this post was submitted on 17 Sep 2025
303 points (98.4% liked)
Technology
75597 readers
3065 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related news or articles.
- Be excellent to each other!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, this includes using AI responses and summaries. To ask if your bot can be added please contact a mod.
- Check for duplicates before posting, duplicates may be removed
- Accounts 7 days and younger will have their posts automatically removed.
Approved Bots
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Pumped hydro exists.
Do some quick math. How much pumped hydro in terms of acre-feet would be required to power a hypothetical city like Chicago at night? Where would this theoretical reservoir be built?
I can't stop laughing at this as a unit of measurement
It's easier to visualize than 325 kilo-gallons.
I guess if you don't understand units of water per area, then there is no reason to expect you to be able to do any kind of critical analysis about why "pumped hydro" is a problem.
https://en.wikipedia.org/wiki/Acre-foot
I am not American, so why would I use an American unit of measurement?
You can use whatever moon-units you want. I prefer to use people-centric units.
Ok, if you want an approximate American unit equivalent to a megalitre think of it as cube that can fit a blue whale
Dude, people can laugh at a term while still being able to do "critical analysis" 🙄 "foot pound" sounds funny too. People can giggle about Uranus and still be astronomers.
That's a completely unnecessary way to do things. The mistake you're making is that this specific way must provide all power.
It doesn't. You combine methods for a reason. The wind blows at times when the sun isn't shining, and vice versa. We have weather data stretching back many decades to tell us how much a given region will give us of each. From there, you can calculate the maximum lull where neither is providing enough. Have enough storage to cover that lull, and double it as a safety factor.
Getting to 95% water/wind/solar with this method is relatively easy and would be an extraordinary change. Getting all the way to 100% is possible, just more difficult.
Do the math, how much grid-level storage do you need to power a city like chicago assuming zero baseload generation.
But is extremely limited to specific areas with the right geography that are also relatively close to a population centre.
It isn't so much limited by the geography but is made far more cost effective because of it. A long valley with a narrow exit means you don't need to build much dam and store a vast amount of water.
As far as distance from populated areas, I dunno, I live in the UK so its kinda close enough not to matter too much.
Not if you do HVDC lines. Which are a good idea, anyway. In fact, we might not need to build a single new bit of hydro if we have a good set of HVDC lines.