solar powered solar panel factory?

[ceti331]

r.e. discussions of solar power being 'economic' or not.

in the current system of trade, are solar panels are subsidized by fossil fuel energy?
to be a viable energy source, would you have to be able to 'rewind' civilization prior to the industrial revolution, and develop solar power without digging anything up.

if you could make solar panels using solar power, would they be better or worse than plants at providing for human needs.

would solar power be enough to do all the metal smelting and shaping associated with electric wires, electric vehicles etc.

can the materials for solar panels be re-cycled via a solar powered factory.
thought experiment, could you start with a solar powered solar panel factory at one corner of a desert and via self replication cover the whole thing. (or would plants already be better, i.e. dig canals for irrigation and get natures' solar-powered nanomachines re-instated)

[emordnilap]

There will come a time, not within our lifetimes, when all energy the human race has is what the sun gives, plus a little geo-thermal.

Further the thought experiment by imagining not using fossil fuels for anything at all (except getting us off them of course).

[adam2]

AFAIK there IS a PV factory that is solar powered, though that does not of course mean that all the inputs to the factory are renewably powered.

There is no reason why renewable energy could not be used for allmost all the inputs required to make PV modules.
The exception is the manufacture of iron or steel, this requires coal or coke* as carbon is part of a chemical process in iron production, not just a source of heat.

Recycling of already existing iron and steel requires a lot of energy but this could be renewably generated electricity for electric furnaces.

Power for large scale manufacturing would need vast areas of modules, much greater than the likely land area of the facility.
Such needs are best met from a large grid system, into which large PV arrays and other renewable sources can feed.
Hydroelectric power is especialy valuable in this respect as the output is readily adjusted without waste or loss.

*in theory charcoal from wood could be used, as was done at the very begining of the industrial age. In practice I doubt that enough wood could be grown

[ceti331]

very interested to hear that there IS a solar-powered-solar-panel factory

Recycling of already existing iron and steel requires a lot of energy but this could be renewably generated electricity for electric furnaces.
...
Power for large scale manufacturing would need vast areas of modules, much greater than the likely land area of the facility.
..
*in theory charcoal from wood could be used, as was done at the very begining of the industrial age. In practice I doubt that enough wood could be grown

... see, this is why i'm very fatalistic about peak oil, definitely a 'doomer'.
Does nature already not use metals because they're not good materials in the absence of fossil-fuels.

I know that electricity can be used to do anything that oil can, the question is how much will there be compared to now... how much modern tech could be kept.

i'm of the opinion all modern tech is basically 'ways of deploying fossil-fuel energy' wheras we already had very good solar-powered machines (plants)

[adam2]

Plants are indeed relatively effective means of utilising solar energy, both to feed people and working animals, and possibly as fuels for other purposes such as wood for heating, or biodiesel for machines.
Wheat, sugar, firewood, and other crops store well, unlike solar thermal or PV which can only be stores at appreciable expense and loss.

The growing of energy crops, if not done overly intensively, may benifit wildlife and bring other benifits. A properly managed wood land for example can produce building timber, firewood, and provide shelter for livestock and wildlife.

The main advantage of PV is that it need not take up land needed for agrigculture. PV modules placed atop farmhouses or barns do not reduce the area available for growing crops.
PV modules can also be ground mounted in areas unsuited to crop growing.
Wind turbines take very little ground area, some land is lost to foundations and access roads, but it is very small.
A 1,000 acre windfarm takes only a few acres out of production. To produce the same energy from coppiced woodland or oil crops would take far more land.

[ceti331]

The main advantage of PV is that it need not take up land needed for agrigculture. PV modules placed atop farmhouses or barns do not reduce the area available for growing crops.
PV modules can also be ground mounted in areas unsuited to crop growing.

these surfaces have always been available. land owners were always incentivized to maximize the value of their land
whats easier, mounting PV or irrigating, maybe growing algae in artificial containers.

i gather PV does benefit from technology improvement (manufacturing processes??), any links to good material to read to put this in perspective for me..

as far as i know the main use of PV cells was on satelites - was it a niche item that solved the problem of electricity generation under the weight restrictions of a space launch & being divorced from the earth

There's an anti-doomer picture that shows the map of the earth with 5 appropriately sized solar panel stations painted in - apparently a tiny amount needed - but i tend to think the infrastructure is more important...

[adam2]

PV modules were indeed developed largely for satellites and are still used for this purpose.
PV is not yet competitive with fossil fuels for large scale generation, but that will change as supplies deplete.
PV is already the cheapest way to produce modest amounts of electricity, for example for lighting of remote premises.
A basic PV and battery lighting system suitable for a modest sized basic dwelling would cost about £1,000.
A grid extension would cost many times that in many locations.

Even in central London, PV is cheaper than grid power for very small loads. Many parking permit machines are PV powered as the cost of the small PV module and battery is far less than a grid connection.
A new connection costs several hundred pounds.

[biffvernon]

PV is not yet competitive with fossil fuels for large scale generation, but that will change as supplies deplete.

And to illustrate this change:

The Chinese government continues to expand its clean energy production plans, to replace increasingly expensive coal power that is shutting down coal plants and causing power shortages of at least 16 GW. China’s twelth five-year plan unveiled this week plans for 70 GW for wind, and 5 GW of solar by 2015.
A new development, peak coal, has shaken up the plan. Coal prices have risen 75% since 2007, while electricity prices have only been allowed to rise 15%. Shortages of Chinese coal as local mines are depleted are driving up prices for imports (US Coal Companies Reap Windfall From Australian Climate Catastrophe) and China’s coal power plants are now under real financial stress. “Many coal plants have shut down their generators because the more they produce, the bigger the losses they will suffer,” Li Chaolin, a coal and energy industry analyst at Anbound Group told the Global Times. As a result, as much as 30 GW of power shortages are forcast as struggling coal power plants in China are unable to stay in business. China intends to build at least 75 GW of new clean energy to help supply new energy demands as its economy grows. But the dramatic loss of coal power was not factored in several years ago. China’s first CSP tender generated an average solar power price of CNY0.96 (US$15) per kWh. The price being offered for CSP solar is about double the price of its conventional coal power. Wind is also more expensive, but now increasingly competitive.

thinkprogress

[An Inspector Calls]

Peak coal in China?

Someone forgot to tell the Chinese then:
http://en.wikipedia.org/wiki/Coal

[An Inspector Calls]

Even in central London, PV is cheaper than grid power for very small loads. Many parking permit machines are PV powered as the cost of the small PV module and battery is far less than a grid connection.
A new connection costs several hundred pounds.

That depends over how long you spread the capital cost.

A grid connection should last 50-75 years. How many PV installations would you need to cover that period?

[An Inspector Calls]

And ultimately, we'll arrive at fission/fusion to see ourselves through.

[clv101]

Peak coal in China?

Someone forgot to tell the Chinese then:
http://en.wikipedia.org/wiki/Coal

Your Wiki cites a report report projecting peak coal in China in 2025.

It also suggests China's proved recoverable coal reserves are 114,500 million tonnes (12.6% world total) end 2008. That doesn't sound like a lot when you consider China's extraction in 2010 was 3,240 million tonnes (a full 9% up on the 2009) and 48.3% of world total extraction (BP 2011). If extraction stayed flat that's only an R/P of 35 years. It's not flat, it's growing fast and the actual peak will obviously occur with a large amount of coal still to be extracted.

Those reserves, that extraction rate, growing as it is, suggests peak coal in China is something we're all likely to see before long.

[ceti331]

[1] how long do the PV cells last,
[2] do economic projections that state 'pv will become economical as oil depletes' really mean "pv electricity will be less scarce than fossil-fuel electricity
[3] do these projections account for the fossil-fueled steps in manufacturing pv e.g.mining & delivering raw materials.
[4] if PV could build itself, why wasn't there a parallel economy built around them by countries or even individuals lacking oil supplies. e.g. electric trains powered by PV in sunny countries?

[An Inspector Calls]

Peak coal in China?

Someone forgot to tell the Chinese then:
http://en.wikipedia.org/wiki/Coal

Your Wiki cites a report report projecting peak coal in China in 2025.

It also suggests China's proved recoverable coal reserves are 114,500 million tonnes (12.6% world total) end 2008. That doesn't sound like a lot when you consider China's extraction in 2010 was 3,240 million tonnes (a full 9% up on the 2009) and 48.3% of world total extraction (BP 2011). If extraction stayed flat that's only an R/P of 35 years. It's not flat, it's growing fast and the actual peak will obviously occur with a large amount of coal still to be extracted.

Those reserves, that extraction rate, growing as it is, suggests peak coal in China is something we're all likely to see before long.

I thought you'd be along . . .

Well, Peak Coal will happen in China . . . but not for a while, contrary to what was said in biff's link.

The wiki link was quite explicit (thanks for your calculation though) about the reserve duration. But remember, that's only proven reserves. And as these run down they'll, rather irritatingly, go out and prove some more reserves.

[Kontiki]

I live not too far from the Sharp factory in Llay, North Wales where they produce solar panels. Don't know about the roof but they have a lot of panels on the side wall facing south'ish of the factory & also some free standing ones.