Waste water
The organic material in wastewater can be converted into energy - for example in the form of biogas.

When you flush the toilet, they celebrate at the wastewater treatment plant

New Danish legislation says it clearly: Wastewater is increasingly becoming a resource that can be utilised and contribute to the green transition – thanks to new technologies and innovative thinking.

30. Jun 2020

Day by day, the energy accounts of many Danish wastewater treatment plants are looking better and better. On one hand, new technologies that save energy and make the plants more energy efficient are continuously implemented. On the other hand, new methods of producing energy – e.g. biogas – constantly increase productivity in the sector.

In other words, the cake gets bigger and bigger for the wastewater companies in terms of energy. This means that wastewater treatment plants in Denmark are getting better at utilising the resources in the wastewater. Not only can they produce the energy they need to treat the wastewater, they are also able to produce enough energy to sell the excess.

“Better utilisation of resources and production of energy is high on the agenda at wastewater treatment plants in Denmark. It is intrinsic to the way Danish wastewater companies think today: That wastewater is a resource and is no longer perceived a waste product,” Thomas Jensen says, who is Head of Department for wastewater treatment plants in NIRAS.

This development is beneficial to the green transition.

Climate legislation expedites the development

On 16 June 2020, the Danish Government with bipartisan support from the Parliament published a new climate agreement for a green waste sector and circular economy as a part of the specific execution of the Climate Act. The agreement sets a direction for the country’s wastewater companies. Among other things, it focuses on the energy consumption in the sector, energy production, and possible export potentials.

“It is especially the large wastewater companies that treat significant amounts of wastewater, who are now able to boost their bottom line in regards to their energy accounts. In many places around Denmark, the development is already in motion,” Thomas Jensen says and continues:

“The development with energy optimisation and energy production in the wastewater sector undoubtably constitutes a huge export potential for Denmark. The experience Danish utilities are currently collecting will beget valuable environmental technology that many other countries need,” Thomas Jensen says.

New report leads the way

A new report devised by NIRAS and VandCenter Syd (a large Danish utility company) for the Danish Environmental Protection Agency outlines both potentials and challenges in the wastewater sector’s energy- and resource utilisation. The report was created based on reviews of eight treatment plants. It will act as an inspirational catalogue for treatment plants and summarise a long list of opportunities, methods, and technologies for increased energy and resource utilisation.

“Broadly speaking, there is a tremendous potential to save and produce energy – and thereby also reduce CO2 emissions – via energy optimisation of wastewater treatment plants. The report highlights a number of these opportunities and technologies – and some of which are completely obvious, with initiatives that are both profitable and have short pay-back periods,” Lars-Christian Sørensen says, who is a senior consultant in NIRAS and project manager on the report.