2010: I finished HS and my 1st college term
2019: Fresh PhD, 4 mo. into my new role at @TheBTI.
Underlines for me that 2020s decarbonization + climate science work will be driven by people either *already* in field or *maybe* a lucky few who enter it in next ~5 yrs. (1/2)
Our bold climate youth are an inspiration, but they can only do so much. Virtually all of the heavy lifting on climate this decade will be done by those already of age today. Don't burden the next gen with your hope for climate progress in 2020s - that's largely up to us. (2/2)
(All my fierce student activism aside, I felt relegated to the sidelines for the '10s. Youths today can likely relate strongly. We'll see what my impact is in the '20s, but we must work hard on behalf of youths left desperately trying to contribute via mvmts like #ClimateStrike)
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From 2018 to 2023, silver use in solar PV cells has dropped by around half! (h/t @solar_chase)
Indeed academic papers (incl my own) tend to lean several yrs out of date. But industry intel is often paywalled, hence my habit of obnoxiously saving whatever nuggets I come across.
This is a clear example of why getting the stamp of peer-review doesn't mean something is right or the golden truth of science.
The most crucial round of peer review is really the permanent, continuous reactions/feedback from other experts once a study is actually publicly read.
I had assumed 10g per watt in my @Joule_CP paper, and had thought afterwards that might've been generous--but now it's right on the money.
Where I was way off was concrete, which is no longer used to anchor solar mountings in most utility-scale plants.
Finally found time yesterday evening to take an unofficial satellite's-eye-view tour of the quasi-legendary Spruce Pine ultra-high-purity quartz mine in North Carolina.
It'd be an understatement to say this mine is currently key to the semiconductor + solar PV industries. 🧵
IIRC, there's no other ultra-high-purity quartz mine of this scale, creating quite the potential bottleneck. A fire at a Spruce Pine facility may have contributed to the 2008 spike in polysilicon prices that arguably set off the last decade's solar boom.
Ultra-high-purity quartz is used for chip factory tools + crucibles used to contain molten silicon during manufacturing of ultrapure monocrystalline silicon ingots for chips + solar PV wafers via the Czochralski process. Pure quartz reduces impurities in the resulting product.
A flashy review paper from @ChristianOnRE + coauthors allegedly compiling hundreds of “100% renewable energy system” studies worldwide has received a lot of recent attention.
But this isn’t as big/rigorous of a field as such stated numbers might imply.
Untangling @enricomariutti's solar PV CO2 analysis as quoted by Shellenberger, Part 2
To his great credit, Enrico has made his calculations available, emphasizing he has nothing to hide.
In the same spirit I agreed to take a close look--and I think I've isolated the key issues.
I’m going to work through these numbers step by step below.
I’ve made a copy of Enrico’s calculations sheet that I’ll share here in case anybody else wants to take a look. Fair warning, the units change often and are not clearly denoted:
Enrico uses the full equivalent hours method here, assuming generation at full capacity for the equivalent of 1137 hours/yr in Italy. Other key factors include 25 year lifetime, module degradation at 2% the 1st year + 0.5%/yr thereafter, and 5.6% grid losses
I think this solar PV CO2 analysis from @enricomariutti promoted by Shellenberger is too high for reasons I'll point out.
Mariutti gives range of 170-250 g/kWh (!!)
Many literature estimates range 12-80 g/kWh
My rough estimate of upper-end is maybe a bit more than 72 g/kWh
I can appreciate why he likes the transparency of the 2006 study? But this misses the past 17 years of learning-by-doing as the solar-grade polysilicon sector has scaled many times over.
He takes 1.61 GWh/MWp as the electricity input for solar-grade polysilicon, for instance.
I struggle to think of sectors/technologies where the US truly has a vacuum of essential know-how. Even in areas like upstream silicon-based solar factories or LFP batteries where the US is behind, we're competitive in alternative commercial tech (CtTe solar + NMC batteries)...
I do think @robinsonmeyer is correct in pointing out Ford/CATL's proposed Michigan LFP battery factory as a case where Congressional anti-China posturing has impeded a project arguably in the US's net interest.
But it's incorrect that the US can't make LFP batteries otherwise.