m55au (u/m55au) - Readit News

m55au commented on Python is not a great language for data science blog.genesmindsmachines.c... · Posted by u/speckx

noitpmeder · 23 days ago

I don't know about _squillions_, but numpy definitely has _requirements_, even if they're not represented as such in the python graph.

e.g.

  https://github.com/numpy/numpy/blob/main/.gitmodules (some source code requirements)
  https://github.com/numpy/numpy/tree/main/requirements (mostly build/ci/... requirements)
  ...

m55au · 23 days ago

They're not represented, because those are build-time dependencies. Most users when they do pip install numpy or equivalent, just get the precompiled binaries and none of those get installed. And even if you compile it yourself, you still don't need those for running numpy.

m55au commented on Python is not a great language for data science blog.genesmindsmachines.c... · Posted by u/speckx

roadside_picnic · 24 days ago

> (n - 1)

It's also funny that one would write their own standard deviation function and include Bessel's correction. Usually if I'm manually re-implementing a standard deviation function it's because I'm afraid the implementors blindly applied the correction without considering whether or not it's actually meaningful for the given analysis. At the very least, the correct name for what's implemented there should really be `sample_std_dev`.

m55au · 24 days ago

It is sadly really inconsistent. The stdlib statistics has two separate functions, stdev for sample and pstdev for population. Numpy and pandas both have .std() with ddof (delta degrees of freedom) as a parameter, but numpy defaults to 0 (population) and pandas to 1 (sample).

m55au commented on Python is not a great language for data science blog.genesmindsmachines.c... · Posted by u/speckx

throwaway2037 · 24 days ago

I hear this so much from Python people -- almost like they are paid by the word to say it. Is it different from Perl, Ruby, Java, or C# (DotNet)? Not in my experience, except people from those communities don't repeat that phrase so much.

The irony here: We are talking about data science. 98% of "data science" Python projects start by creating a virtual env and adding Pandas and NumPy which have numerous (really: squillions of) dependencies outside the foundation library.

m55au · 24 days ago

Someone correct me if I'm completely wrong, but by default (i.e. precompiled wheels) numpy has 0 dependencies and pandas has 5, one of which is numpy. So not really "squillions" of dependencies.

pandas==2.3.3

├── numpy [required: >=1.22.4, installed: 2.2.6]

├── python-dateutil [required: >=2.8.2, installed: 2.9.0.post0]

│ └── six [required: >=1.5, installed: 1.17.0]

├── pytz [required: >=2020.1, installed: 2025.2]

└── tzdata [required: >=2022.7, installed: 2025.2]

m55au commented on Solar energy is now the cheapest source of power, study surrey.ac.uk/news/solar-e... · Posted by u/giuliomagnifico

toomuchtodo · 2 months ago

https://www.energy-storage.news/global-bess-deployments-in-h...

https://about.bnef.com/insights/clean-transport/china-alread...

https://www.iea.org/commentaries/the-battery-industry-has-en...

https://elements.visualcapitalist.com/visualizing-chinas-bat...

m55au · 2 months ago

It is surprisingly hard to find reliable figures. Best I could do was a global solar installation of 2-3 TW and global BESS of around 200 GW/500 GWh right now.

China is leading in both, but I'm more interested in local BESS and other storage deployments locally in northern Europe. I think for example Spain started getting more heavily involved only after their massive blackout. According to those links there is a very large overcapacity in battery production, but I don't see it reflected here. I'm sure it will happen at some point though.

m55au commented on Solar energy is now the cheapest source of power, study surrey.ac.uk/news/solar-e... · Posted by u/giuliomagnifico

magicalhippo · 2 months ago

They also have limits on how much power they can transfer before the lines sag too much.

Here in Norway the limitations of our rather poorly connected energy grid has become very apparent last few years, with 100x price difference between regions that aren't that far apart physically.

While we've been paying "winter prices" during summer, up north they've shut down hydro plants since the prices there are so low it's less than operating costs.

m55au · 2 months ago

I looked at tomorrow's (8th of October 2025) prices in Norway and Sweden. Northern Norway drops down to (negative!) -15 €/MWh at 17:45 while southern Sweden peaks at 190 €/MWh at the same time. So that's that for buying "from across the continent", let alone from your neighbors or even your own small country. I'm not sure that even the suggested reconductoring would help that much.

To answer ajross: I'm quite sure that the shutdown of Ringhals and Barsebäck in southern Sweden has had a much greater impact on their and likely southern Norway's prices as well than building for example 10 times the equivalent solar capacity in Spain. It is not even about losses, but just the grid capacity. Theoretically the prices in Nord Pool (from southern France and western Ireland to northern Norway and eastern Baltics) should be equal. As pointed out, in practice they vary wildly. And in principle it can get even worse. It would not be too unrealistic to have negative prices in northern Norway and rolling blackouts in southern Sweden at the same time. I'll leave it as an exercise to the reader how the latter can even happen when Sweden has enough capacity to meet its power demand at that time.

m55au commented on Solar energy is now the cheapest source of power, study surrey.ac.uk/news/solar-e... · Posted by u/giuliomagnifico

ZeroGravitas · 2 months ago

The issue was that the decarbonisation of electricity (and therefore society) would slow or stop before we'd decarbonise if expensive solar lost any of its market. Not cheap energy, that is a good thing.

Between batteries, wind, demand response, EVs etc. that slowdown doesn't seem likely to happen.

And the lure of cheaper energy expands solar out horizontally to new markets, speeding up global decarbonisation.

m55au · 2 months ago

I don't think it will happen either, but I do think there is a bit of imbalance developing in the whole system right now.

For example a decade ago electricity prices in Nord Pool were relatively stable (and reasonable/lowish). Now it is quite common to either have 0 or even negative prices during summer and artificially set maximums in the autumn/winter. IIRC, the rules were that if the price hit 60% of the maximum, it had to be raised by 1000 €/MWh. It got to 4000 €/MWh (which is 4 € or $4.7/kWh) in 2022 and was supposed to be raised by another 1000, but it was decided not to do it, so I think it stands there right now. But in any case, this is a ridiculous price. As are the negative ones.

m55au commented on Solar energy is now the cheapest source of power, study surrey.ac.uk/news/solar-e... · Posted by u/giuliomagnifico

sowbug · 2 months ago

Smart water heaters are interesting, too (though not grid scale). They can use a power surplus during the day to overheat water, reducing the power demand at night. I assume they're smart enough to keep delivering water at a safe temperature.

m55au · 2 months ago

At some point of adaption everything becomes grid scale

https://en.wikipedia.org/wiki/TV_pickup

m55au commented on Solar energy is now the cheapest source of power, study surrey.ac.uk/news/solar-e... · Posted by u/giuliomagnifico

ViewTrick1002 · 2 months ago

Today storage is enabling renewables to fill the gap during wind lulls and nights.

m55au · 2 months ago

Yes, but storage has been lagging behind and when it catches up is to be seen.

m55au commented on Solar energy is now the cheapest source of power, study surrey.ac.uk/news/solar-e... · Posted by u/giuliomagnifico

ZeroGravitas · 2 months ago

This was one of the actual problems highlighted by the people who coined the term "duck curve" over a decade ago.

One of the main ways we've avoided this problem so far is that solar kept getting cheaper.

So it's not really a problem caused by cheap solar, it's just basic market competition, lots of supply with no barrier to entry drives prices down towards the long term marginal cost.

m55au · 2 months ago

Right, but would not marginal cost approaching zero amplify this problem under the current market system (and without any other mitigations)? So not exactly causal, but making it from a small to a bigger issue.

m55au commented on Solar energy is now the cheapest source of power, study surrey.ac.uk/news/solar-e... · Posted by u/giuliomagnifico

jaggederest · 2 months ago

This is really a non-problem. Curtailment is easy and doesn't cost anything, it just needs a slightly better feedback mechanism than the current grid supplies, but honestly even a 24hr timer and ammeter would do it.

m55au · 2 months ago

This is not about grid balance, so I'm not sure what you mean here by curtailment.

It's about nobody making any money, so there will be no incentive to continue building solar.