Going Underground

Next Stop: Ostbahnhof

We’re on the S-bahn in the big city of Berlin, ready to go underground. But first, we have to get to the construction site behind the Eastern train station.

By us, I mean myself and Musa, my intern, who is a whizz with filming and post-production. We’ve been invited by the City Energy Solutions team to go into the sewers of Berlin to film their latest renewable energy installation. It’s a waste-to-heat project that puts a new heat exchanger installation into the over 100 year-old sewers. This technology then feeds the heat into the new building, which is still under construction, directly overhead.

One this is for certain: it's going to be smelly. We’re only uncertain of how bad it will be.

Nothing for a Rainy Day

This is our second foray out to the Ostbahnhof. Upon our first arrival, the water in the sewer was over 1 m in depth. That made it too dangerous for us to descend down – and it also covered up what we were trying to film. The rainy weather was against us.

But we got lucky, because one week later, the water level went down and we got geared up to climb into the smelly depths of Berlin. 

How smelly was it?

It wasn’t that bad! I mean, it was no bed of roses, and yes, we saw raw sewage. But the air was bearable and we didn’t need any masks. Suffice it to say that it was just appropriately stinky.

Our safety equipment consisted of cloth safety suits (in blue), white helmets and big yellow galoshes. To get our phones and cameras into the sewer, we were given a bucket, which was later lowered down with a rope and hook.


Going into the hole was the hardest part. You have to swing your legs over the sandbags and head down the ladder, which ends in just a few holes in the wall where you have to place your feet. Slow & steady wins the race! Caution kept us safe and we made it down into the brick canal.

Once we had our cameras, it was time to start filming! First, we started slowly walking down the new heat exchanger installation. We had to walk right on top of it, as it was positioned right down on the sewer floor. Pipes are located to the left and right of the installation, and the wastewater flows through and over the metal pieces in the middle.

The low temperature heat from the sewage is then pumped all the way down the installation to the building, some 200 meters further down the street. We walked the entire length of the construction, asked a lot of questions, examined every single feed-in pipe and got a lot of answers from our jolly construction manager with an extremely thick southern German accent.

Urban Energy Transition

What became clear to us, there in the dark, dank sewer: the guys working down there every day are our heroes. Also, this is how we are making the urban energy transition a reality. These solutions are now always fancy and futuristic. They’re sometimes just a very simple technology that goes into a space that we don’t think about too often.

These heat exchangers are providing renewable & recyclable heating & cooling for the brand new building, which will have office and retail space for Zalando, a German fashion company. If only they could check out sewer style!

This was a once in a lifetime opportunity. I’m thankful to everyone in the City Energy Solutions team who got us involved in this project. 

For more information on our City Energy Solutions, look here: https://www.eon.com/en/business-customers/community-solutions.html

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