Britain's largest battery is actually a lake

What are we defining as a battery? If it's purely energy storage I think the hydro energy storage facilities (Like Dinorwig in the UK) definitely qualify: [LINK] which has a capacity of 1,800 MW Tom Scott did a video on this here: [VIDEO]

Geographic batteries (potential energy sinks, eg storing water in a reservoir at a higher altitude and releasing it through turbines to a lower one) have operated for decades. Dinorwig in Wales operates a 9GWh capacity at 1.7GW. Far from insignificant, much cheaper (and safer) than the equivalent lithium cells. [VIDEO] To be clear, Dinorwig is not only powered by green methods, but it could.

Kinda surprised to hear that date, as the UK has a pumped hydro plant[1] which started construction in 1974 and opened in 1984; Tom Scott has a YouTube video about it[2]. It's not all underground, but the machinery is built into a hill and it pumps from a reservoir at the bottom up to the top when electricity is cheap, and is used as a fast-startup generator when demand is higher. Is it really more feasible to build the upper reservoir underground, than on top of, somewhere? Surely "on top of" is higher, easier to get to, easier to flatten, and much cheaper? [1] [LINK] [2] [VIDEO]

On TV Pickup, it's no longer such a thing as it was in the 1980s and 1990s; Tom Scott has a video mentioning it - Dinorwig pumped storage hydroelectric power plant in the UK. One of the reasons for building it was to provide power to the UK national grid at short notice, and the national grid organisation would study the TV schedules for the UK's 4-5 terrestrial channels, and put Dinorwig on standby for power generation. Now with so many different channels and streaming, there isn't the same effect of the country all having an ad break at the same time, and Dinorwig's main use now is in balancing calm moments of solar and wind power generation. Source: - [VIDEO]

The solution for things like this is a multi-facet power grid, with renewables, nuclear, and (small ammounts of) fossil fuels, paired with grid-scale energy storage. For example, the pumped hydro station in Wales [0] can store up to 9.1GWh and can push 1.8GW peak, with a spin up time under a minute. Systems like these can serve both as buffers until fossil fuel or nuclear reactors can spin up to peak in the even of wind/solar shortage, and can even serve as overnight generation to replace solar if large enough (given the usually much lower demand at night). If each state was required to implement their own (presumably smaller) grid-scale storage this would have the benefit of removing a single point of failure and spread the cost. A construction project of this scale would also serve to create hundreds or thousands of jobs in various areas, stimulating the economy. Having grid-scale storage would be drastically improved with a smart grid, since it would have much more real-time data on power demands and allow more seamless management of capacity. [0]: [VIDEO]

It used to be, but not anymore, according to a Tom Scott video and interview with people working there. The National Grid used to look at the TV listings and put Dinorwig on standby for busy times, but there's so many TV channels and streaming options now that there isn't so much of a coordinated sharp spike of the whole country doing something at the same time. Its main use now is in balancing calm moments of solar and wind power generation, apparently. Source: - [VIDEO]

Nuclear is strictly a base load power source. It takes on the scale of "many hours" to days to change generation level at a nuke, and there's intense economic pressure to operate them at full capacity as much as possible because its opex is largely fixed and enormous (as is the capex from construction.) This is why all the people shrieking about how evil the public was/is for 'irrationally' hating nuclear and how we need more nuclear (here, on twitter, and reddit) are idiots, especially when they talk about it providing "grid stability" because of those naughty, highly variable renewables. Grid stability comes from fast-reacting power sources like natural gas, hydro, and energy storage systems like pumped hydro and batteries. The most famous example of this is in the UK, where pumped hydro is fast enough to react to "The Great British Kettle Surge" aka TV pickup: [LINK] Video covering Electric Mountain (9GWHr capacity) by Tom Scott: [VIDEO] Any time someone opens their mouth and says nuclear is the solution to "days with no sun or wind", you can immediately discount everything else that comes out of their mouth as being from a person who doesn't understand the first thing about electrical grids/generation. Even if it were feasible to change power levels fast enough to react to wind and solar generation changing from a physics standpoint, no power authority in the world would keep nuclear generation (the most expensive form of power generation already) capacity in reserve for