this post was submitted on 21 Dec 2023
195 points (90.5% liked)

Technology

60090 readers
2281 users here now

This is a most excellent place for technology news and articles.

Our Rules

  1. Follow the lemmy.world rules.
  2. Only tech related content.
  3. Be excellent to each another!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, to ask if your bot can be added please contact us.
  9. Check for duplicates before posting, duplicates may be removed

Approved Bots

founded 2 years ago
MODERATORS
L3s@lemmy.world
L3s@fry.gs
L4s@fry.gs
L4s@lemmy.world
enu@lemmy.world
195
Nuclear energy is more expensive than renewables, CSIRO report finds (www.abc.net.au)
submitted 1 year ago by L4s@lemmy.world to c/technology@lemmy.world
50 comments fedilink hide all child comments
 

Nuclear energy is more expensive than renewables, CSIRO report finds::Renewable energy provides the cheapest source of new energy for Australia, a new draft report from the CSIRO and energy market operator has found.

you are viewing a single comment's thread
view the rest of the comments
[–] wewbull@feddit.uk 3 points 1 year ago (1 children)

Please do the maths on "lifting weights up a tall tower.

Actually no, I'll do it for you.

Let's raise a metric ton 10 storeys. A storey is about 3 meters, making that 1000kg going 30 meters up. Mass (1000kg) x g (9.81m/s² ≈ 10m/s²) x height (30m) is about 300,000 joules of energy. We don't use joules much, but they are the amount of energy you use is you draw 1w for 1 second. 300,000Ws. 3,600 seconds in an hour, so 83Wh.

Not kWh, Wh. You might run your TV for an hour.

You'd need to lift 100 tons 100 storeys to get it to kWh. 83kWh. A car battery worth of storage.

This is the reason pumped-hydro storage is a thing. To make lifting a mass a decent energy storage solution, you need a lot of mass. About the order of one lake of water. One plant I visited in Scotland has a reservoir of 10 million tons of water elevated 400 meters, to give it 7GWh of storage. That's a fairly small one, and 36 men died building it back in the 50s/60s.

Gravity storage needs BIG numbers.