You can see Berlin’s east-west divide from space

Berlin from space, as of April 2013. Image: Colonel Chris Hadfield, Nasa.

When you look at maps of Berlin made in the decades before 1989, it’s impossible not to notice the physical fact of the city's political divisions. Some maps replaced one half of the city with a blank space; others painfully warped geography to delete one side altogether. 

Looking at maps of the city today, it seems like it's once again a unified whole. You’d have to work hard to pick out exactly where the wall once stood.

The same isn't true of aerial photographs, however. In 2013, astronaut Chris Hadfield took a photo of the city from the 200 mile-high vantage point of International Space Station, and something immediately stuck out. To the west, the lights are white; to the east, they’re yellow. The boundary is a sharp, clear line, mirroring where the wall once stood. Hadfield tweeted the photo with the comment

Berlin at night. Amazingly, I think the light bulbs still show the East/West division from orbit.

It’s not immediately obvious why this should be. After all, the wall fell over 20 years before Hadfield took his photo, and you’d imagine large chunks of infrastructure, including street lights, would have been replaced in that time, especially if the eastern ones were out of date. But apparently, not so much. Soon after Hadfield’s photo did the rounds on social media, Christa Mientus-Schirmer, a member of the city government, told the Guardian:

Although we’ve made a lot of progress in the 20 years since the wall fell, we haven’t had the money we would have liked to equalise the two parts of the city. 

A member of Berlin’s street furniture department got a little more technical, telling the publication:

In the eastern part there are sodium vapour lamps with a yellower colour. And in the western parts there are fluorescent lamps... which produce a whiter colour.

The significance of the lights as a reminder of the once-divided city isn’t lost on residents, either. On the 25th anniversary of reunification in November 2014, an artist used 8,000 glowing balloons to recreate the wall's division: 

Image: German Foreign Office.

There’s currently a push within the EU to replace a million streetlights throughout Europe with new, low-emisison models. These would give that whiter light, so it could be that, just as the remaining sections of the wall are disappearing, the light disparity will fade with time. 

While we’re here, a few other things stick out when you view the city from above. That white blob in the centre of the image (and, incidentally, on the eastern side of the divide) is Alexanderplatz, a central square and transit hub that’s undergone renovation since reunification. This explains its relative brightness compared to the yellower areas around it:

This triangular area of brightness on the top left is Tegel airport – you’d have a hard job missing it as an airline pilot:

And finally, here's a photo taken from space of Berlin during the day by the European space agency and beamed back to earth via laser

Click for a larger image.

Not a division in sight.

 
 
 
 

The mountain in North Wales that tried to stop the UK’s blackout

Elidir Fawr, the mountain in question. Image: Jem Collins.

Last Friday, the UK’s National Grid turned to mush. Not the official term perhaps, but an accurate one after nearly one million people were left without power across the country, with hundreds more stranded at train stations – or even on trains (which isn’t nearly as fun as it might immediately sound). 

Traffic lights stopped working, back-up power failed in hospitals, and business secretary Andrea Leadsom launched an investigation into exactly what happened. So far though, the long and short of it is that a gas-fired power station in Bedfordshire failed just before 5 o’clock, followed just two minutes later by Hornsea offshore wind farm. 

However, amid the resulting chaos and inevitable search to find someone to blame for the outage, a set of mountains (yes, mountains) in North Wales were working extremely hard to keep the lights on.

From the outside, Elidir Fawr, doesn’t scream power generation. Sitting across from the slightly better known Mount Snowdon, it actually seems quite passive. After all, it is a mountain, and the last slate quarry in the area closed in 1969.

At a push, you’d probably guess the buildings at the base of the mountain were something to do with the area’s industrial past, mostly thanks to the blasting scars on its side, as I did when I first walked past last Saturday. 

But, buried deep into Elidir Fawr is the ability to generate an astounding 1,728 megawatts of electricity – enough to power 2.5 million homes, more than the entire population of the Liverpool region. And the plant is capable of running for five hours.

Dubbed by locals at the ‘Electric Mountain’, Dinorwig Power Station, is made up of 16km of underground tunnels (complete with their own traffic light system), in an excavation which could easily house St Paul’s Cathedral.

Instead, it’s home to six reversible pumps/turbines which are capable of reaching full capacity in just 16 seconds. Which is probably best, as Londoners would miss the view.

‘A Back-Up Facility for The National Grid’

And, just as it often is, the Electric Mountain was called into action on Friday. A spokesperson for First Hydro Company, which owns the generators at Dinorwig, and the slightly smaller Ffestiniog, both in Snowdonia, confirmed that last Friday they’d been asked to start generating by the National Grid.

But just how does a mountain help to ease the effects of a blackout? Or as it’s more regularly used, when there’s a surge in demand for electricity – most commonly when we all pop the kettle on at half-time during the World Cup, scientifically known as TV pick-up.

The answer lies in the lakes at both the top and bottom of Elidir Fawr. Marchlyn Mawr, at the top of the mountain, houses an incredible 7 million tonnes of water, which can be fed down through the mountain to the lake at the bottom, Llyn Peris, generating electricity as it goes.


“Pumped storage technology enables dynamic response electricity production – ofering a critical back-up facility during periods of mismatched supply and demand on the national grid system,” First Hydro Company explains.

The tech works essentially the same way as conventional hydro power – or if you want to be retro, a spruced up waterwheel. When the plant releases water from the upper reservoir, as well as having gravity on their side (the lakes are half a kilometre apart vertically) the water shafts become smaller and smaller, further ramping up the pressure. 

This, in turn, spins the turbines which are linked to the generators, with valves regulating the water flow. Unlike traditional UK power stations, which can take hours to get to full capacity, at Dinorwig it’s a matter of 16 seconds from a cold start, or as little as five if the plant is on standby.

And, designed with the UK’s 50hz frequency in mind, the generator is also built to shut off quickly and avoid overloading the network. Despite the immense water pressure, the valves are able to close off the supply within just 20 seconds. 

At night, the same thing simply happens in reverse, as low-cost, surplus energy from the grid is used to pump the water back up to where it came from, ready for another day of hectic TV scheduling. Or blackouts, take your pick.

Completed in 1984, the power station was the product of a decade of work, and the largest civil engineering project commissioned at the time – and it remains one of Europe’s largest manmade caverns. Not that you’d know it from the outside. And really, if we’ve learned anything from this, it’s that looks can be deceiving, and that mountains can actually be really damn good at making electricity. 

Jem Collins is a digital journalist and editor whose work focuses on human rights, rural stories and careers. She’s the founder and editor of Journo Resources, and you can also find her tweeting @Jem_Collins.