Building an Urban Resource Factory

Avedöre: changing perception on wastewater

Innovative concepts of advanced wastewater treatment plants (WWTPs) have already been proposed in order to maximize the energy recovery from wastewater while minimizing the energy demand for its treatment, thus changing the perception of wastewater from waste to resource.

The combination of technologies proposed in EC demonstration project Powerstep will lead to design of energy-positive WWTP.

One innovative way to achieve this goal is biogas valorization and especially the power-to-gas concept. Combining power-to-gas facilities within WWTPs has been proposed relatively recently and generally with the advent of biological methanation technologies. Combining power-to-gas within a WWTP is particularly interesting because the by-products heat and oxygen can be recycled on-site and because WWTPs are usually situated close to demand centers, allowing the gas to be injected into a low-pressure distribution.

At the WWTP Avedøre, Denmark, Powerstep focusses on the integration of biomethanation testing the “power-to-gas” concept by operating the world-largest plant.

WWTP as a Smart-grid solution

By 2020, 80% of Denmark’s energy supply will come from green sources (i.e. wind, biomass). Unlike these fluctuating sources of energy, Avedøre provides a smart-grid solution.

A 1 megawatt (MW) biological methanisation plant has been erected to convert biogas CO2 to methane. The goal is to produce gas of a quality suited for direct injection into the Danish National Gas Grid. In a short-time, it converts electrical energy to chemical energy by converting the biogas CO2 component into bio-methane.

Market penetration and valorization

Powerstep uses concepts and technologies that have been tested in laboratories and pilot scale plants. Their full-scale commercial references with a reliable assessment of process efficiencies under realistic conditions remain at stake. Powerstep aims to demonstrate their viability to ensure a successful market deployment of the new technology.

All in all Powerstep strives hard to convert waste into resource. It provides a fully integrated urban solution for energy production and consumption.