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The National Grid needs 1,000 hydro plants just to boil tea

When the demand for energy is high, the National Grid turns to the big boys.

As a nation we love tea. We especially love tea during a TV break! This causes a big problem for the National Grid during major events like the Six Nations. Especially if our egg catchers are on the pitch. When it gets to half time everyone decides to get themselves a nice cup of tea which causes a huge amount of strain on the National Grid.

Exhibit A: some tea

During the Rugby World Cup last year we saw a 650 MW increase in demand during the TV break. For context on how much that is, one hydro plant that Bulb has teamed up with is Little Wyvis Hydro in North Scotland. Their output is 680 kW, enough to power nearly 2,000 homes all year. It would take 1,000 of these to produce enough additional power to survive this surge.

This isn't even that high compared to some surges. During the 2003 Rugby World Cup we saw a 2,100 MW surge and Wills and Kate's wedding saw a 2,400 MW rise.

So how does the National Grid handle it?

Enter Dinorwig Power Station. This behemoth has a staggering 1,728 MW capacity. They had to literally hollow out a mountain to install it. Insane. At the time it broke construction records, taking 10 years to remove the 11 billion kg of rock.

What 11 billion kg of rock looks like

This beast was specifically built to handle these sorts of demands. It can't maintain this output for long, but it only needs to run for a few minutes at a time. It has a lake at the top of the mountain and a lake at the bottom. When the grid has too much power they turn the motors on and use it to pump water up to the top lake. When there is too little power they open the floodgates and go from 0 to 100% in less than 16 seconds. Truly amazing.

If you think that's cool, take a look at this article about how Chile is building a hydro plant in the driest desert in the world.

PS: Tourists can go around Dinorweg, so if you're ever at a loose end in North Wales, think about taking a tour. That, or Go Ape, which is pretty fun too.