Ask Lemmy

26858 readers

1664 users here now

A Fediverse community for open-ended, thought provoking questions

Please don't post about US Politics. If you need to do this, try [email protected]

Rules: (interactive)

1) Be nice and; have fun

Doxxing, trolling, sealioning, racism, and toxicity are not welcomed in AskLemmy. Remember what your mother said: if you can't say something nice, don't say anything at all. In addition, the site-wide Lemmy.world terms of service also apply here. Please familiarize yourself with them

2) All posts must end with a '?'

This is sort of like Jeopardy. Please phrase all post titles in the form of a proper question ending with ?

3) No spam

Please do not flood the community with nonsense. Actual suspected spammers will be banned on site. No astroturfing.

4) NSFW is okay, within reason

Just remember to tag posts with either a content warning or a [NSFW] tag. Overtly sexual posts are not allowed, please direct them to either [email protected] or [email protected]. NSFW comments should be restricted to posts tagged [NSFW].

5) This is not a support community.

It is not a place for 'how do I?', type questions. If you have any questions regarding the site itself or would like to report a community, please direct them to Lemmy.world Support or email [email protected]. For other questions check our partnered communities list, or use the search function.

Reminder: The terms of service apply here too.

Partnered Communities:

Logo design credit goes to: tubbadu

founded 1 year ago

MODERATORS

[email protected]

What are some promising solutions to solar power's lack of night time availability? Is "transoceanic power transportation" on the list? (lemmy.myserv.one)

submitted 11 months ago* (last edited 11 months ago) by [email protected] to c/[email protected]

38 comments fedilink hide all child comments

EDIT: Submarine power transportation is indeed on the list

Not transoceanic, but there are two projects currently proposed that will -- when constructed -- break the current record for the "longest undersea power transmission cable" (a record currently held by the North Sea Link at 720 km, or 450 miles.)

One of these projects is the Xlinks Morocco-UK Power Project which aims to lay 3,800 km (2,400 miles) of cable and sell Morocco's solar power to England.

There is, as of yet, not enough cable in the world to even begin this project. The company proposing the project is building factories to produce this cable.

The other is the Australia-Asia Power Link, which aims to provide Australian solar power to Singapore using a 4,500 km (2,800 miles) undersea cable.

Where the Xlinks project ran into a "not enough cable in the world" problem, Sun Cable's AAPL has apparently been running into a "not enough money in the world" problem, as it has repeatedly gotten into trouble with its investors.

EDIT: But also, storage is scaling up

@[email protected] provided a fantastic link to a lot of energy storage mediums that are already in use in various grids across the world. These include (and the link the professor provided gives an excellent short summary on each)

Pumped hydroelectric
Compressed Air Energy Storage (CAES)
Flywheels
Supercapacitors
And just plain batteries

Also, this wasn't in the Gumby's answer, but Finland's Vatajankoski power plant uses a hot sand battery during its high-demand, low-production hours.

Hydrogen is projected to grow

@[email protected] noted that hydrogen has advantages no other energy storage medium possesses: duration of storage and ease of piping/shipping. This is probably why numerous governments are investing in hydrogen production, and why Wood Mackenzie projects what looks like a 200-fold increase in production by the year 2050. (It's a graph. I'm looking at a graph, so I am only estimating.)

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

[–] [email protected] 3 points 11 months ago* (last edited 11 months ago) (1 children)

The statistic you're looking for is energy density. It's usually expressed as Watthour per kilo(Wh/kg). Li-ion batteries are somewhere around 300Wh/kg, or about 1 megajoule though less if you're making it into a building.

Lifting a big weight provides you with Mass x 9.81 x Height amount of joules. So lifting 1 kg for 100m gives you 1x10x100~ 1 kilojoule.

So, to charge my 300kg, 32.000 Wh Nissan leaf battery (130Wh/kg, what you get when you actually build batteries in the real world), you would need to lift a mass of 115tons to 100 meters. So to charge a single car, at 100% efficiency, you need to lift 72 entire cars. Just so I can drive to work and back. And real-world efficiency is far below 100%, just think of the friction.

I think you've spotted the reason why we don't actually build gravity batteries. Imagine lifting 115 tons to 100m, that requires a massive crane, itself weighting nearly half that. That's why all gravity storage in existence basically consists of pumping water uphill, onto pre-existing mountains and lakes that nobody had to fabricate out of concrete and steel.

[–] [email protected] 2 points 11 months ago

There's a company in the UK that proposes building gravity batteries using existing shafts that were excavated for mining.