Brown gold: Treated sewage could heat one-third of Prague

After all, this is one energy resource that is literally inexhaustible and domestically produced

The City of Prague has plans to develop a new residential district for 25,000 people on a hundred-hectare brownfield in Bubny-Zátory. This time around though, urban planning is taking into account current crises, such as fossil fuel dependency and energy security, to offer an innovative solution – using treated sewage surplus heat to keep homes warm in winter.

For this purpose, a new energy centre will be built next to the wastewater treatment plant on Císařský island and near the planned district. The idea behind it is simple, install 12 heat pumps and channel the heat where it can be of benefit – 200,000 households.

Don’t let heat go to waste, let waste go for heating

“The (energy centre) project has been in the making for about two years. It uses the heat of wastewater that is treated on Císařsky island. Every second, three cubic meters of treated wastewater leave the treatment plant, which even in the coldest months has a temperature higher than ten degrees. We have a huge opportunity to use this water to obtain heat for up to a third of Prague. It has been working successfully for decades in Denmark or Sweden, and there is no reason why it should not be the same here. Moreover, sewage is the only raw material that Prague will always have enough of," stated Petr Hlaváček, 1^st Deputy Mayor of Prague, as quoted by Prazsky Patriot.

The Bubny-Zátory area sits on a peninsula formed by a bend of Prague’s Vltava River and thus enjoys a fairly central location that has been unutilized for decades. The development, however, apart from granting more housing units has the unique chance to serve as the platform for new future-proof solutions, making it a model district in terms of sustainability.

The first housing units in the residential quarter will be ready by 2025, though the entire district will be completed by 2040. The jewel of the new district will be the upcoming Vltava Philharmonic, which too will be heated and cooled with this sustainable approach.