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Comment by ben_w | Hacker News Reader

Nice to see, I hope it helps people get more cheap energy.

All I have are nits to pick:

> 10.7k TWh globally

This brings back memories of the time I almost shortened "thousand kilometres" to "kkm".

Also, and this is not a criticism of Google, the IEA link on that text looks suspiciously like the IEA is still forecasting linear deployment of PV between 2025 and 2035, despite at least a decade of people pointing at it being historically exponential and asking why they don't assume the exponent will continue — I'm expecting about double their number for PV by 2035, if trends continue.

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>despite at least a decade of people pointing at it being historically exponential and asking they don't assume the exponent will continue.

So crazy and true. Sources:

https://www.economist.com/interactive/essay/2024/06/20/solar...

https://www.exponentialview.co/p/the-forecasters-gap

7 years ago (!): https://xwpxpfefwalgifkr.quora.com/A-modest-proposal-to-the-...

> This brings back memories of the time I almost shortened "thousand kilometres" to "kkm".

For the uninitiated, what's confusing about this? It seems to communicate the intended meaning accurately. Is there some ambiguity here I missed?

I think it's that a thousand terawatts is equivalent to one petawat. So this is 10.7PWh.

Ah so the complaint is of moving the last order of magnitude onto the quantity rather than the unit. I can't imagine this affects readability that much (although I can understand why you'd want to enforce consistency in an academic context).

Sometimes it's useful to distinguish these, though. And after many do have the inexplicable "MM" suffix (ie s thousand-thousand) to suffer through which seems much worse.

Both linear and using the current exponent are likely to be wildly off.

If you assume it’s ~26% annual growth now, and drops by 2% per year so 24% next year then in 10 years you’ll see 4.25x last years installs and the cumulative initiation over the next decade is 2.8x a linear estimate.

IMO that’s probably a reasonable ballpark, though capacity factors are an open question as they could fall dramatically or maintain fairly steady depending on how much grid storage shows up.

> 10.7k TWh globally

Agree I hate this, but at the same time I don't know if I would have groked it correctly on first read if it had listed "10.7Pwh globally". We simply aren't exposed to numbers at that scale on a regular basis.

Not sure what the correct solution is here.

Joules is the solution to both the problems (the second is that Wh for energy is as silly as speed hours for distance)

Watt-hours is a perfectly pragmatic unit. Measure instantaneous power and multiply by a common human unit of time. It's easy to compare.

Part of me is tempted to suggest kilograms as a unit of energy.

428.6 kg relativistic mass-energy equivalent: https://www.wolframalpha.com/input?i=10.7PWh%2F%28c%5E2%29

But then, I am a silly person.

Call the unit "Kilogram-Joules", abbreviate as KgJ and it works pretty damn well and unambiguously.

The problem is we don't live in a society powered by matter-antimatter annihilation reactions, or black evaporation so it's not really useful - unlike say, the electron-volt which at least serves physicists nicely.

>(the second is that Wh for energy is as silly as speed hours for distance)

This would be a devastating own if a single Joule wasn't exactly equal to a Watt-second.

I was reading https://en.wikipedia.org/wiki/International_System_of_Units and a few related the other day for fun and pleasing moment, and one thing I retained from that is that "The kilogram is the only coherent SI unit whose name and symbol include a prefix." Also that the standard explicitly forbid redundant use of prefixes like kilo-kilo-.

I guess that if you want to stick to TWh you can use

- 10700

- 10,700

- 10.7×10³

- 1.07×10⁴

- 10.7e3

- 1.07e4

- 29E8₁₆

SI prefix words are just kind of silly. We should just use the exponent as a number instead of having a different word for every 3 zeros. 10.7 E15 Wh or something similar.

Scales to everything, you do not need to know any mapping, and directly supports mathematical manipulation.

We should also do the same for large number words in general. No thousand, million, billion, etc. E3, E6, E9, etc. Now you can count and represent any meaningful number without needing to memorize a dictionary of words and they would precisely match the unit scale “words”.

I agree! I use ^3 etc for the notation: https://saul.pw/mag

You mean 1.07E16

It's pretty common in some contexts to only use Es for powers of 1000, so 100,000,000 is 100e6 rather than 1e8.

That's commonly called engineering notation.

We should be. Why? Because reasonable estimates of the amount of extra energy contained within the atmosphere due to anthropogenic effects are in the single digit petawatt range. It's a number everyone should be carrying in their heads.

Put a different way: the total annual harvestable solar yield is within an order of magnitude of the energy we've caused to accumulate inside the atmospheric boundary. Think about that, for a second or two.

The correct solution is 10.7Pwh. We are often exposed to 'Peta' when dealing with data.

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

Well, given that the intent is to communicate, using GWh is probably ideal. 10.7 million GWh is probably the easiest to understand and compare, given that GWh is probably the most commonly used unit for this purpose.

EIA Electricity Monthly gives data in certain tables in terms of either million kWh or "thousand megawatthours" which isn't even English. Let's just use J.

> This brings back memories of the time I almost shortened "thousand kilometres" to "kkm".

SI is such a senseless system. Unit prefixes were not a good idea. Did you move the decimal point or just switch to "Mm?"

In that specific case, I chose megameters.

At which point even metric-users who think in km are confused.

Certain things are measured in certain units, prefix included.

This would be like writing interstellar distances in km instead of light years or parsecs.

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