In case anyone was wondering, I was rejected from the #NSFGRFP both rounds I applied.
I remember that the reviewer feedback felt very personal at the time. Lots of folks will suggest using the notes as a learning experience right away, but I'd actually suggest otherwise. (1/3)
Right now prob isn't the best time to try and take in reviewer comments. After your initial debrief w mentors, set the feedback aside for as long as you need to process the disappointment - even couple months or more. By then, you'll be separated enough from the experience (2/3)
for retrospection to be more valuable.
Try not to feel discouraged, and DO NOT compare yourself with your fellow grad students.
Rather, think back to your very first day on campus and reflect on *how much* you've grown - the answer is a helluva lot. Good job! Keep it up! END
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To supply low-carbon power to a grid via nuclear, solar, wind, or grid batteries, how much material must we dig up to build those power plants?
Answer: far less than for fossil fuels, with nuclear needing the least mining. New @TheBTI report by my team: thebreakthrough.org/issues/energy/…
Big takeaways:
Coal? Digs ~1.18 million kgs of rock+coal per GWh for fuel only
Solar+wind have improved much in last 10 yrs
Nuclear still needs least mining + critical minerals per GWh
Cu, steel, Ni, Li, U, Ag offer ways to improve mining footprint further thebreakthrough.org/issues/energy/…
What inspired this analysis? Energy transition mining remains divisive, but discussions often cite flawed or out-of-date data, or end up handwavy. For this analysis, we wanted to make an up-to-date comparison, w transparent methodology using public sources apps.openei.org/REMPD/
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Indeed academic papers (incl my own) tend to lean several yrs out of date.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.