Monday, April 27, 2020

Review of the documentary Planet of the Humans

Comments on and review of the documentary Planet of the Humans
which was just released by Michael Moore, mostly done by Jeff Gibbs with some by Ozzie Zehner.

April 26, 2020, updated April 28, 2020

update April 28, 2020
A great review and collection of other review is at Films For Action

I feel even more outraged, I believed the film when it was talking about Bill McKibben and thought "well, at least they got Bill McKibben to stop promoting biomass burning". WRONG!
Here's his review, with references going back to 2016, where he changed his mind way before the film was released.
end update April 28, 2020

While I'm glad to see that much attention is being paid to overpopulation and to consumption of things and energy. I'm also glad that wood chip biomass is getting the roasting it usually so richly deserves, and that the Sierra Club is being exposed too.
But, much of the rest of this documentary is frankly lies or misleading. It appears to be filmed back in 2011/2012, and so much in the world has changed since then, particularly in the world of renewables.

Detailed Review

I note the timestamps from the version on the site
Then I note "LIE" or "MISLEADING".

=== NOTE: incomplete but already hugely long ===

4:32 "Forget throwing plastic bottles in the water, we tossed our cars in there".
MISLEADING       Actually, the cars seen here are used, as many were elsewhere in those days, as revetment on the outside curve of this stream bend.

12:05 Chevy Volt - note this car was released in 2011.  (and production of it ended in 2019)

 NOTE  Much of this documentary seems to be stuck in 2011/2012, so their statistics are very, very outdated.

12:42 (GM person speaking) "Everybody thought we killed the electric vehicle. No we didn't.
        It's alive and well."
LIE (on GMs part)
        Chevy Volt production ended in 2019, why that is is unclear, the Volt was the world's all-time best selling plug-in hybrid (PHEV). While they have brought out the Bolt - a battery EV, many people were still interested in the PHEV.

14:36 Michigan's largest solar array.
MISLEADING In fact this is a tiny array (power-wise) as far as solar arrays go.
        It is made with amorphous silicon modules from the former Michigan company Uni-Solar
        (United Solar Ovonic, LLC), a subsidiary of Energy Conversion Devices. Due to the low efficiency
        of this technology, and the high expense of flexible modules, the company went bankrupt
        on Feb 14, 2012.
        The 8% quoted efficiency is low, Uni-Solar was typically quoting more like 11 or 12%.
        But that pales in comparison with the 18-20% efficient crystalline silicon modules currently readily available. Amorphous-silicon is now just a niche product for portable applications.
MISLEADING in fact a current technology array would be much smaller or provide for more homes. Either the documentary makers are clueless, or they are trying to make PV look bad. In either case, it discourages people from being interested in PV systems.

And it's tiny compared to this utility scale array from a couple years ago. 11,000 homes is a few more than 10 or 60. Things have changed a lot in just 8 years.

16:59 "Then the cell ..." (sic)
TYPO - the "nacelle" is what is mounted at the top of the tower with the actual generator inside and the hub and blades mounted on the upwind side. Should be "The nacelle is 220,000 pounds".

17:26 Vermont wind turbine site -

18:19 "And how long are these towers supposed to last?"
        20 years is derided as "a nano-second"
LIE - the project has a 25 year permit (see article below).
MISLEADING - while it may be that the original towers will be taken down in 25 years, it is essentially a sure bet that if allowed, the turbine owner will "re-power" the site with latest generation machines.  There is no reason that a good turbine site would not be used in perpetuity.
        This is totally unlike mountain top removal for coal, where the acid waste will pollute the valley below for hundreds or thousands of years in an (arguable unfair) exchange for a few years of coal.

        I'm also curious how those people got themselves and their synthetic material outdoor gear to the mountain.

DATED Here's a 2013 article about the project - after completion.  Why is the documentary so out of date?

        And we're not told who previously owned the land. Ah - this link below answers it: it was a working timber farm. The above article says 2800 acres of land is now preserved because of the project.
        You would think a documentary trashing woody biomass would take note of this.

18:50 man saying you've got to have power plants at idle AND they use the same energy as if they were running at full power.
LIE should be self explanatory.

19:41 "but we've got to deal with population growth"
        YES! One of my main beefs with the Sierra Club is they changed their tune about population when an investor bought them out of their sustainable immigration position.

19:48 "All this energy's supposedly going to heat a water park".
DUBIOUS - the project puts power out to the general grid, enough for 24,000 to 27,000 homes.
        Why the wacky conspiracy nut stuff? Name the water park or shut up.

19:57 "Green Mountain will be bought out by Gaz Metro, and Gaz Metro is owned by Enbridge ..."
HALF TRUTH - Gaz Metro already owned Green Mountain Power as of 2007. Gaz Metro is co-owned by Enbridge and The Caisse.  If this guy can't get some simple facts straight, why is he a trustworthy source?

20:54 Hydrogen Car exhibit
LIE  by GM Hydrogen huckster: "This is like a perpetual energy battery."

        My sympathy to Jeff here - anytime somebody says "perpetual", watch out.
The hydrogen hype machine just doesn't seem to quit.  One wonders why, it is easy to see that when we get to a sustainable situation (since Business-As-Usual is NOT sustainable), hydrogen from fossil fuels will be gone, so we are left with hydrogen from:
  *     water-gas shift reaction from woody biomass: oh yeah, biomass, not enough to use sustainably, never mind.
  *     fermentation: nice if it works, but doesn't exist in practice yet (if ever). And uh - what are we going to feed the "bugs" if biomass is insufficient? Oh, never mind again.
  *     electrolysis: not so efficient. Why not just charge a battery?

        That EVs are much more efficient than hydrogen fuel cell cars has been known rather decisively since 2006.
        The only advantage of a hydrogen car over an EV now is a more rapid refill time.
        But despite a comment on the above article from 2008 that BEVs cannot go 300 miles on a charge, many of the BEVs available in 2020 can do just that. And fast charging keeps getting faster.
        Do we have to rush through life as fast as possible? I think not.
        And, there's a small matter of exploding hydrogen infrastructure too:

21:15 Zoo eyes elephant poo as energy source
COMMENT: Jeff seems to deride something that helps as not worth doing if it doesn't totally cover everything, an all or nothing mentality. I think that sort of thinking is part of the problem.

NOTE: if the manure is just left to rot in a landfill, it will generate methane emissions. If digested in a biogas digester, then the methane burned, the effective greenhouse gas emission is less that letting the methane go wild. And one has some electricity and/or heat.

MISLEADING: When I tried to find an update to the story, all I found were the original flurry of poo stories from 2005, then nothing else about the Syracuse zoo and poo.
        Neither their website nor this 2015 article talks about power from poo.
        Jeff says "I read about a zoo that was said to be powered by elephant manure", but the NBC article just says they were "looking to be first" and "studying how feasible it would be".
        Is Jeff just really sloppy, or is he intentionally misleading us?

        But there _are_ zoos around the world who are powering parts of their operations with biogas digestors. Munich (note the 2011 date!), Tokyo, Toronto (in development) and Detroit

21:34 Ethanol plants

        The documentary wasted a good opportunity here to introduce and talk about the concept of Energy Return on Energy Investment (EROEI sometimes just written EROI).  It's the ratio of the energy one gets from a source to the sum of the energy involved in producing or extracting it.
        Everybody who is concerned about sustainability ought to be familiar with the concept, and with this paper from 2009: What is the Minimum EROI that a Sustainable Society Must Have?
        Obviously, if one gets less energy out that one puts in, the economics and sensibleness are questionable. Indeed Hall et. al. find in the above paper that a minimum EROEI for society to just function is about 3.
        For corn ethanol, the EROEI has always been at or near 1.
        This article on The Oil Drum from 2010 is a good summary.
        It should be obvious that the whole corn ethanol program is a farm subsidy program. So if this was well known in 2010, why is it such a huge surprise to an "environmentalist" in 2020?  The general population I can see, but someone who wrote for Mother Earth News?

        Without the basis of EROEI and other factual, numerical comparisons, how is the viewer to do any reasonable evaluation of the various renewables? Is Jeff somebody who doesn't do numbers and is thus handicapped in thinking about these issues?
        Or is this an attempt to smear all renewables with "just a scam"?

22:25 Richard Heinberg
        Heinberg published _Powerdown: Options and Actions for a Post Carbon World_ in 2004, with predictions of imminent peak oil. We peak oil watchers were all blindsided by fracing and oil sands.  Peak oil within a decade just didn't happen, though the global financial crisis of 2008 was a close brush with peak oil. In the more recent _Out Renewable Future_ from 2015, Heinberg seems to be saying renewables are do-able, but it won't be easy.
        Yet this clip has him saying "I'e counted like 25 alternative energy options. So surely, among all of those, there are enough sources of energy ... That's not the reality."
        Then Heinberg continues with a comment that in some cases we get no energy from them.
        Again, the documentary is dated, and important growth in renewables has occurred since the 2011-2012 timeframe of the filming, so I have to rate this as misleading as well.
There's no specification of what these sources are, just vague innuendo.

22:39 Richard York - the study in Nature
        The study was published March 18, 2012.

        It covered the period 1960-2009, a period where solar and wind grew from nothing to merely insignificant, but at least kind of countable.
        York's result was that each unit of renewable electricity only displaced less than 1/10th of a unit of fossil fuel electricity.
        But 2 years later, in a conference paper, Liddle and Sadorsky revisted the issue. They covered the period 1971-2010, and claim a more robust treatment of the data.
        See discussion at top of page 4 in
        They found that non-fossil fuel sources displace about 1/2 unit of fossil fuel generation,  significantly larger.

        But we have even more renewables now, and I think the issue is pretty well settled. At large enough renewables penetration, the grid operators are now savvy enough to deal with it.
        We see this from the UK now. With the covid-19 pandemic minimizing travel thus air pollution, and the approach of summer, the sky over the UK is clear and sunny. So much solar energy is being generated that all the coal plants have shut down.

24:19 Ozzie Zehner

24:33 "One of the most dangerous things right now is the illusion that alternative technologies like wind and solar, are somehow different than fossil fuels."
MISLEADING ALARMISM free fuel and intermittency, sounds pretty different to me.
        He whines that people say solar cells are made of sand, but he lets us in on this amazing secret - they're actually made of quartz.  Duh Ozzie, most sand is quartz, aka silicon dioxide, aka silica, SiO2. Beach sand may or may not be too dirty (note the "pure quartz" Ozzie has is slightly discolored with minerals), but it isn't used for another reason: the small grains will impede the flow of gas away from the reaction zone in the arc furnace.

        When you put the coal and wood shavings and crushed (not so pure) silica rock into the electric arc furnace, the impurities in the coal and wood alone means your metallurgical grade silicon is at most 99% pure.
        No need for the hyperpure quartz from Spruce Pine, North Carolina. The metallurgical grade silicon is purified by turning it into a volatile compound trichlorosilane (SiHCl3), which is then distilled to exquisite purity, as much as 99.9999999% pure. Then high purity polysilicon is deposited from the trichlorosilane onto seed rods in a Siemans reactor. (I'll ignore the fluidized bed process, since it has little market share).

        Where you do need the Spruce Pine ultra-pure quartz is when one melts the high purity polysilicon to form it into a single crystal round "boule" via the Czochralski method, or makes a flattened square multi-crystalline directionally solidified ingot.  The crucibles used are made from the hyperpure quartz so they don't contaminate the molten high purity silicon, and are only good for a single ingot or maybe a couple of boules.

25:18 "You can't use sand because sand has too many impurities."
LIE     As explained above, this isn't true. One actually avoids the use of sand because the small grains will impede the flow of gas away from the reaction zone.

        I'll let the comment about silicon metal and carbon dioxide go (it's silicon and carbon monoxide). The CO is finally turned into CO2 at the top of the furnace.

25:54 Jeff: "Ozzie Zehner said it was an illusion that renewables were replacing coal or any fossil fuel."
LIE     see above about the UK and solar output.

        Zehner continues his lies about solar not replacing coal by saying they're just replacing the coal plant with natural gas plants. First, these coal plants are often old and rundown - industrial equipment doesn't last forever, particularly those exposed to high temperatures and the corrosive coal exhaust gases. Second, many coal plants pollution control equipment doesn't meet new standards. Third, natural gas is cheaper than coal, both because of fracking leading to high availability, and because combined cycle plants are much more efficient. Fourth, the natural gas plants are more flexible, and better able to back up solar. But they don't run full out just spewing CO2 into the air during the day when solar is working, they're throttled down or even turned off.

26:57 Ozzie: (re Iowa) "But then they're building a larger natural gas plant." "This is a 650 megawatt natural gas plant. That's 4 times for megawatts that the coal plant over there that it's replacing".

LIE #1  It's 706 megawatts per Alliant's web site.
LIE #2  it actually replaces "14 less efficient, smaller older generating units". Yes, fourteen. So no wonder it's bigger than the one across the street.

        And another reason gas is shutting down coal - "... needs 90% less water supply than the units it replace."

        More good news from Alliant: "less than half the carbon dioxide, two-thirds less nitrogen oxides and roughly 99% less sulfur and mercury than traditional coal-fired generation."

        And explicitly: "The generating station also supports our growing investments in renewable energy. It has the ability to adjust its output up and down quickly. This provides flexibility to better integrate wind and solar power into the electric supply mix."

        More evidence that Ozzie is lying about wind not replacing fossil fuels.
        If you go to the Alliant Energy site link above, then click on "Our Energy Vision", you'll see down at the bottom of the pop right menu "Generation Projects". Half the links are wind, the other half are natural gas. Now look above under "Advancing Clean Energy" and explore. One will find a page about wind generation.

        One finds the utility saying: "Wind has no associated fuel expenses, which helps provide long-term cost stability to customers." If it wasn't economic, why would the utility build it?
        The only way it's economic is if it replaces fossil fuels - even cheap natural gas - enough to pay back the cost of building the wind turbines.

NOTE: fossil fuel plants also need backup, they are known to go down suddenly, so there must always exist sufficient backup online to deal with loss of the biggest plant on the transmission network.

=== that's it for now, barely 1/3 into this and the lies are rampant.

Friday, January 31, 2014

Review: Spain's Photovoltaic Revolution

Review of Spain's Photovoltaic Revolution - The Energy Return on Investment
Pedro S. Prieto, Charles A.S. Hall
Springer, 2013

No getting around it, I was disappointed.

First, I pay $47 bucks, and I get a 3/8" (1cm) thick x 6" x 9.25" paperback.
(was expecting something larger).

Well, OK, if it has real data, from a real owner of a real PV system, then maybe it's worth it.

Or maybe not.  Maybe part of my sense of disappointment is the let down in my expectations, I was looking for things I didn't know.  If you don't know anything about EROEI, a much better place is in Energy and the Wealth of Nations - Understanding the Biophysical Economy, Hall & Klitgaard, Springer 2012.

Disappointed to have dated information, the last info on world oil and gas production was 2010 in a book with a 2013 copyright. (pg. 2).

pg. 3 - "… where something is expensive in dollars, it will be expensive in energy".  This doesn't follow, look at any art auction, luxury autos, etc.  Or more to the point, home prices in the housing bubble that ended in 2008 with loss of monetary value, in some cases over 50%.  Did the embodied energy in those houses change when their price collapsed?  No.

Was disappointed to see Prieto and Hall ascribing the lack of monuments of hunter-gathers to low EROEI (n.b. they say EROI, which many find confusing: is it money or energy invested?).  Because hunter-gathers typically were transient, they didn't stay around long enough to do any building, nor why would they?  Without a king ruling over them to crack the whip, why would a small band even attempt a big pyramid?  People are lazy and social, way better to hang out with the tribe and talk story than haul big stones around.  Big irrigation and structural works have to wait until there's a king with a big enough population to boss them around.

They seem to buy into the notion of agriculture as the fruit of "progress", having either not read or not been impressed with the evidence that agriculture was not so much "invented" as was forced into practice by people under desperate conditions (climate,  Pleistocene Overkill, overpopulation).

(short book)
Neanderthals, Bandits and Farmers: How Agriculture Really Began - Colin Tudge
(long details)
The Food Crisis in Prehistory: Overpopulation and the Origins of Agriculture - Mark Nathan Cohen

They ascribe (from others) the EROEI of 10:1 for hunter-gatherers, but here we get into the hard problem with EROEI - how to draw the boundaries.  Most hunter-gatherers, under good conditions, only work a few hours a day.  Do we say the hour they work gives them 10 hours of free time?  Or do we say they feed themselves, a young child, and elder and a mate - thus EROEI 4:1 ?  This begs the question: what is the minimal EROEI of a society needs for maintenance or for growth?  While it is clear that hunter-gatherers typically had more energy available than they needed, an actual number for EROEI is now less clear after pondering this book.

I'm puzzled over the reference on pg. 15 to "Al Gore's Kyoto Protocol".  He advocated for it, but the protocol was the work of many, many others, and is done as a UN initiative.  Is there a sub-text of disparaging climate change mitigation and/or environmentalism/renewable energy?

One of the premises of the book is that Spain is a great place to study PV due to the good sun resource, and stable PV generation.  But this is un-clear, because of the way the Spanish government created the boom and bust of PV in Spain.

Chapter 3 is a decent history of that government incentive, and how the market exploded due to overly generous incentives.  One thing missing in this book though, is that Spain's retail electrical rates are (still) partly regulated, and were/are kept artificially low (can you say "bread and circuses"?). But with the oil and other energy price shocks, that government subsidy exploded.  Then with the financial crisis beginning in 2008, the Spanish government was overwhelmed with debt, and had to take action, meaning cut spending, so very few people in Spain are happy.  My point is that not just the PV land rush is to blame for the austerity crisis.

I think Prieto & Hall place a bit too much blame on industry, whereas I see industry just responding to rather goofy government regulations.  First, the feed in tariff offered was far too large, about 15% bigger than Germany's.  This attracted the fraudsters that Prieto & Hall rightly complain about, as well as the inexperienced, both resulting in higher costs.  Second, there was no reservation system to limit the systems to what the government had budgeted.  The 2010 goal was about 400 MW as I recall, but that level was already surpassed in 2007.  In 3/4 of the next year, while the Spanish government was figuring out what to do, another 2,700 MW of PV was installed.  In that respect, they wildly succeeded, over-achieving by nearly 10 times (not percent, times!).  But obviously the government blew their budget.

Third, the Spanish government arbitrarily set a limit of 100 kW per system (in an attempt to encourage small businesses), which businessmen merely circumvented by setting up little shell companies, one per 100 kW system.  This not only made the systems less efficient generators, it added to cost and presented opportunities for fraud.

The only new thing I learned is that due to the system limits and tariff structure, typical systems were overbuilt by 8%, which again increased costs - but those costs/inefficiencies were more than covered by the too-high subsidies.

Now the Spanish government is trying to stave off default, and to pay creditors of the historical electricity subsides as well as make payments on the current feed in tariffs.  The honest thing to do would be to raise electricity rates, but they're already high (Spain has no fossil fuels but a bit a lignite, and limited hydroelectricity), so that is politically unpalatable and would likely further depress the economy.

Which brings us back to the issue raised by Prieto & Hall, the EROEI of PV, which they claim is the major problem with the solar program.

I see several problems with their details, though compared to the wild days of EROEI 50+ imported oil, they are correct.  Society will be poorer, whether they like it or not.  The only question is how much poorer (and how soon).

(1) it's based on dated information, particularly systems costs.  I can see why, that they wanted to look at a couple of years of production from those systems, though it's still disappointing to see (only) old information used.
(2) the Spanish installations are typically overbuilt by 8%, which gives cost and some power, but much of this power is thrown away during peak sun times.  This is an artifact of government policy and not intrinsic to the technology.
(3) the calculation of energy investment based on total national energy use and GDP is rather loose.

They use 5.5 million Euro / MWp system cost, plus 30% O&M (operations and maintenance) over a 25 year plant life (pg. 44).  But those numbers are old.
In Tracking the Sun IV,
it says > 100 kWp systems are $1.9 in Germany pg. 20.
O&M costs don't scale down much, so I'll use 30% of the old 5.5 million Euro/MWp = 1.65 million Euro/MWp O&M. US$1.9 is now 1.41 Euro, round this up to 1.45 for a total lifetime system cost of 3.1 million Euro instead of 7.15 million Euro for the old numbers.  So the rough EROEI from page 44 goes from 2.41 to 5.56.
While this is not great news in an absolute sense, EROEI of 5.5 means essentially twice the civilization of 2.4.

When they did their "how much energy out" calc, they down-rated for 8% due to the Spanish overbuilding (pg 49).  Nobody else that I know of did that, and they're not doing it anymore in Spain, so this is somewhat dubious.  Tossing this means their "losses not generally accounted for" go down from 23.5% to 15.5%, and the rough EROEI with current costs goes to 6.15.

The rough calculations were done on the basis of the total economy of Spain and how much energy they use.  They take the energy used by Spain in 2008 in million tons of oil equivalent and divide by the GDP, and end up with 7.16 MJoule/Euro.

Now, is this really true?
Notice that with the updated costs, the EROEI more than doubled, but did the actual embedded energy go down by half?  Certainly it went down, people are getting smarted about racking for example, and don't use so much concrete these days, but did the actual energy invested halve?

Another example of the questionable nature of their money-to-energy assumption - PV system prices in the U.S. are higher, due to lack of scale, more paperwork, and more cost in customer acquisition.  If a U.S. PV system is twice the price of a German system, does it have twice the embedded energy?  Seems bizarre to assume so.  Two neighboring states, one taxes PV systems, the other doesn't, otherwise the system cost is the same.  Is the system in the taxing state have a worse EROEI?

It would have been interesting to compare other forms of energy generation using these metrics, but they are not in evidence.

They admit to the imprecision of the total energy/total GDP assumption, and in fact show that the true range for energy intensity per monetary unit vary widely.  In Table 4.1, they show the results of a study from Carnegie Mellon University that shows a range from 21.4 MJ/$ down to 1.54 MJ/$, with the US average of 9.68 MJ/$.  So where does PV fit in?

So they go through the parts and process of building of a PV plant in some detail in Chapter 6.  While it's a comprehensive list, my problem and disappointment is all the "we assume this, then double that".

I paid $47 for an EROEI analysis based on assumptions?  And then once they get their mostly economic assumptions made, they use some rough factor of the 7.16 MJ/Euro (half for this, twice for that) to get energy.   They end up with an EROEI of 2.45 with their detailed calculations, which corrected for current system prices goes to 5.65.  They provide a sensitivity analysis case that corrects for the Spanish aberrations, resulting in 2.84, with current prices that's 6.55.

There's a bit of an unfortunate gulf between the Energy Payback Time and LifeCycle Analysis studies of modules, which show current EPBTs under a year for modules, but are based on exact measurements of the energy used per machine, per factory, etc., and the final system EPBT.  But there are a few recent studies out there that show whole systems, with increasing detail.

slide show from Fraunhofer refers to 1.5 years EPBT for systems.  Even if one doubled that to include O&M, one gets an EROEI of 8 over 25 years.
See slide 32 more more info:

A short article of EPBT:

A major nit - page 80 talks of ingots and cells mostly  "… imported from the world microchip technology sector …"  Microchips and silicon PV have about one commonality, they start from polysilicon.  Otherwise they're different industries, and the PV industry, even in 2007, used several times more polysilicon than the chip industry (thus the insane poly prices in those years).

So, I'm disappointed.  I was looking for hard numbers, and I got a ".. we are left with a somewhat ambiguous picture of solar energy in Spain."

They do raise a lot of good questions though, and I agree with their call that we need to do a lot of work on EROEI - for all energy sources.

As for the book, unless you're a complete EROEI geek and won't miss $47 at all, I can't really recommend it.

original 20140131
edit 20140131 US PV system costs vs. EROEI

Saturday, January 11, 2014

Some comments on Sustainable Energy - Without the Hot Air

Some comments on Sustainable Energy - Without the Hot Air
an online and printed book by David JC MacKay
free online at:

per request from Ruben commenting at

my original reply at:

Below I've expanded a tiny bit, but generally a cut and paste of a reply to "Will" claiming that Without the Hot Air finds non-fossil energy sources "adequate".

Sustainable Energy - Without the Hot Air is well written and informative, and I recommend it to all interested in sustainability.  Especially since the online version is free, one has very little excuse not to read it.  The premise of MacKay's work - that we must get sustainable, and must be realistic about it - is a breath of fresh air in the storm of metaphorical "hot air" that surrounds the issue of sustainability.

Even though it is written specifically for the UK, one can generalize the process as MacKay goes through the alternatives in enough detail to convey the magnitude of the problems and needed scale of the solutions.  One finds cause for both alarm and some optimism.  However, non-technical issues of politics and economics are not covered in detail, because those are out of his control and expertise.  The gist one can takes home from this is: there is a lot that humanity technically could do to become sustainable, though it would be economically costly and require lifestyle changes, but the even bigger question is will humanity choose to do them?

Adding up current energy consumption and the technical possibilities for sustainable energy sources shows that the UK can almost meet current energy with non-fossil fuel sources.

But as MacKay explains here:
" … in calculating our production stack we threw all economic, social and environmental constraints to the wind."

(and note the production stack shown is slightly smaller than the current consumption stack, indicating that some lifestyle changes are inevitable.)

The rest of that chapter he looks at other estimates, and at the politics - and things don't look so rosy. Yes, PV can power the world, if we all had the willpower to accept peak oil… and that we ought to and can do something, and decided to make the massive investments and changes in lifestyle needed. But most people are like Tony Blair - one moment claiming the utmost urgency, but then when asked about not flying to the Barbados for holiday, he dismissed that idea as "a bit impractical actually".

Thoughout the book, MacKay keeps telling us he doesn't care which alternatives we choose, just that we must be honest and that the chosen alternatives "must add up!"

My only quibble is that, for nuclear power, MacKay was (in 2009) still buying the line that a Gigawatt coal or nuclear plant cost a billion pounds (roughly a billion Euro, or 1 Euro/watt).

Unfortunately, the current nuclear industry, among several incompetencies it has shown, has not been good at cost-effectiveness, and regardless of one's technological leanings pro or con, is becoming irrelevant from a cost perspective.
The EPR (European Pressurized Reactor) going up in Finland, 1600 MWe, was initially 3.7 Billion Euro, but as of 2012, costs are now estimated at 8 Billion Euro.

8 Billion Euro / 1.6 GWe = 5 Euro/We.
In Germany that could build 2+ GWp of photovoltaics (PV), with no fuel costs, and no radioactive waste disposal issue. If PV module costs come down to 50 cents/Wp, and balance-of-systems (BOS) went that low, 20% capacity factor PV would be way way cheaper than "advanced" nukes.

Here's a nice brochure from E.ON on why they decommissioned the Stade nuclear power plant - it was no longer economical.  This was back in 2003, before anyone heard of Fukushima (March 2011).

So, even though MacKay's book is a tiny bit dated, it's still well worth a look, if you want a nice dose of reality.

Not really germane, but I'll leave this in and expand some, since energy storage is quite useful for many renewables to cover the intermittency of PV and wind for example.

Will gave a link to:
That in turn refers to the abstract in Nature

In typical sensationalistic press, a bit of rhubarb can save us all.
But as reading MacKay should warn us - we need to make sure this will really add up.

The use of electrochemically active organic compounds would be nice in that they are not limited by rare elements.  The 9,10-anthraquinone-2,7-disulphonic acid used by the group at Harvard, as well as the bromine "redox" (reduction/oxidation) couple (e.g. able to take up and give off electrons), are not rare.  Carbon, hydrogen, oxygen, sulfur and bromine are fairly common.

While the base compound, 9,10-anthraquinone, can be found in many plants, hence the rhubarb picture in the press, one must be careful of claims that bio-based solutions will actually work.  (c.f. corn ethanol and it's EROEI).

A quick web search "anthaquinone content of rhubarb" found this:
The focus of this work is the total anthaquinones content in the rhubarb for Oriental medicine, noting that the Chinese Pharmacopoeia specifies not less that 1.5% total anthaquinones.  First one wonders how easy it is to convert these various anthaquinones to the desired one.  Then one learns there is great variability in content, depending of species and more critically, elevation. At the highest elevations, like the Tibetan plateau, plants contain more, up to 6%, because they increase the glucose, etc. content of their sap to survive cold temperatures, and the glucose binds with the anthaquinones which then bioaccumulate.  My take is that rather than fight the Chinese for a limited supply of Tibetan rhubarb to make flow batteries, we'd just synthesis the pure stuff from anthracene (coal tar) or from benzene and phthalic anhydride.  So - the "adding up" of this looks a bit questionable.

Flow batteries are nice for large scale storage, since the amount of electricity one stores is determined by the quantity of the liquid electrolytes one has, and storage tanks are typically much cheaper than battery electrodes.

This anthraquinone based flow battery is interesting (due to the non-rarity and cheapness of the chemicals - at least until coal runs out) , though it requires a proton exchange membrane (if I interpret the fuzzy graphic right). Probably not great energy density due to the molecular size. Definitely be checking my mailbox for this issue of Nature in a few days.

Some guys at Stanford have recently developed a membrane-less Lithium Polysulfide flow battery.

I would suppose this would be much more energy dense (fewer atoms per stored electron), as well as avoiding the issues of a membrane that tends to foul over time.  

Friday, November 1, 2013

Krampus Wish List - Simple Electronics

This is part 3 of a series in response to

I cover the simple electronic devices that could be made, subject to certain assumptions, in a "post-industrial" world where fossil fuels are depleted and humans must live sustainably.  In part 1 I have covered the production of silicon wafers, the starting point for a photovoltaics (PV) technology (further described in part 2) and for simple electronics devices, as described herein.


Life today seems impossible without computers and smart phones, yet these are recent developments that depend on complex and expensive supply chains and support systems, that in turn depend on economies of scale, in turn depending on (cheap) fossil fuels to support a growth-oriented prosperity.  It's impossible to predict where things will end up in the economic trade-offs, but without the money push to buy the latest new features, some small number of semiconductor fabs could supply the world's needs, if the money is there to support them.  But without growth and cheap energy (e.g. fossil fuels), money will be in short supply, so things will get simplified.

But how simple?  A basic transistor or two enables radio receivers, which are quite valuable
for news, weather, farm prices, entertainment, etc.  A few more can make a simple transceiver (think CB radio), adding two way communication, meaning aid can be summoned faster, trades can be discussed faster/easier - especially in light of the reduced mobility likely in a fossil fuel free world.

A few power transistors and some simple ICs make an efficient, reliable, life conserving charging/management system for storage batteries, which extends the utility of small wind turbines, PV systems, solar thermal electric, wood burning Stirling engines, and the like.

A few more and bigger power semiconductors, and one can build inverters, and run AC motors, which means longer life/higher reliability due to the replacement of commutators and the attendant brush wear with slip rings, or with permanent magnet motors, not even any slip rings (by electrically commutating the stationary windings on the outside of the motor).  On a per-motor basis, like an electric buggy/bike/train/..., one can do efficient speed control and regenerative braking.

Simple, reliable motors mean more effective things like refrigeration, circulation pumps for solar hot water and ground source heat pumps, water pumps for irrigation, fans for ventilation, and I'm sure many more applications.  In conjunction with some simple electronics, motors can be used to track the sun for solar collectors, which means higher temperatures for solar thermal systems and more output per day for all solar collectors.

Another source of motivation is that semiconductors do have "wear-out" mechanisms, depending on how they're used.  Contaminants eventually leak into packages, causing corrosion and shifts in electronic properties.  Electromigration due to the flow of electrons displacing the atoms in conductors causes open circuits, and electrostatic displacement of atoms can cause short circuits.  Diffusion of dopants and contaminating impurities within the solid semiconductor crystal will in time alter the device characteristics, resulting in malfunction.  While commercial semiconductors can be made to work reliably for some 10s of years, say 20 or 30, when we get into the 100 year or longer timeframe, failures will be quite high. [4]  Also note that the "passive" components used in electronics systems, like resistors and capacitors, also have failure mechanisms.  Thus unless we replace broken devices, it won't be long until we won't have anymore.

The Evolution Of The Semiconductor Industry

The solid state transistor was invented in 1947 [1], it was a very crude device, requiring no special environment to make.  Since it was fragile, other kinds of transistors were developed through the 1940's and 1950's.  But these were still made in ordinary environments without that much work at extraordinary cleanliness. Transistors were initially made individually, mostly by hand.  Around 1958/59, with the application of photolithography techniques from the printing industry, together with diffusion doping, multiple transistors started being made on a single wafer, which was then cut into separate "die", each with one transistor on it.  Shortly thereafter, multiple transistors were made and hooked together on a single die and the integrated circuit (IC) was born. [2]

The very first ICs had fairly crude dimensions, lines on the order of 100th of an inch (.25 mm), easily achievable with photolithography, and not too susceptible to things like dust particles, though hairs and lint could be problematic.  So the first "clean rooms" started to be in use for electronics.  Clean room techniques were developed a bit earlier, especially during World War II to deal with miniature ball bearings and other tiny components. [3]

Air conditioning is a must for clean rooms, both to circulate air through fine filters and to maintain a reasonable temperature, since any heat inside the room must be removed artificially because letting in fresh air will just dirty the place.  And in most clean room applications, air conditioning is required to maintain a constant temperature due to the small tolerances of the items being made, which would be overwhelmed by thermal expansion/contraction.  Without temperature control, items made early one day would not fit items made in the hot afternoon.  Even a single wafer being processed must match a series of masks, which would be different relative sizes at different temperatures.

Cleanrooms come in different "classes" according to the need.  The latest microprocessors require class 1 (ISO 3) or better cleanrooms. [5]  Class 1 means no more than 1 particle measuring bigger than .5 um in each cubic foot of air (35 per cubic meter).  This is an enormous undertaking.  The cleanroom must be positively pressurized, to keep any dirt out.  The air blows down from the ceiling and out through the floor to sweep particles away.  Very fine filters, with large pressure losses, filter all the air many times an hour.  Redundant filter setups are required to allow changing filters without losing cleanliness.  Everything that goes into the cleanroom must be thoroughly cleaned.  We've probably all seen some picture of the "bunny suits" warn by technicians in modern fabs.  These must be made of synthetic fabrics that won't shed any lint.  Along with hoods and booties, they too much be cleaned before use and maintained.  Some fabs require fully contained suits, filtering the wearer's breath.  To help keep contaminants off wafers, they are now transported from machine to machine inside Front Opening Unified Pods (FOUPs).  All these things are made of plastics, meaning petroleum.  And many are disposable, especially the cleaning wipes and sooner or later the suits.

In contrast, PV fabs barely have cleanrooms - class 100,000 (ISO 8), the lowest cleanroom class - to keep metallic dust down that would cut a percent or two off the efficiency of the cells.  Basically some better than normal air filters and paying attention to ductwork for a regular air-conditioning system.

A property of ICs is that by shrinking the transistors and interconnections, one can trade off putting more on a single chip (increased function) or making more chips per wafer (decreased cost per function).  Since integrated circuits have to be designed into a system, IC manufacturers want to be at the leading edge of features, so they can have more "design wins" than their competitors.  While this is costly up front, as a generation of ICs is produced, experience is gained, yield goes up, cost goes down, and profits go up, especially at high sales volumes.  So there is great pressure to shrink feature size.  In 1971, Intel came out with their first microprocessor, the 4004.  It had 10 um features and 2,300 transistors.  A sheet of 20 pound typing paper is about 100 um thick.  Blue light, used in the photolithographic process, has a wavelength a little less than .5 um, so 10 um features are easy to see under visible light, and easy to use conventional photolithographic "masks" (like a photographic negative) to expose the patterns needed.  By 2000, the Pentium 4 had 0.18 um features and 4.2 million transistors, and in 2012 the 3rd generation Core processor has 0.022 um (22 nm) features and 1.4 billion transistors.  The diameter of a single atom is around 0.1 nm, so chip features are now just a few 100 atoms big. [6]

Photolithography of semiconductors started simple.  A wafer was chucked onto a spin-able plate, then drops of a solution of photoresist were dropped onto the center.  As the wafer is spun, this will spread out into a uniform thin layer and harden as the solvent evaporates.  After letting the resist dry, a full wafer mask would be aligned and set face down on the wafer and exposed to blue or UV light.  Then the resist is chemically developed, leaving some on the wafer and other areas where it was removed.  Now the wafer could be exposed to etchants that  remove unwanted areas, or to additive processes to create structures only where wanted.  Soon masks became so complex, and tolerances so fine, that a mask for the whole wafer was no longer economical or gave good yield if actually pressed onto the wafer.  So "step and repeat" machines were developed that exposed each chip's area individually by projecting light through the mask.  This also relaxed mask constraints so the masks could be made larger than the resultant feature size. [7]  These days features are much smaller than visible light, so ultraviolet light from excimer lasers is used, as well as tricks like phase-contrast masks to get sub-wavelength resolution.  These steppers are very complex and very expensive, $40 million each, and a large fab will have a dozen or so. [9]  Even the excimer lasers aren't fine enough for smaller features, so extreme ultraviolet lithography is being developed. [8]

While the costs per wafer are going up, the costs per transistor have been going down way faster, but it takes a large amount of capital to build and equip these plants.  PV wafer processing cost about $1, while a 300 mm wafer might cost $3,000 - $10,000. [10]  Even accounting the difference in wafer area, $3 to $3,000 means there's a lot more complexity on a semiconductor wafer.  A simple recipe for an IC has more than 20 steps, here's one from a university [11].  It lists most of the supplies, chemicals and equipment needed, including the 4 masks.  The early masks were "taped out" by hand [13] and photographically reduced with ordinary high resolution film.  Now, a complex process for state of the art microprocessors will have more than 300 steps, and a set of 30 or so masks. [12]  The features on masks are now so small that electron beams are used to "write" them.  The finer features/small light wavelengths require new photoresists, which require new solvents to apply them and new solvents to dissolve them.  Other layers may be required/desired below or above the actual photoresist layer. [15]  All these chemicals keep getting more and more complex.

Doping got more complex.  It started out as simple diffusion from gaseous, solid, or spun on precursors.  These days, ion implant machines, basically particle accelerators, blast dopant ions into the wafer.

As feature sizes decreased, simple wet etching needed to be replaced with dry plasma etching processes to avoid problems with microscopic gas bubbles blocking etchant action and to achieve the higher feature vertical aspect ratios desired.

Metallization to interconnect transistors has gotten vastly more complex.  The early metallization was just aluminum, evaporated or sputtered over patterned photoresist.  When the photoresist was washed off in solvent, aluminum was left behind on the bare silicon or oxide surface.  But when chip features got very small, two issues emerge.  Since aluminum is a light element, when conductors get small, it is subject to electromigration of the aluminum atoms from the pressure of the flowing electrons, resulting in open circuits.  The solution was to replace aluminum with copper, but that requires more steps, since putting copper directly on silicon will "poison" the devices, and copper can't be dry etched and is hard to evaporate or sputter, so it must be electroplated.  Since it can't be dry etched and wet etching is no longer fine enough, it must be over-deposited in trenches in the insulator around it, then chemical-mechanical planarization (CMP) to pattern, which requires more steps, and more chemicals/materials.  [14]

The current microprocessor/memory technology has become very complex, expensive and depends on complex supply chains.  While certainly important to the military industrial complex, the large market for consumer goods might shrink considerably in a declining economy.  And since the military depends to a large degree on Commercial Off The Shelf (COTS) items now, we all may be blindsided by a collapse of the IC industry or large parts of it.  Also, with a more fragile economy, recovery from things like the Fukushima earthquake may be more difficult/impossible - it had a significant effect on the IC industry. [16]

Processes for Simple Semiconductors

I will lay out some processing steps for simple semiconductors, using something like 10 - 20 um features ("rules"), which should be sufficient to make transistors and simple ICs like voltage regulators, op amps, and the like.

The first thing different from the silicon PV processing described in part 2 are more exacting cleaning requirements.  A simple dip in hydrofluoric acid (HF) will not do, since transistors are much more sensitive to contamination.  The standard IC clean starts with acetone, then isopropyl alcohol (IPA) , then a deionized/distilled (DI) water rinse.  Sources of these have already been covered, but the purity levels would need to be stepped up a notch, including freedom from particulates.  Natural fiber filters would work on these, but other things would require plastics.  A brief dip in dilute HF is to take off the native oxide that will form on silicon exposed to air. The next step depends on a hydrogen peroxide/ammonium hydroxide mixture.  Hydrogen peroxide has many pathways to make, and hopefully there is a large amount being made for paper bleaching, if not, the barium peroxide + acid method should be easy at small scale and the byproduct recyclable.  Ammonium hydroxide is just ammonia gas bubbled through water.  After that, comes another dip in HF to strip the oxide formed.  The next solution is hydrogen peroxide/sulfuric acid.  A fair amount of DI water rinsing is required, so some attention to water treatment/reuse will be required.  Also, personnel protection is an issue, so a supply of rubber gloves and aprons is needed.

Among the attributes of silicon that make it the semiconductor of choice is its stable, insoluble oxide.  So the first real processing step is to grow an oxide.  Oxides serve as masks for doping/implantation, insulating/passivation layers, and gate oxides for simple MOS transistors.  One needs a furnace that goes to 1100 deg. C (2000 F) or more, with a sealed chamber - typically a fused quartz tube.  Fused quartz rods are also used to build the "boats" that hold the wafers in the furnace.  A supply of oxygen, hydrogen and nitrogen gas is needed.  The nitrogen keeps a flow of gas always going out of the furnace, to try and keep contaminates out.  The oxygen and hydrogen are used in oxidation, the oxygen by itself makes oxide with different qualities than oxygen and hydrogen together, which make high temperature steam - a "wet" oxidation.  Often these are mixed in the same run.  Depending on the thickness of oxide layer desired, oxidation may take half an hour to several hours.

Once an oxide for masking is grown, photoresist must be laid down.  The wafer must be completely dry, so a minute on a warm hotplate is often used if it has been sitting around adsorbing water from the air.  Often a surfactant/bonding agent is used between the silicon and photoresist, often hexamethyldisilazane.  I would hope to skip this step for simple things, it's a kinda nasty chemical, but if we prepare silicones for PV encapsulation, it can easily be made.  A wafer is chucked on a spinner.  These have a vacuum chuck to hold the wafer down, and a motor and often a timer to quickly spin a wafer to several thousand rpm.  Then we drop on some liquid photoresist and spin it off.

There are two kinds of photoresists, positive tone and negative tone.  The positive resists dissolve where the light hit them, and the negative resists dissolve where the light did NOT hit them.  There are many kinds out there, so I'm reasonably sure something could be found.  There are all kinds of tradeoffs in choosing a resist.  Fortunately not much of it is needed.

Masked exposure is next.  Contact masks, where the mask is actually touching the resist on the wafer, are simplest, but have obvious wear and contamination problems.  Masks are made from glass or fuzed silica with a corrosion resistant metal on them, often chromium.  They are patterned photolithographically themselves, usually with a reduction lens from a larger pattern (at least for something like 10-20 um rules).  The light could be a mercury vapor light, or with the right resist, the sun.  Simple steppers could be used if the tradeoff from making many contact masks vs. the stepper works on in favor of it.

Resist development follows, where the dissolvable parts of the resist are washed away.  Some developers are as simple as a mild solution of sodium hydroxide, others are very complex.

After development, one typically needs to hardbake the resist to help it stand up to the following processing steps.  This is often done on a hotplate or small oven.

An alternative method of patterning might be nano-imprint lithography (NIL), though not at the nanometer scale.  Instead of photoresist, a warm, flowable polymer (or a UV curable liquid) is squeezed between a mold and the wafer surface.  When cooled (or cured), the mold is removed.  The polymer could be something as simple as beeswax.

Now one does an oxide etch, using HF and often an ammonia salt of HF, ammonium fluoride, easily made from HF and ammonium hydroxide.  This will etch holes in the oxide down to the silicon surface wherever the resist is not covering the oxide.

Often, the photoresist is removed before the next step, particularly if a high temperature step like diffusion follows.  This can be done with solvents, like acetone.  Now we have a waste, but we can distill that to recycle the acetone.  The other way is "ashing" - using an oxygen plasma to burn the photoresist. [17]  Typical RF requirements are 50 W at 30 kHz, well within simple vacuum tube or transistor capabilities.

Dopant deposition is the next step.  There are several alternatives.

Solid source doping uses wafers made of dopant precursors or have dopant precursors deposited on them.  They are place face to face with the masked wafer and heated so that dopant atoms diffuse to the masked wafer. The advantages are the usually non-toxic nature of the source.  It requires a hot furnace step, then cooling before the drive in step, so it is slow.  It's also not so controllable, due to the depletion of the dopant source wafers.

Gas source doping uses a gas (or volatilized liquid) in a hot furnace.  The dopant decomposes on the hot wafers.  It requires fairly sophisticated flow controllers to be repeatable.  It allows twice the wafers in a furnace as solid source doping, and one can often just shut off the dopant gas and then raise the furnace to 1100 - 1200 deg. C to do the drive in step.

Spin on sources are just liquids that are spun onto the wafer like photoresist, then baked in a hot furnace.  Typically it must cool and the "spin on glass" removed with HF, then back into a diffusion furnace, adding extra steps.

Drive in occurs when the wafers are heated to 1100 or 1200 deg. C, and the dopant atoms rapidly diffuse inward.  There are usually several dopings, so the "thermal budget" must be planned out in advance to avoid over diffusion of the first doping.  Often the masking oxide is removed just before this step, and another fresh oxide layer grown at the same time, in preparation for the next step.

An alternative is ion implantation.  If you'd ask me a few years ago about low tech semiconductor fabrication and ion implantation, I'd have laughed.  But there are some low cost implanters that have come out for PV, so I no longer think it that wild.  The PV style implanters don't mass analyze the ions, nor do they raster the beam, so they'd only work for unsophisticated electronics on small wafers - just like I'm thinking of here.  An advantage is that if the resist layer is thick enough, no oxide is needed to mask the implant.  One can use a rapid thermal process to anneal and activate the implant instead of an hour(s) long diffusion.  It would save creating and removing the oxide, and be better controlled than other doping methods.  Basically an ion implanter is a high current particle accelerator, like the Cockcroft-Walton invented in 1932, although the 50 - 100 keV needed is well within the range of a transformer and rectifier.

Once the drive-in step is done, if one has used an oxide mask and it is still there, one must remove it in HF, unless one is keeping it as the final oxide protective layer.

There are typically 2 or 3 diffusions/implants depending on what one is doing.  Simple transistors only take 2.  ICs will take sometimes take 3, as will thyristors and similar devices.

If doing metal oxide semiconductors (MOS), a gate insulator is needed.  For simple devices just grown an oxide layer, then do photoresist, a photomask, develop, hard bake, etch the oxide in HF, the remove the resist.  Gate oxides need to be of high quality, so they are typically grown "dry" with just oxygen, but that is much slower than "wet" oxidation.  Many process flows will leave the last "wet" oxide on the surface as a protective layer, etch down to bare silicon for the gate, then grow the gate oxide in those holes.

Next we need to etch off any oxide where we will put down metal.  Typical step as usual: spin on photoresist, expose photomask, develop, hard bake, etch oxide in HF, remove the resist.

Metallization is most simply done with evaporated aluminum.  Aluminum is compatible with silicon, and for crude devices like we're making with 10 or 20 um rules it's reliable.  It also works well with a process called "lift-off", where a layer of photoresist is laid down and patterned, leaving resist where we do NOT want the aluminum to end up.  Then we evaporate a layer of aluminum, then dissolve the resist and any aluminum on top of resist will come off too.  We could do a masked etch of the metal instead of lift-off, but now we need a metal etchant in our toolbox, which already has acetone in it, a good solvent for lift-off.

The evaporation machine is a sealed vessel, pumped down to a decent vacuum.  The simplest ones are just a tungsten filament on which little aluminum wires will be hung.  After a good vacuum is achieved, the filament is energized a bit and the aluminum wires melt and form balls by capillary action.  Then the filament is heated more, and the aluminum evaporates at 2519 deg. C., far below the melting point of tungsten at 3422 C.  Fancier evaporators use a ceramic crucible or electron beam to melt/vaporize aluminum. We'll put down about a um thick of aluminum of small signal devices, more on big power devices.

If we had a sputtering machine, we could use that instead of evaporation.

Lift-off requires using a solvent, like acetone, to reach in through the stepped edge of the aluminum layer.  Ashing will not work at this step.

The final step when doing aluminum contacts is to anneal the contacts, at 475 deg. C. in an inert or slightly reducing atmosphere.  This improves the electrical conductivity of the contact.

Now we test each device.  A prober will have a set of needles that can be lowered to contact each of the device input/output pads, and an electronic circuit to test the function.  This could be very simple - an function generator for input, and oscilloscope for output, and a picture of what's good or not.  The operator will mark bad die so we don't waste resources packaging them.  The prober will then be retracted and positioned over the next die.

The wafer is then diced.  These days most of sliced up with a dicing saw, which uses small diamond coated wheels.  With the right orientation of wafer, we can scribe with a diamond or tungsten carbide tipped scribe, and break the wafer into lines, and each line into die.

Then the die will be packaged.  These days most die are packaged in plastic, but I'm doubtful about that in a future petroleum short world.  The technology in the resins is actually pretty fancy.  Instead, we use plain old-fashioned metal or ceramic packages.  For small transistors, like the TO-18 for small ones, and TO-3 for large ones.  ICs with up to 8 or 10 leads can use the similar TO-99 package.  These are made of metal, with leads going into the base through hermetic metal-glass seals.  The die is attached to the base of the package, sometimes on an insulator, with a low temp eutectic solder or glass frit.  Then wires are run from the die to the metal leads.   The simplest way involves tiny gold wires.  These are obviously expensive, but easy since the gold is so soft.  A thin gold wire is fed through a tiny metal pipe like a hypodermic needle (with a flat, smoothed end).   A bit of wire is fed out through the tube and balled.  Formerly a tiny oxy-hydrogen flame was used, but these days an electrical discharge melts the tip of the gold wire, forming a ball.  Then the ball is pressed onto the IC pad and pressure welds to it.  The wire is draw over to the package lead, and smashed into that, bonding and pulling the wire apart. [18]  Copper and aluminum are also used for IC wire bonding, but have to be ultrasonically welded. [19]  After die bonding, it is common to test again, to make sure the attachments are good.  Then the cap is put on and sealed with a low temperature solder.


If you've made it this far, congratulations.  The manufacture of even simple transistors is non-trivial.  But nothing was extremely hard, or depended on sophisticated tools/controllers/exotic materials/complex infrastructure like modern microprocessors do.  A simple class 100,000 or 10,000 cleanroom should work well enough for transistors and simple ICs that would serve as simple radio amps, battery charge controllers and the like.

No sane military commander would go off to battle without two way radio if he could help it, and although tubes are much more low tech, their power requirements are much greater and that is problematic for mobile applications.  Radar and night vision equipment is also of great benefit for military use.

Having a good battery charge controller would greatly extend the life of storage batteries, and with small wind and/or solar being the only two near-universally applicable sustainable electricity generation means, there would be great economic benefit in that.

LEDs cannot be made from silicon, but the development of skills and infrastructure would greatly facilitate the practice of that technology, which uses similar equipment.  They would reduce power requirements for lighting by 80% over incandescent bulbs, and save even more money/effort/resources due to their long lifetime.

No promises can be made, but simple semiconductors don't look impossible, even in a somewhat resource constrained world.

============== References =============








And notice the power consumption for this fab - 55 MW going to 65 MW.




Note 3rd and 4th pictures.