thing that will lower the cost of launching things into space is demand. When there will actually be demand to launch once or twice a week, then costs will mechanically come down. Whether it happens through reusability, mass production, cheaper processing, or lower wages doesn't really matter because the market will find a way. The key is actual demand, not technology.

Edited May 10, 2014 by Nibb31

[Rondon]

That's quite a claim, here's hoping they can achieve something close to it. It also ignores the reduced payload of the reusable F9R, so while an individual launch may be 1/10th the cost, the price per kg to orbit would be reduced by a lesser percentage. Still great if they can achieve it, but I consider it unlikely.

Musk's statement is that the payload is reduced by 30%, I don't see any real problem with the first stage being recovered aside from actually doing it, but that second stage would be a challenge.

Edited May 10, 2014 by Rondon

[rkman]

Hear that? That's the sound of your credibility imploding into a singularity.

An orbital solar power plant has

Isn't it interesting how people talk in the present tense, as though it exists now, about things that do not exist.

LOL

PV can't be used for base load power in a economically viable and reliable way. It's either coal, fission or hydroelectric.

Because there is no way to store electric energy?

Nevada's New Molten Salt Solar Plant Will Produce Power Long After the Sun Sets

http://inhabitat.com/nevadas-new-molten-salt-solar-plant-will-produce-power-long-after-the-sun-sets/

How to Use Solar Energy at Night

Molten salts can store the sun's heat during the day and provide power at night

http://www.scientificamerican.com/article/how-to-use-solar-energy-at-night/

Gemasolar

http://www.torresolenergy.com/TORRESOL/gemasolar-plant/en

Edited May 10, 2014 by rkman

[Rakaydos]

Ground based solar is unsutible for base load, but space based solar is. In geosynch "night" only lasts 4 hours, someone said, so instead of being screwed by a cloudy day, the price of electricity simply jumps between 11 PM and 3 AM.

The "death beam" cant warm a cup of coffee, but they stick enough antennas in the beam to generate significant power anyway. And the recever sends a homing beam back to the satelite so it CANT get lost. And it's being built on an artificial island, so if it DID get lost nothing else is in danger.

[Red Iron Crown]

The "death beam" cant warm a cup of coffee, but they stick enough antennas in the beam to generate significant power anyway. And the recever sends a homing beam back to the satelite so it CANT get lost. And it's being built on an artificial island, so if it DID get lost nothing else is in danger.

I think the greater danger is the interruption in power supply if the beam goes off target. All depends on how reliable the system can be made.

[rkman]

Ground based solar is unsutible for base load

Why is that? See my previous post as to why it is not so.

[Seret]

Base load generators are on fixed price contracts Rakaydos, and it's a very low rate. That's why any space based power station will be uneconomic while the cost of lifting mass to orbit remains high. The extreme capital costs would put your cost per kWh well above what you could earn.

That's why every time it's been looked at it's been decided against. As others have said, spending the same amount on a ground mounted array would generate a lot more power overall.

[Seret]

Why is that? See my previous post as to why it is not so.

Base load requires a system that can generate very reliably for very low cost. Adding enough storage generally makes solar power uncompetitive except in areas with very high isolation and low land values, where solar thermal becomes viable.

[Seret]

I think the greater danger is the interruption in power supply if the beam goes off target. All depends on how reliable the system can be made.

That's no more of a problem than any other generator going offline. Grids are generally run with enough spare capacity to deal with a major thermal plant dropping out without warning.

[Red Iron Crown]

That's no more of a problem than any other generator going offline. Grids are generally run with enough spare capacity to deal with a major thermal plant dropping out without warning.

That's true, but it is much more challenging to effect repairs/adjustments to something in orbit.

[Rakaydos]

That's true, but it is much more challenging to effect repairs/adjustments to something in orbit.

Which is why most satelites seem to be able to function while half-dead, because we can still squeeze a bit more use out of the investment. Unless a perfect edge-on hit completely kesslerizes the array, the satelite should be able to beam down at least SOME power until they can send up replacement panels.

[The Jedi Master]

Turn up the power of your car engine, and you have a fuel air bomb! And one that makes a hydrogen bomb look like a firecracker. Imagine if an accident happened, and it took out a city. Not in my neiborhood!

If you read the article, the beam couldnt even warm a decent cup of coffee.

Well, when you put it that way...

Still, when you put away the exaggerations (I am often guilty of exaggeration ), it's still a powerful, dangerous piece of equipment. Think of it like the sun (that's basically what it's harnessing, after all). It can burn you to a crisp, but you are too far away to get that. It doesn't mean that it doesn't still have that power.

[Seret]

Well if you think about it, all power stations contain potentially dangerous levels of power. Kind of goes with the territory.

[rkman]

Base load requires a system that can generate very reliably for very low cost.

I think space based solar farming is neither.

[KSK]

What a PR person claims and reality are often different things. It may be possible in a few century or two with a fully reusable launcher, totally different technology, and much higher launch rates, but the F-9R as we know it is incapable of reducing launch costs by 90%, unless constructing the 1st stage hardware represents more than 90% of the cost of launching the rocket. Hint: it doesn't.

On the other hand, reusable hardware means less units to produce which means higher cost per unit. It means less workers are needed for the actual production work, but it doesn't cut any of the other costs for recovering, handling, sourcing, testing, processing, integrating the hardware. It also does nothing to reduce development, administration and facility support costs.

The only thing that will lower the cost of launching things into space is demand. When there will actually be demand to launch once or twice a week, then costs will mechanically come down. Whether it happens through reusability, mass production, cheaper processing, or lower wages doesn't really matter because the market will find a way. The key is actual demand, not technology.

It's the old chicken-and-egg problem though isn't it? There's limited demand because launch costs are so high but because there's limited demand, launch costs have remained high. Whether cheaper launch costs will manage to break that cycle remains to be seen but all credit to SpaceX for giving it a go.

[cantab]

Presumably they're looking for something to replace nuclear for base load generation. I remain unconvinced that SPSs can provide base load economically. Base load is a fixed contract, but the price per MWh is rock bottom. PV isn't economical for base load at ground level, and going to orbit only improves insolation by a bit over 30% per unit area, and a bit over double in terms of time. You just aren't going to get enough of a performance increase to make lifting all that mass into orbit economical. The cost of the receiver would be considerable too, due to the amount of area it would take up.

Would orbital photovoltaics not be viable for meeting peak loads, something that's worth more. I believe solar cells don't suffer any adverse effects from being exposed to sunlight with an open circuit (correct me if I'm wrong), and the reciever is all electronics, no mechanical parts to spin up, so if power is needed the orbital station could come online as quickly if not quicker than hydro (the current go-to for meeting load spikes).

I still doubt it will be commercially viable without a significant drop in the cost of launching mass to orbit mind. But it might be that Japan sees it as a strategic asset, and compared to more regular military expenses it'll probably be pretty affordable. At the very least, I wouldn't be surprised to see an operational pilot plant.

Japan would be better of using (more?) of its very long coast line for tidal power.

The tides are really weak on most of said coastline, though there are some decent bits: http://en.wikipedia.org/wiki/File:M2_tidal_constituent.jpg

Or geothermal. Being on a fault line with active volcanoes sometimes has some advantages.

Not many volcanoes in Japan, and IIRC subduction zones actually give reduced geothermal heat flow, since the cool ocean plate is being pushed down replacing the warm asthenosphere.

The scale of these things would mean debris is a constant problem, which would mean constant repair/part replacement missions, which would mean a neverending stream of launches, each costing - even in the most optimistic of scenarios - millions of dollars.

I think it would have to be designed to be damage tolerant. Sure, over time the micrometeorite hits will damage cells and thus reduce power output, but the whole thing stays operational. The expensive bit might be decommissioning; if the mechanism to fold the thing back up compactly fails (because I'm assuming you aren't just going to stick it in a graveyard orbit still at its full huge size) then there may need to be a manned or robotic servicing mission to sort things out. It may also be possible to design it to minimise cascade effects from micrometeorite hits so it doesn't produce more debris. Transparent whipple shielding over the cells perhaps?

[1D-1()T]

Sorry if this has already been mentioned, but I thought I'd just pop in and say a few words.

The way I see it is that sending stuff into space is always going to be damn expensive, so you'd better have a solid reason to do so. In most situations solar panels are not a solid reason. In a country like Australia, where you have a ridiculous amount of sunbaked land, and for the most part no good use for it, why would you send solar panels into space. Japan admittedly does lack space, and I don't really know about its weather, so solar panels in space might be the best option. But that is just solar panels. There are many other sources of energy that are not only cheap (once established), but relatively clean, which they could instead use, such as wind farms, the tides, or geothermal. Most, if not all, production could occur off shore, thus saving space.

A possible use for orbital solar panels, which I heard of in the book Colonies in Space(google it if you're interested), is as a source of revenue when establishing infrastructure in space. The idea of it seems to be that, while such infrastructure is being expanded, the existing framework should be put to use, in this case making solar satellites. This provide jobs for workers, power on earth, revenue for the venture, and provides a good test of their capabilities.

[hasty6]

I watched a program about solar arrays in space and they said that transmitting the electricity back from space using microwaves is insufficient. They said that even a small bit of cloud cover can almost completely block out the microwave signal and because of the natural resistance of the atmosphere you would be loosing lots of electric charge on the way making it inefficient.

[Nibb31]

It's the old chicken-and-egg problem though isn't it? There's limited demand because launch costs are so high but because there's limited demand, launch costs have remained high. Whether cheaper launch costs will manage to break that cycle remains to be seen but all credit to SpaceX for giving it a go.

You're partly right, but I don't think that cheap launches will increase demand. Even dividing prices by 10 will not cause launch demand to multiply by 10.

Demand is created by purpose. There needs to be a reason to put stuff in space. Space needs new applications with a decent return on investment or at least some sort of incentive. The only economically viable space activity right now is comsats. Even if SpaceX was capable of cutting launch prices from $70 million to $7 million, it won't make new applications appear out of thin air.

Edited May 13, 2014 by Nibb31