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Joe DeCarolis

@jfdecarolis.bsky.social

9K followers 240 following 120 posts

Focused on applying state-of-the-art data systems, models, and analysis to inform decision making on energy. Professor at NC State University; served as the 10th Administrator of the U.S. Energy Information Administration. Personal account.

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Joe DeCarolis @jfdecarolis.bsky.social · May 6

Some personal news: This November, I'll be returning to Carnegie Mellon (@cmu.edu) as head of the Department of Engineering and Public Policy (EPP).

I'm honored and excited to help lead EPP into its next chapter.

engineering.cmu.edu/news-events/...

DeCarolis named head of Engineering and Public Policy

Joseph DeCarolis has been named head of the Department of Engineering and Public Policy.

engineering.cmu.edu

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Reposted by Joe DeCarolis

Jeremy Michalek @jmichalek.bsky.social · 16d

Today we submitted our public comment on critical flaws in EPA's rationale for rescinding its authority to regulate greenhouse gas emissions.

This proposed move is a big deal with profound implications for our future. Today's the last day to comment. www.cmu.edu/cit/veg/publ...

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Joe DeCarolis @jfdecarolis.bsky.social · Aug 7

Excellent piece by @bencasselman.bsky.social on the BLS data revisions.

The U.S. Energy Information Administration, another federal statistical agency, faces similar data challenges. The accuracy vs timeliness tradeoff is universal: data collected at higher frequency is inherently noisier.

Ben Casselman @bencasselman.bsky.social · Aug 6

Data revisions are a normal, necessary part of trying to measure a $30 trillion economy in real time. They can also be jarring, especially for people who don't obsessively scrutinize every jobs report.
So I dug into the how and why of revisions. A few big takeaways:
#EconSky

Why the B.L.S. Regularly Revises Jobs Data

www.nytimes.com

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Reposted by Joe DeCarolis

Georg Zachmann @gzachmann.bsky.social · Jun 22

And here the timely EIA data (and analysis) on oil trade volumes through the Strait of Hormuz - 20% of global oil consumption:
www.eia.gov/todayinenerg...

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Joe DeCarolis @jfdecarolis.bsky.social · May 13

I was happy to participate in this event and explain how the U.S. Energy Information Administration meets energy data needs in the United States. 🔌💡

Bruegel @bruegel.org · May 13

💡 ICYMI: Europe’s energy information problem

Europe suffers from an under-provision of energy information. @nworbmot.bsky.social
@jfdecarolis.bsky.social @bmcwilliams.bsky.social &
@gzachmann.bsky.social discussed possible solutions

🔗Watch the event recording:

Europe’s energy information problem

Is Europe flying blind on energy policy — and how can better data help steer the transition?

buff.ly

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Joe DeCarolis @jfdecarolis.bsky.social · May 6

DeCarolis named head of Engineering and Public Policy

Joseph DeCarolis has been named head of the Department of Engineering and Public Policy.

engineering.cmu.edu

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Joe DeCarolis @jfdecarolis.bsky.social · May 5

Wind is hard to model in capacity expansion models because its performance is highly dependent on its spatiotemporal representation. NEMS, like many other models, has a relatively stylized representation of wind resources.

Reposted by Joe DeCarolis

Rep. Sean Casten @casten.house.gov · Apr 30

If you want to lower energy costs for Americans, you must first understand the US energy system. You can't do that without the robust, accurate data the EIA provides.

The Trump Administration's haphazard dismantling of the EIA will hurt our ability to increase access to cheap, reliable energy.

Over 100 employees leave US EIA, putting crucial energy data at risk, sources say

The U.S. government's energy statistics arm is set to lose over 100 employees after the Trump administration's latest round of resignation offers, putting at risk some of the most closely watched energy reports globally, three sources told Reuters.

www.reuters.com

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Joe DeCarolis @jfdecarolis.bsky.social · Apr 18

Last year we also released an open source python dashboard that enables comparisons across AEO editions: github.com/EIAgov/dash-...

(Looks like it hasn't been updated with AEO2025 data yet.)

GitHub - EIAgov/dash-benchmark

Contribute to EIAgov/dash-benchmark development by creating an account on GitHub.

github.com

Joe DeCarolis @jfdecarolis.bsky.social · Apr 18

All credit goes to EIA staff. (I departed EIA on Jan. 20.)

The EIA Retrospective Report, released every other year, calculates statistics across previous AEO editions: www.eia.gov/outlooks/aeo...

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

That's all for now.

Again, I appreciate the dedication of EIA staff to produce the AEO under challenging circumstances.

And remember EIA's transparency. Don't like a result? Run NEMS with your own assumptions: github.com/EIAgov/NEMS

GitHub - EIAgov/NEMS

Contribute to EIAgov/NEMS development by creating an account on GitHub.

github.com

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

If you’re curious about the Trump Administration’s reaction to these independently produced results: www.energy.gov/articles/doe...

DOE Statement on EIA Annual Energy Outlook

The Department of Energy (DOE) today released the following statement from DOE Spokesperson Andrea Woods on the U.S. Energy Information Administration (EIA) Annual Energy Outlook 2025

www.energy.gov

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

That’s a brief overview of some key results. Remember, modeling assumptions were frozen in December 2024. The effects of Trump’s executive orders and tariff policy, among other factors, could have a significant impact on these projections.

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

EV sales also hit a hard upper limit around 55% of new sales. I suspect this has to do with the relative economics between the different vehicle classes as well as details in the consumer choice model. In future AEO editions, EIA should explore assumptions that could lead to higher EV deployments.

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Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

Finally, here’s a look at electric vehicle sales. Excluding several recent transportation-related regulations has a big impact on electric vehicle (EV) deployment.

Electric vehicle share of new vehicle sales from EIA's Annual Energy Outloook 2025.

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

You can see from the figure above that electrified transport has a significant impact on electricity demand – note the difference between the Reference case and Alternative Transportation case.

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

Overall, total electricity generation increases nearly 50% from 2024-2050. This increase is due to the electrification of end-uses, like transportation, as well as increases in existing sources of electricity demand, like data centers.

Total electricity generation from EIA's Annual Energy Outlook 2025.

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Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

And finally, here’s generation from natural gas, which declines over time in most cases as renewables take up an increasing share of generation.

Natural gas-fired generation projections from EIA's Annual Energy Outlook 2025.

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Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

Here’s nuclear generation. Consistent with past AEO editions, nuclear energy remains relatively flat but with some variation. For example, the Low Oil and Gas Supply case leads to more expensive gas, which incentivizes new nuclear capacity in later years.

Nuclear generation projections from EIA's Annual Energy Outlook 2025.

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

Here’s coal. You can see the effect of the EPA 111d regulations on coal generation – it forces nearly full coal retirement by 2040. Note: “Alternative Electricity” removes those new regulations.

Coal-fired electricity generation projections from EIA's Annual Energy Outlook 2025.

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

Let’s step through the full set of projections for each major source of electricity generation.

Here’s renewables. (Unfortunately, wind and solar are lumped together in the tables.) Note the marked increases in renewable generation and slowdown in later years when the IRA tax credits expire.

Renewables (wind + solar) generation from EIA's Annual Energy Outlook 2025.

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

Here’s a view into the electric sector, with the AEO2023 Reference case, current Reference case, and Alternative Electricity case. Note the consistently high renewables generation, between 60-70% across these three cases.

Electricity generation by source from EIA's Annual Energy Outlook 2025

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

So as renewable penetration increases and end uses are electrified, all else equal, it decreases the need for thermal-based primary energy sources.

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Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

EIA changed its primary energy accounting for noncombustible renewables: www.eia.gov/totalenergy/...

In AEO2025, 1 unit of solar or wind electricity = 1 unit of primary energy. So 1 unit of solar or wind displacing 1 unit of fossil electricity reduces fossil primary energy by 2-3 units (2nd Law).

U.S. Energy Information Administration - EIA - Independent Statistics and AnalysisU.S. Energy Information Administration (EIA) - Pub

www.eia.gov

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

Here's U.S. primary energy consumption. You can see substantial reductions from AEO2023 and through 2040. What’s going on?

Renewables, mostly solar and wind, are an increasing share of the electricity mix. End-use electrification is also increasing. What does that have to do with primary energy?

Total primary energy from EIA's Annual Energy Outlook 2025.

Joe DeCarolis @jfdecarolis.bsky.social · Apr 17

The 2050 Reference case emissions are 17% lower in AEO2025 than AEO2023. It’s largely due to the IRA, EPA regulations, and continued cost declines in renewables and batteries. Emissions tend to flat-line around 2040 as IRA credits expire and growing energy demands exert influence.