Technology

34806 readers

198 users here now

This is the official technology community of Lemmy.ml for all news related to creation and use of technology, and to facilitate civil, meaningful discussion around it.

Ask in DM before posting product reviews or ads. All such posts otherwise are subject to removal.

Rules:

1: All Lemmy rules apply

2: Do not post low effort posts

3: NEVER post naziped*gore stuff

4: Always post article URLs or their archived version URLs as sources, NOT screenshots. Help the blind users.

5: personal rants of Big Tech CEOs like Elon Musk are unwelcome (does not include posts about their companies affecting wide range of people)

6: no advertisement posts unless verified as legitimate and non-exploitative/non-consumerist

7: crypto related posts, unless essential, are disallowed

founded 5 years ago

MODERATORS

[email protected]

352

Europe’s deepest mine to become giant gravity battery (www.independent.co.uk)

submitted 9 months ago by [email protected] to c/[email protected]

94 comments fedilink hide all child comments

An abandoned mine in Finland is set to be transformed into a giant battery to store renewable energy during periods of excess production.

The Pyhäsalmi Mine, roughly 450 kilometres north of Helsinki, is Europe’s deepest zinc and copper mine and holds the potential to store up to 2 MW of energy within its 1,400-metre-deep shafts.

The disused mine will be fitted with a gravity battery, which uses excess energy from renewable sources like solar and wind in order to lift a heavy weight. During periods of low production, the weight is released and used to power a turbine as it drops.

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 7 points 9 months ago* (last edited 9 months ago) (2 children)

Run the numbers.

How heavy a boulder? 10,000kg?

Potential energy is mass x height, so 10,000kg x 1,400m which is 14MJ of energy. Sounds like a lot, right?

One Joule is a watt flowing for a second and 1,000 watts flowing for 3,600 seconds is 1kWh. 3,600,000 Joules or 3.6MJ. So our 10 ton rock up a 1.4km shaft only stores 4kWhs? 60¢ of electricity?

Everything is linear here, so even having a 100 ton rock will only get us to half a EV battery.

Edit: if you're wondering where the other 90 cents went, this example won't produce two megawatts. It would only produce about 700 kilowatts.

[–] [email protected] 1 points 9 months ago (1 children)

You missed a factor of ten from the gravitational field strength, but still not great. Their heat batteries work better when it comes to heating, but that is mostly limited to just that.

[–] [email protected] 1 points 9 months ago* (last edited 9 months ago)

Oh yes, mgh not mh. You're right

[–] laughterlaughter 1 points 8 months ago* (last edited 8 months ago)

Thanks for doing the math and for expanding.

The way I see it is: if I gather all the electricity I use to power my appliances in a week and just for one home - my home (fridge, heat, washing machines, vacuum cleaner, lightbulbs, laptop), and use it to lift that rock, how high will that rock get?

Also, I wasn't even picturing a rock that small (10,000 kgs in water can be stored half a bedroom of a midsized apartment. Let's just assume that it would take about the same volume in "rock.") I was picturing a rock that's 10m by 10m by 100m tall. More like 10,000,000 kgs.