Wastewater treatment and energy production

Turning wastewater into green energy

Using a waste product in terms of sludge for green energy is financially and environmentally a very good case. Thus, we produce energy in all our five wastewater treatment plants. The vision for our new WWTP - Aarhus ReWater is to extract products that can be further processed into high-value items such as proteins and biopolymers.

Less dependent on energy

Producing your own energy makes you less dependent on electricity and the market price on this. Gas production is fluctuating and therefore we have gas tanks that we can use for leveling the gas production.

Also, if electricity is expensive, we can use our gas storage. However, becoming totally independent of the grid is not possible. E.g. by huge rainfall we need a lot of electricity to pump water. On the other hand, we can sell energy at surplus production.

An efficient energy production

The most efficient energy production requires both primary steps and a digester as the energy is three times higher for primary sludge. Gas from the digester drives a gas engine producing both electricity and heat.

Marselisborg WWTP is energy self-sufficient beyond 100 percent. The plant is both power station and a bio refinery where energy is produced from wastewater.

An additional advantage having energy production connected to your wastewater treatment is that 40 % of the sludge rots in the process and therefore expenses for disposing are minimized.

Building the resource plant of the future

Aarhus ReWater is a new and groundbreaking way to treat wastewater. The vision is to create the world's most resource-efficient treatment plant.

The goal is to convert wastewater into energy and products, which is why we also call it a resource facility. Eventually, we should be able to extract products that can be further processed into high-value items such as proteins and biopolymers.

Aarhus ReWater