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Marselisborg WWTP is one of the world's most power producing plants from wastewater

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Showcase for the world

Marselisborg Treatment Plant acts as a showcase for the world. As Denmark and California have decided to work together to improve the water sector, Marselisborg plays an important role in representing a treatment plant that shows excellent results in energy efficiency and biogas recovery.

Energy for the whole water cycle

Marselisborg Wastewater Treatment Plant has been transformed from an energy consumer to an energy producing plant.

Production of energy from wastewater is no new invention. However, it is new that a wastewater treatment plant can produce more energy than is needed to run the plant, based on normal household wastewater.

The wastewater treatment plant produces enough energy to cover 94 percent of all the energy used for the whole water cycle in the catchment area, from water production, water distribution over wastewater pumping to wastewater treatment.

Sustainable development at Marselisborg Wastewater Treatment plant from 2010-2016.

Main activities
2010-16: Optimization of Power Consumption and Production
2010-11: Replacement of 2 biogas engines
2011: Replacement of blower
2013: Sale of surplus heat
2015: Sidestream anammox
2015: Replacement of 1 biogas engine.

Arhus Vand A/S
Gunnar Clausens Vej 34
8260 Viby J

Phone +45 89 47 10 00

Aarhus Vand covers a service area of 11,600 ha:
350,000 people are connected
Industry 36,000 PE

We deliver 15 mill. m3 drinking water per year:
9 waterworks
100 wells

We transport and treat 30 mill. m³ wastewater per year:
4 wastewater treatment plants
103 pumping stations
2.200 km sewage pipes
Storm water detention basins approx. 60,000 m3.

Energy Scores

160% renewable energy. 40% more electricity is produced than the plant needs.
Bioenergy to electricity and heat


Grid Value: 60% more energy is produced than the plant needs including heat recovery.
Electricity and hot water for the grid


The Goal is to produce twice as much energy than the plant needs.
Bioenergy to electricity. Heat recovery
Panorama photo

Marselisborg is a popular energy self-suffcient resource plant


Delegations from many countries visit the Marselisborg wastewater treatment plant in Aarhus. Here a delegation from American water agencies is given a tour by Flemming Husum.

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Our aim is to offer and develop resource efficient services throughout the entire water cycle. We aim to create a climate-adapted, healthy environment together with growth and exports for the benefit of customers and stakeholders.

We only use the energy we produce – energy neutral
We supply energy to others – net energy producing
We have a balanced CO2 account (carbon footprint).


Marselisborg Treatment Plant is part of Aarhus Vand (Aarhus Water).

Business type Water treatment

Bio energy, Energy Efficiency
Water industry
Water utility

WASTEWATER TO POWER. Super green wastewater treatment. In 2017, the Marselisborg Wastewater Treatment Plant produced more energy than it needed to run its own business. The Super Geen E Score in 2017 was 160 including heat recovery. The plant produces 40% more electricity than it needs to run the plant.

SURPLUS ENERGY FOR THE GRID. Energy sold to the grid. The Marselisborg Wastewater Treatment Plant distributes energy to the City of Aarhus through the electricity grid. Energy from heat recovery is distributed through the district heating system in Aarhus. The plant produces 2.5 GW of heat for the district heating system.

BIOENERGY PRODUCTION. Energy produced from biogas. The independent energy-based Marselisborg Wastewater Treatment Plant functions solely on energy produced from biogas.

POWER PLANT PLAN. Reduce greenhouse gasses. The Marselisborg Wastewater Treatment Plant strives to be even more energy efficient, with the goal of producing twice as much energy as they use. This would raise the Super Green E Score to 200!

BIOSOLIDS TO BIOGAS. Energy recovery technology. The technology upgrade that the Marselisborg Wastewater Treatment Plant made from 2005 to 2015 included the implementation of new energy efficient biogas engines (CHP,) resulting in an increase in electricity production of about 1 GWh per year. The biogas engines are provided by NISSEN Energy Technology.

ADVANCED BIOLOGICAL PROCESS. Improved wastewater treatment efficiency. The Marselisborg Wastewater Treatment Plant uses a sludge liquor treatment based on the anammox process.

PHOSPHORUS RECYCLING. Nutrient recovery. The Marselisborg Wastewater Treatment Plant recovers phosphorus. The nutrient is captured at a separate facility at the plant and packed for further recycling.

ECO-CITY PARTICIPATION. Achieve city and county goal. The Marselisborg Wastewater Treatment Plant is a utility service that helps the city be eco-friendly by recovering biogas resources and providing electricity for the city. Aarhus's goal is to be a clean energy city by 2035. Aarhus is part of the region/county of Midtjylland in Denmark.

CITIZEN'S WATER. Environmentally friendly water. The Marselisborg Wastewater Treatment Plant is a utility service under Aarhus Water that enables consumers to live a greener lifestyle. Aarhus is the second largest city in Denmark. Marselisborg WWTP treats most of the water in Aarhus.

ENERGY SAVING TECHNOLOGY. Efficiency optimization. The Marselisborg Wastewater Treatment Plant made a technology upgrade by installing a new abs turbo compressor, which increases the energy efficiency of the aeration process. The plant also installed new biogas engines provided by Nissen.

ENERGY SAVING DRIVES. Advanced low voltage SCADA control system. The Marselisborg Wastewater Treatment Plant made a technology upgrade by installing 290 VLT Aqua Drives (modular AC drives) in the water supply and wastewater handling system. 140 VLT drives are installed on all rotating elements in the wastewater facility. Additional 150 VLT drives control the sewage channelization and distribution system. The drives installed are made by Danfoss.

BIG WATER OPTIMIZATION. Upgrade investment. The Marselisborg Wastewater Treatment Plant serves 350,000 people. After undergoing approximately 3 million dollars in optimization and renovation from 2010 to 2016, Aarhus’s Marselisborg Wastewater Treatment Plant is now capable of creating heat and electricity from biogas. Most of the installed technologies have a payback time of less than 5 years.


PLANT DEVELOPMENT. Wastewater treatment plant masterplan. The Marselisborg Wastewater Treatment Plant is scheduled to be transformed by building the Marselisborg ReWater resource plant closer to the Eastern Harbor in Aarhus. The new treatment plant and the Egaa Treatment Plant plants that together will service approximately 480,000 people in the Aarhus Municipality by 2026. This transition from originally 17 plants to two plants will increase the efficiency of wastewater treatment.


UN’s 17 GLOBAL GOALS. Sustainable development plan. Marselisborg Wastewater Treatment Plant administrered under Aarhus Water maintains a strategic focus on the environment and the climate. Aarhus Water integrates the global targets in their Strategy 2020 and in the projects where they are relevant.


CSR CERTIFIED COMPANY. Social accountability. Marselisborg WWTP under Aarhus Water is a CSR certified company. Aarhus Water has full control of topics within social accountability: Consumer relations, the environment, the climate and working conditions, business ethics, human rights and contribution to the development of local society.



posted by Expert Panel California Seats