The big question..

[4dsc]

http://zone5.org/2007/05/14/peak-opportunity-2-energy-literacy/

Oh this is a good question we all can start asking ourselves(and no, ethanol will not be the answer)..

When introducing the concept of Peak Oil and explaining what implications it will have I like to start with an image of renewable energy, but I suspect that that phrase will conjure up for most people images of photo voltaic panels or wind-turbines rather than a horse. David Holmgren has pointed out that in the 30-odd years PV panels have been being developed, the technology has approached the level of efficiency of plant chloroplasts (somewhere in the region of 20% )- a stunning achievement given that plants have taken millions of years to evolve to this stage. We might guess from this however that this level of efficiency is perhaps the most that will ever be achievable by this technology, and not put too much hope into further leaps in this kind of technology.

Solar panels require both expensive materials and fossil energy in their manufacture. In one sense, putting a solar panel on your roof is really the same as sticking a large barrel of oil on the roof- far from being a source of “free” or even truly “renewable” energy, photovoltaics, like windturbines and many other forms of “renewable energy” are just more efficient ways of using or effectively storing fossil energy. A big question is, when solar PVs come to the end of their life in 20-30 years, will society have the resource to make new ones?

In the long run technology of this kind will always lose out to biological resources like horses which have the capacity to reproduce themselves.

Interesting when you think about the fact that our society will not have the oil in 30 years to produce more solor panels the way we do today.

[NMDemDist2]

1. I'm really thinking I need to get a pony and cart

it's only 6 miles into town, that would only take 90 minutes one way eh?


I could do that :rofl:

[muriel_volestrangler]

15. You can walk 6 miles in 90 minutes (n/t)

[Nihil]

16. Not if you're carrying a pony! (n/t)

[GliderGuider]

17. Not if you're 70 years old with arthritic knees.

Or carrying a baby, or escorting two children under the age of 5.

The argument that "we can simply walk or bike" founders on the fact that this applies to only a small segment of the population - those who are in good health and physical condition, and are travelling short distances more or less unencumbered.

[ramapo]

20. The tragedy of suburbia

Never mind the exhurbs. We've built our society around an infrastructure that makes the idea of walking seem silly, even dangerous, to most people. Even sidewalks are seen as a nasty governmental intrusion.

I grew up, and have lived my life, in North Jersey. Not that very long ago (40-45 yrs), it was possible to exist without a car in much of the area. There were local grocers and other small shops. Buses would take you to the urban hubs like Paterson. Sadly train service had already disappeared and the trolley system which had once existed was long gone. But walking was a feasible transportation system to meet much of your needs.

Now walkers are looked upon almost as loonies. Kids don't walk to school for a variety of reasons, too far, too dangerous, too lazy.

[The2ndWheel]

21. Well typed

In a society not built for humans, humans end up being helpless.

[NMDemDist2]

19. yeah, but I can't carry the groceries or whatever back n/t

[dave_p]

2. Let's slow oil exhaustion first

Energy efficiency's part of the answer. Then you get more time to work on replacement technologies. Who knows how PV's will be produced in 20-30 years? But the more time we give ourselves through conservation, the more time we have to come up with the answer.

[jpak]

3. The answer is yes

PV modules are manufactured using aluminum, polySi and glass - some (like Schott) modules do not use traditional EVA encapsulation.

Aluminum and silicon are among the most abundant elements in the Earth's crust.

Aluminum can be smelted using geothermal, hydroelectric, large scale wind or biomass electricity - (think Iceland and US Northwest).

Same for glass, metallurgical Si and PolySi manufacture (again think US Northwest).

Solarex (now BP) uses PV electricity at its "Solar Breeder" PV plant in Fredricksburg MD - it's been in operation for over 2 decades.

Furthermore, with the exception of the EVA encapsulation, every bit of a PV module is recyclable - and can be used to manufacture new PV modules at a fraction of the de novo energy cost.

Not a problem in the post-Peak economy.

[NNadir]

5. Solar power can't even power the servers for the websites now running to promote it.

Now it's going to make aluminum?

Don't make me laugh.

In the Pacific Northwest alone, aluminum manufacture requires more than 3,000 MWe, and that's not bullshit "peak" watts available for a half hour at noon on a sunny day. That's <em>continuous</em> 24/7 watts including watts at midnight.

http://www.nwcouncil.org/library/2002/2002-20.pdf

Note that even hydroelectric is too expensive and it's 1/20th of the cost of solar PV.

You've been here 4 years now telling us how solar was going to become affordable.

Guess what? It's not.

Solar energy is a failure. It has not shut even one natural gas plant on earth, nor will it ever do so. Twenty years from now, the existing solar cells will be transformed into electronic waste piled in landfills and you'll be telling us about renewable energy targets in 2070. In the meantime of course, much of earth's habitat will be destroyed while you fiddle.

[arenean]

12. Aluminium

There's no way that aluminium (sorry, 'aluminum' for everyone in the US!) from PV cells that have reached the end of their life cycle, will be allowed to pile up in landfills. Aluminium is the single best material to recycle - recycling saves 95% of the energy in manufacturing Al from virgin materials.

[NickB79]

13. Without the energy to melt it, it's practically worthless

If I gave you a 100-lb boulder that was composed of 25% gold dust but no one has any way to smelt out the gold, what's it worth?

[Javaman]

23. Maybe if we just all stare at it really hard. LOL nt

[Kolesar]

24. It's an aluminum extrusion, not a 100 pound boulder with some metal dust in it

The huge energy involved is the initial refining of the aluminum ore. Recycling uses a small fraction of that energy.

[OKIsItJustMe]

28. Recycling aluminum requires 5% of the energy it takes to produce it

http://en.wikipedia.org/wiki/Aluminium_recycling

[jpak]

29. Again - there is plenty of geothermal and hydroelectric capacity to smelt aluminum

It is no coincidence that most US Al smelters are located in the Pacific Northwest (i.e., large amounts of cheap hydroelectricity).

Iceland is rapidly becoming a world leader in geothermal power production for Al-smelting.

The same can be done with glass and poly-Si at smaller scales.

The renewable energy needed to produce the world's demand for PV is available today.

It is not a problem.

[NickB79]

43. So let me get this straight

You advocate using up the electricity from a source that operates 24/7, day and night, to build solar panels that only operate during the day at a 20-30% efficiency level? Why not just use the electricity from the hydroelectric and geothermal sources directly by feeding it into the grid?

"The renewable energy needed to produce the world's demand for PV is available today."

That's not really encouraging because the CURRENT demand for PV is a tiny percentage of global energy production (as NNadir asks, where's the first exajoule of solar power?). We're discussing 30 yrs down the road from now, when natural gas, oil and coal supplies have all peaked and are in decline. For example, a large portion of the hydroelectric and geothermal power sources in the Pacific Northwest will probably be required to replace the electricity no longer generated by natural gas-buring turbines idled from lack of fuel.

[jpak]

47. Yes - a handful of large geothermal and/or hydroelectric plants could be used to

mass produce PV modules on a sustainable basis.

That was the original question in the OP.

With existing storage and grid management/support technologies, that new PV capacity can produce electricity *on demand* 24/7 world wide.

Futhermore, wind power, biomass and wave power plants backed by existing hydroelectric capacity will replace natural gas-fired plants in the NW...

http://www.washingtonpost.com/wp-dyn/content/article/2007/03/20/AR2007032001634_pf.html

edit: better link

and they're building some beefy PV arrays out that way...

Rainy Washington pursues solar power

http://seattlepi.nwsource.com/local/6420AP_WST_Sunny_Washington.html

ELLENSBURG, Wash. -- Gray, gloomy rain. As much as Mount Rainier and salmon, drizzle is the staple image of the Pacific Northwest. The city of Seattle even broke a record last fall for precipitation in one month.

But east of the Cascade Range, where sagebrush blooms in a desert climate, power companies see potential in sunshine. Washington state's oldest utility plans to start building the largest solar project in the region next month, and a municipal utility in a small city known most for its rodeo is enlisting residents' help to expand its energy generation through the sun.

Already, communities up and down the West Coast are taking notice of a trend dampening notions about the Pacific Northwest.

"Yes, it's not as good a deal in a state that gets less sun as it is in a state that sees more sunlight," said Stephen Frantz, a program planner for the Sacramento Municipal Utility District. "To compensate for that, you just have a strong environmental ethic in the Pacific Northwest."

<more>

[OKIsItJustMe]

22. Check out these curves

Anyone who understands a bit of mathematics can see what these curves imply for future growth.

[NNadir]

35. Really? You mean at peak of day, all the world's solar equals one small coal plant?

How long does all the world's solar power manage that?

15 minutes?

12 minutes?

Like I said, the servers used to promote solar energy consume more electricity than solar energy can produce.

Learn some math, just a little, a tiny bit.

Here let me help you. Fifty years after the invention of the solar cell according to second graph, solar power's installed peak capacity was about 2600 MWe. Since the capacity utilization of solar power plants is about 20% (in deserts) this number should be divided by 5 to compare to a continuous power plant. That makes the solar plant for the entire planet equal to about 520 MWe, one small gas plant. Translated once again, although you continuously mislead on this point, into units of energy, using the 0.20 capacity utilization, the entire planet's solar installations produce 0.016 exajoules of energy out of the 470 exajoules used on the planet.

Thus solar energy is a failure, especially when one considers how much energy is used in websites to promote it.

In 2005, servers are estimated to have consumed 123 billion kw-hrs of electricity or about 0.44 exajoules. Thus after 50 years of continuous loud-mouthed talk, solar electricity barely provides enough energy to power 4% of the world's computer servers.

Tell us again how it's going to produce aluminum?

Tell us once more after that?

Tell us every day for the next 4 years, just like you've told us every day for the last four years. It will still be a line of shit.

[OKIsItJustMe]

44. "Exponential Growth"

Those are two words which you seem unwilling to acknowledge.

Once a curve begins to show signs of exponential growth, look out.

If a solar cell only produces 20% of its theoretical potential, who cares? You're talking about an arithmetic failing. So long as it's a significant fraction, exponential growth takes care of the rest.

[NickB79]

45. I knew a guy who spoke that way about the housing market

Didn't work out so good for him.....

[jpak]

27. Delusional nonsense - as usual

Here's a net energy analysis of Solarex's Solar Breeder...

http://adsabs.harvard.edu/abs/1978pvsp.conf..908W

Solarex's Solar Breeder PV production plant has been in operation since 1982.

http://www.humboldt.edu/~serc/refaqs.html

note: unlike the made-up NJ molten salt breeder reactor - the Solarex plant is "real".

Global PV production is growing exponentially at double digits per year - it's a lucrative *rapidly* growing multi-billion dollar per year business.

Global installations of PV now exceed 6 GWe - and produce much more electricity each year than a "single natural gas plant".

Solar thermal installations currently exceed 13 GWt - that's equivalent to the thermal output of four 1000 MW power plants.

http://gsr.ren21.net/index.php?title=1._Global_Market_Overview

Last year, global PV production exceeded 2200 MW and Germany alone installed 920 MW of PV.

Multi-MW PV arrays are in operation in Europe and Asia and under construction here in the US.

The claim that "Solar power can't even power the servers for the websites now running to promote it." is laughable nonsense and false.

Solar is not "a failure".

Solar - not nuclear - is the future and the savior of the planet.

[Kolesar]

31. How "old" would you say solar PV technology is?

I would say that nuclear is 47 years old because the first plant on the grid was Shippingport, PA, 1960.

My start date on PVs would be at about the time thin-film PVs came on line. Those were not dependent upon the scrap silicon wafers from the microelectronics industry. At that time, the PV industry hit a good price point and had a technology that was scalable to "any" size.

My point here is that nuclear has had a forty year lead time on PV electricity. One could not have expected more delivered power from PVs than what we have now because the industry is just starting now.

The starting point was not some time in the 1960s when PV technology was used on the Mercury, Gemini, and Apollo space missions.

[jpak]

32. For off-grid commercial/residential purposes about 25 years

For grid-connected applications, less than 10 years.

That's when German and Japanese solar roof programs and US state solar rebate programs, net metering laws and RSPs were enacted (and many state's still don't have them).

Congress reinstated homeowner solar tax credits in 2005 - 23 years after St. Ronnie and the anti-solar GOP eliminated them - and they have been available for only a year now.

The US solar industry is just now emerging from the GOP Dark Ages...

[Kolesar]

33. Still a young industry compared with plants that have been online for 30 years like Davis Besse

... plants that were deployed after decades of development and billions of dollars of taxpayer money.

[Name removed]

37. Deleted message

Message removed by moderator. Click here to review the message board rules.

[Name removed]

36. Deleted message

Message removed by moderator. Click here to review the message board rules.

[Kolesar]

42. Efficiency is a better investment than nuclear. Now, *you* should invest in some anger management,

..Mr. Reflexive. Funny that you would say reflexive because it appears that you don't read my posts. You don't even know what my position on nuclear energy is.

BTW, you have already used/wasted page space with your Bell advertisement on previous threads.

And your "cut down shade trees to put solar cells on the roof" anxiety attack.

I expect your forum "camp follower" to be here soon to restate your position with less profanity but equal the ire.

[jpak]

46. My bad - Solar thermal installations are currently 13+ GWt *per year*

Global solar thermal installations currently exceed 88 GWt which is equivalent to the thermal output of twenty nine 1000 MW nuclear plants.

[TheWraith]

4. No worries, it's never going to happen.

Our society isn't so fragile as some people seem to think. Cheap, abundant natural oil is a convenience, which enables us to skip a few steps in certain things, but it's not a neccessity. Most of our technology doesn't need fossil fuels, it just needs energy: see electric cars, et al. The remaining sectors can either be retooled or supplied using synthetic petroleum products. The fact that some people create a fantasy world where we're going to revert to the technology of 200 years ago doesn't change that.

[4dsc]

6. Technology doesn't need oil???

How are you going to make your technology work without oil??

[Massacure]

9. oil can be synthesized. We just need energy. Society needs energy, not oil.

[GliderGuider]

18. Oil cannot currently be synthesized at the rates required

Oil synthesis (e.g. CTL via Fischer-Tropsch) is also an extraordinarily dirty process.

The key questions to ask about any liquid fuel replacement proposal are: what is the net energy, what is the possible rate of production, and what are the externalities of production (e.g.. water requirements, soil depletion and residual pollution)?

Yes, we need energy, but more than anything oil gives us ubiquitous, cheap, flexible long distance transportation - something no other energy carrier can provide. If you believe that such transportation is essential to modern industrial society, the decline of oil is profoundly worrying. If you don't believe it's essential, you haven't been paying attention.

[Javaman]

25. Why did you have to go and ruin his bizarre hyperbole with facts?

:rofl:

[TheWraith]

49. We don't need to synthesize paleo-petroleum.

For instance, kerosene to power our aircraft fleets can be easily produced from almost any kind of oil--it was originally derived from waste oils, back in the days when it was just used in cooking and lamps. Every day in this country, vast amounts of oil of all types goes to waste, from sources natural, plant, and animal. The same goes for most of our other essentials--either it can be replaced by other technologies, or we simply synthesize the materials needed. Cars and trucks don't require liquid fuel, they require better batteries. Even today, with no new advances, we can produce vehicles going 200 miles on a charge, which is more than enough for most people.

A decline in paleo-petroleum wouldn't be any more crippling to our civilization than the decline in whale-oil use was.

[4dsc]

52. YOu're not thinking to scale

While there may be "vast amounts of oil of all types goes to waste, from sources natural, plant, and animal", what you're missing is the scale of the problem.. No amount of waste or what ever alternative you can mention, will be able to replace a faction of the energy we get from oil!!

[GliderGuider]

53. Look at the scale of usage and probable depletion rate

We use 84 million barrels of oil a day. 70% of that is used for transportation. 98% of all transportation currently runs on oil. A reasonable expectation for the post-peak oil supply decline rate is 3% per year. That means that each year we will need to replace an additional 2.5 million barrels of oil. After ten years of this decline we would need to have replacements for almost 30% of the oil supply, or about 25 million barrels of oil per day.

Let's look at some reasonable expectations for mitigation.

Some of that will come from conservation. Let's say personal transportation demand reduction and moves to public transit by rich people in rich countries takes care of 20% of that. Some change of industrial transportation to electric rail will help - another 20% seems reasonable. Personal battery vehicles will take up some of the slack, but only in rich first-world nations because the capital outlay (especially over a 10-year window which is shorter than the global vehicle fleet replacement time) will be too great for the poor to absorb. Let's say that replaces another 10% of the lost oil. We've now taken care of 50% of the unfilled requirement. What are the possibilities for absorbing the remaining 50%, or 12.5 million barrels per day of oil equivalent? Biofuels will take care of maybe another 5% (and I think this is excessively generous). The remaining 45% (over 11 Million barrels per day, for 13% of all global transportation) will come from demand destruction - poor people will simply no longer be able to travel. Actually, personal travel will be hit harder than that, because oil will be allocated preferentially to higher-value commercial transportation, like food and manufactured goods.

Now this is the picture after only 10 years of a 3% oil decline. There are two further things to consider. First, the situation never stabilizes. In 20 years, it will be twice as bad, with over a quarter of all global transportation being out of service. Second, the 3% per annum decline in oil supply is probably excessively conservative. A senior Iranian oil scientist has issued an estimate that we will lose 35% of the global oil supply over the next 13 years, with an accelerating decline rate over that time, passing through 5% per annum by 2020 and continuing to climb.

The scale of the problem is vastly greater than you have comprehended.

[Dogmudgeon]

7. But getting there will be the trauma

First, I think it is indeed possible that our civilization could completely collapse -- just not probable. None the less, since we're rushing headlong into the transitional era without many options in place or contingency plans made, there is (likely) going to be a hell of a lot of suffering.

I am also convinced that when the price of oil has become punitive, we will immediately turn to coal and coal gasification, which is analogous to a marijuana smoker deciding to break the habit by switching to black tar opium. (And speaking of tar, those Athabasca and Orinoco asphalt deposits will look mighty tempting, too.) I'm not sure where you stand on the issue of nuclear energy, but either way, just the radioactive material put into the air by burning coal is in the thousands-of-Chernobyls-per-year range (assuming twenty tons of vaporized uranium released by Chernobyl). A dramatic increase in coal combustion will jack that quantity way up.

The fantasy world that really bugs me is the bourgeois Euro-American fantasy that when the feces hit the fan, all the "advanced" (i.e., affluent) people will retreat to solar- and wind-powered vegetarian neo-pagan communes and enjoy a cozy apocalypse while the icky fat people will die well-deserved deaths in their SUVs, burgers in their mouths, and copies of Ann Coulter's latest screed open beside them.

I suspect the reality will be more like the economic collapse that hit central Europe in the Great Depression -- only worse, and lasting 50 years.

I hope, strongly, that I am wrong. I would prefer an orderly re-organization of the way we do things, then get back on track to building the kind of civilization that will some day take us to the stars instead of a mass grave.

--p!

[TheWraith]

50. Perhaps.

"there is (likely) going to be a hell of a lot of suffering."

Possibly. I tend to feel, though, that as a species we've got a pretty good survival instinct. We've managed to avoid all of our previous opportunities for self-destruction, fixed the ozone layer, and our technology is now developing to a point that will make it easier and more desirable than ever to put away fossil-fuel based systems.

"I'm not sure where you stand on the issue of nuclear energy, but either way, just the radioactive material put into the air by burning coal is in the thousands-of-Chernobyls-per-year range (assuming twenty tons of vaporized uranium released by Chernobyl)."

Which is one reason why I find the paranoia over nuclear power to be highly amusing. Fission reactors aren't my favorite things, but I'd take one of them over a coal plant any day of the week, and twice on Sundays. I think all the people who have been screaming bloody murder over even the idea of expanding nuclear power have been doing everyone a massive disservice, and have helped hasten air pollution and global warming. They conveniently ignore the fact that air pollution kills 5-10 times the number of people in this country as were killed by Chernobyl--every year. When you're talking about risk/reward trade-offs, the answer seems pretty obvious.

Although, if Dr. Bussard's research pans out the way he seems to think it will (and assuming he can get the $200 million to fund it), we may be looking at viable fusion reactors in fifteen or twenty years, which would basically offer the benefits of nuclear with very little risk.

"The fantasy world that really bugs me is the bourgeois Euro-American fantasy that when the feces hit the fan, all the "advanced" (i.e., affluent) people will retreat to solar- and wind-powered vegetarian neo-pagan communes and enjoy a cozy apocalypse while the icky fat people will die well-deserved deaths in their SUVs, burgers in their mouths, and copies of Ann Coulter's latest screed open beside them."

My pet peeve is very similar, being the obsession some people here have with a vision in their mind of a perfect world being some kind of idealized 1840s farmer life, minus all the icky bits of actually having to do the work, and the realities of what that kind of life was truly like. I think that if the people who advocate that sort of thing actually tried it as a basis for their own survival, they'd either quit or starve. As much as change may frighten some people, trying to regress or create some kind of bubble-world isn't the solution.

I think that in the long term, we're going to make it without massive disruption. Things will change, and there's no guarantee it will always be convenient, but that's progress.

[skids]

8. We might guess?

"We might guess from this however that this level of efficiency is perhaps the most that will ever be achievable by this technology, and not put too much hope into further leaps in this kind of technology."

We might guess from the above comment that the author has his head completely surrounded by sphincter. They broke 40% what, two years ago?

[NNadir]

10. And the first exajoule is when?

How about 40% of the first 1% of the first exajoule?

[OKIsItJustMe]

26. November 18, 2002: An unexpected discovery could yield a full spectrum solar cell

http://www.lbl.gov/Science-Articles/Archive/MSD-full-spectrum-solar-cell.html

BERKELEY, CA — Researchers in the Materials Sciences Division (MSD) of Lawrence Berkeley National Laboratory, working with crystal-growing teams at Cornell University and Japan's Ritsumeikan University, have learned that the band gap of the semiconductor indium nitride is not 2 electron volts (2 eV) as previously thought, but instead is a much lower 0.7 eV.

The serendipitous discovery means that a single system of alloys incorporating indium, gallium, and nitrogen can convert virtually the full spectrum of sunlight -- from the near infrared to the far ultraviolet -- to electrical current.

"It's as if nature designed this material on purpose to match the solar spectrum," says MSD's Wladek Walukiewicz, who led the collaborators in making the discovery.

...

More Here:
http://www.lbl.gov/msd/PIs/Walukiewicz/02/02_8_Full_Solar_Spectrum.html

[XemaSab]

11. Horses are a shitty technology and that's why they've been replaced

I know a few people who own horses, and the fossil fuels used to feed the horses... it's more than you would think.

Horses are prone to diseases and injuries, in addition to being dangerous to ride and handle.

Feeding horses on a large scale will cause a great deal of environmental damage. How many horse paddocks have you seen? They totally denude the vegetation when kept in areas that are too small.

We will never revert to using horses.

[hunter]

38. I use horses as my Reductio ad absurdum

Maybe I should use hamsters?

:hi:

[XemaSab]

40. Hamsters are easier to handle

:D

[Nihil]

41. I've never had a problem with a horse hiding behind my bookcase though ...

:hi:

[hunter]

51. So I was trying to figure out hamster power

1 kilowatt = 1.34 horsepower = ? hamster power,
and believe it or not, people have been working on this novel alternative energy source.

Hamster-Powered Night Light With Custom Low-RPM Alternator

http://www.otherpower.com/hamster.html

[NickB79]

14. Building or recycling solar panels will be difficult in an economy built on cottage industry

If the peak and decline is anywhere near as bad as some feel it will be, most major ways of doing business will cease to exist. People will be forced to buy locally of produces made locally, hence the reference to cottage industry. Massive, energy-intensive manufacturing operations will likely be few and far between as their costs to operate will be staggeringly high, and there will be few people with the wealth to purchase what they're making. Solar panels, along with most other forms of high-tech gadgetry we've grown accustomed to, will be very, very expensive to produce, even if they can be recycled.

I don't see a cottage industry of locally produced solar panels popping up anytime soon, so I don't think solar panel production or recycling will be a major part of the Post-Peak era. I'm sure there will be much work invested into keeping what we already have working as long as possible, but newly manufactured goods will be quite a bit more scarce than they are today.

[jpak]

30. Grupo Fenix established "cottage industry" PV module manufacture in Nicaragua years ago

http://www.thesustainablevillage.com/partners/fenix2.html

note: Richard Komp is president of the Maine Solar Energy Association...

http://ellsworthme.org/MESEA/

[NickB79]

34. At first I thought this completely disproved what I had posted

Then I saw this just reading the first link:

"Except for the solar cells and some other special electronic parts, the entire system is made in Nicaragua from local parts by these pioneers."

So, except for the actually solar cells, the Nicaraguans can make solar panels themselves? :freak: The key component of the solar panel is still manufactured in the US. It also says nothing about the Nicaraguans ability to recycle these panels when they eventually die and build brand new ones from the pieces, which was the original posters question.

Then I also saw this statement:

"The farmer still pays the major part of the approximately $500 installed system price."

A quick googling found that the average annual income in Nicaragua is $430/yr. Even subsidized this program still costs per farmer more than he or she likely makes in a year, despite the fact they use discarded and rejected solar cells they get at a bargain from overseas AND use locally manufactured parts for the wiring, lighting and batteries.

[jpak]

48. Sorry for the late reply - yesterday's serve problems wouldn't let me post...

No one is going to cobble together PV modules with rocks and sticks.

The processes use to produce met-grade Si and polySi, however, are highly scalable.

The first PV cell plants were tiny (a few MW per year) compared to today's plants that will soon will produce 700-1600 MW of cells per year (individually).

The Solarex Solar Breeder used a 200 kW PV array - huge when it was built in 1982, but small by today's standards.

A small (<1 MW) hydroelectric or biomass plant could run it 24/7.

That's not cottage industry scale - maybe village or town industry scale.

Finally, Grupa Fenix established a micro-loan bank to fund PV purchases in Nicaragua. Buyers don't shell out the costs up front, the payments are made over many years and easily replace the cost of kerosene for lighting.

[lumberjack_jeff]

39. Is it more efficient to use the sun, water and fertilizer to grow plants..

...then feed them to the horses which can then be hooked to a machine to do occasional useful work, or is it more efficient to feed the plants directly to a machine?

The plant-powered (vegetable oil or wood burning) machine only runs when you need the work. The horse eats all the time.