Britain's largest battery is actually a lake

Dinorwig Power Station, otherwise known as Electric Mountain, is a pumped-storage hydro station in Llanberis, Wales. And yes: it's Britain's largest battery. Here's how it works, and why some of the things you think you know about TV pickups might not be so true any more.

Camera op: Ryan Priestnall

and on Instagram as tomscottgo

[ogrejd]

"...this rainy bit of Wales". Well, that narrows it down a little. :P

[robscallon]

This is one of my favorite channels on YouTube

[Zadster]

Fun fact, Dinorwig is so powerful that it can perform a "black start". In other words, it can bump start the *entire* UK National Grid.

[colinhiggins]

I was in charge of removing the last major bit of rock (in the draft tube valve gallery for those of a technical bent) in 1979 as a student engineer. Amazing place and even more awe inspiring when it was an empty hole with no machinery!

[Airanbanshee]

'a swimming pool every second'
I thought that's US customary unit, never knew British also use it!

[lowercaserho]

I remember begrudgingly going on a geography field trip with my school to this place, back in the mid 90s. And now, here I am, over 20 years later, watching a YouTube video about the same thing, willingly and happily.

[mr.nerd.]

Electric Mountain sounds like the name of a place in a Pokémon game.

[emmanuelrodriguez]

As a costarican (my country produces 90% of electricity by dams) i cannot imagine pumping up a reservoir just to cover on demand peaks, but as an engineer, I'm way more impressed of stopping such a huge flow of water in 10-30 seconds. The guys who designed the relief valves and system surely had the most funny and stressful job of the project.

[zainsinclair]

Hydroelectricity is genuinely such a phenomenal invention. Here in Quebec, the entire province runs on hydro, powered by the St. Laurence river for major areas like Montreal and surrounding suburbs.

[DavidS-qnjm]

When 'Engie' was under that guy's name, I thought that was Tom's pet name for an engineer.

[megs]

Electric Mountain just sounds like a Disney ride.

[Wordsnwood]

Niagara Falls has something kind of like this, only they don't need to use pumps to fill it. They have large reservoirs, and and night they divert water from upstream into the reservoir, which they can draw down during the day. This helps with higher daytime electrical usage needs, but also helps with daytime tourists, as they don't want to divert so much of Niagara Falls to use for electricity that it disappoints tourists.

[emiliofernandez]

UNESCO has chosen Thomas Scott of Britania as a World Heritage Site, congrats

[Awntry]

Thank you, Tom! I watched this video just a week before my Advanced Human Geography paper for CIE A Level and one of the questions I was given in that paper was: "‘Producing energy from renewable resources is not the answer to meeting energy demand.’ How far do you agree?". I mentioned this lake as one of the case studies to support my argument. I got an A grade in Geography and I got my best mark from this paper.

[ClarinoI]

I saw the title: Britain's Largest Battery Is Actually A Cake.
Have to say I did a double take.

[oofed]

"How can a youtube video have this much production?" Is what i ask myself everytime i see a Tom Scott video.

[HarleyAMV]

Seeing that massive lever lifting as if weightless honestly gave me chills

[VanishMe]

The sound at 2:43 is really cool. It sounds like it's straight out of a sci-fi movie or something.

[peteg]

I went here a couple of years ago and the sheer size of the place amazed me. The valves are absolutely enourmous and to think they can move so fast at a moments notice is incredible.

[chairmakerPete]

This has to be the immediate way to solve the intermittency problem of windmills and solar. It's easily understood, and notwithstanding the enormous engineering challenges (which are at least well understood) it's do-able right now.

Scotland and Wales surely have a lot of potential here to boost their economies.